2024 |
Georgopoulou, Dimitra G; Vouidaskis, Charalabos; Papandroulakis, Nikos Swimming behavior as a potential metric to detect satiation levels of European seabass in marine cages Journal Article Frontiers in Marine Science, 11 , pp. 1350385, 2024, ISSN: 2296-7745. @article{georgopoulou_swimming_2024, title = {Swimming behavior as a potential metric to detect satiation levels of European seabass in marine cages}, author = {Dimitra G Georgopoulou and Charalabos Vouidaskis and Nikos Papandroulakis}, url = {https://imbbc.hcmr.gr/wp-content/uploads/2024/03/2024-Georgopoulou-Frontiers-MS-13.pdf https://www.frontiersin.org/articles/10.3389/fmars.2024.1350385/full}, doi = {10.3389/fmars.2024.1350385}, issn = {2296-7745}, year = {2024}, date = {2024-03-11}, urldate = {2024-03-11}, journal = {Frontiers in Marine Science}, volume = {11}, pages = {1350385}, abstract = {Aquaculture is anticipated to contribute to two-thirds of the world’s fish consumption by 2030, emphasizing the need for innovative methods to optimize practices for economic viability, social responsibility, and environmental sustainability. Feeding practices play a pivotal role in aquaculture success and the feeding requirements are dynamic, influenced by factors like fish size, environmental conditions, and health status necessitating ongoing improvements in feeding practices. This study addresses a critical gap in feeding control systems in sea cages. It introduces a continuous, real-time monitoring system for analyzing the feeding behavior of European seabass, employing advanced AI models (YOLO and DEEPSORT) and computer vision techniques. The investigation focuses on key parameters, including speed and the newly defined feeding behavior index (FBI), to evaluate swimming responses under varying feeding scenarios exploring meal frequency, feeding time, and feeding quantity. The findings reveal a sensitivity of fish speed and the feeding behavior index (FBI) to different feeding scenarios, elucidating distinct behavioral patterns in response to varying frequencies, times, and quantities of feeding, such as increased activity in the morning relative to later times and the emergence of asymmetric activity patterns when fish are underfed or overfed. Notably, this study is one of the few in the field, presenting the development of a continuous, real-time monitoring system for feeding control in sea cages. Simultaneously, it explores reference curves and threshold values to enhance the overall efficacy of feeding control measures.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Aquaculture is anticipated to contribute to two-thirds of the world’s fish consumption by 2030, emphasizing the need for innovative methods to optimize practices for economic viability, social responsibility, and environmental sustainability. Feeding practices play a pivotal role in aquaculture success and the feeding requirements are dynamic, influenced by factors like fish size, environmental conditions, and health status necessitating ongoing improvements in feeding practices. This study addresses a critical gap in feeding control systems in sea cages. It introduces a continuous, real-time monitoring system for analyzing the feeding behavior of European seabass, employing advanced AI models (YOLO and DEEPSORT) and computer vision techniques. The investigation focuses on key parameters, including speed and the newly defined feeding behavior index (FBI), to evaluate swimming responses under varying feeding scenarios exploring meal frequency, feeding time, and feeding quantity. The findings reveal a sensitivity of fish speed and the feeding behavior index (FBI) to different feeding scenarios, elucidating distinct behavioral patterns in response to varying frequencies, times, and quantities of feeding, such as increased activity in the morning relative to later times and the emergence of asymmetric activity patterns when fish are underfed or overfed. Notably, this study is one of the few in the field, presenting the development of a continuous, real-time monitoring system for feeding control in sea cages. Simultaneously, it explores reference curves and threshold values to enhance the overall efficacy of feeding control measures. |
Føre, Martin; Alver, Morten Omholt; Alfredsen, Jo Arve; Rasheed, Adil; Hukkelås, Thor; Bjelland, Hans V; Su, Biao; Ohrem, Sveinung J; Kelasidi, Eleni; Norton, Tomas; Papandroulakis, Nikos Digital Twins in intensive aquaculture — Challenges, opportunities and future prospects Journal Article Computers and Electronics in Agriculture, 218 , pp. 108676, 2024, ISSN: 01681699. @article{fore_digital_2024, title = {Digital Twins in intensive aquaculture — Challenges, opportunities and future prospects}, author = {Martin Føre and Morten Omholt Alver and Jo Arve Alfredsen and Adil Rasheed and Thor Hukkelås and Hans V Bjelland and Biao Su and Sveinung J Ohrem and Eleni Kelasidi and Tomas Norton and Nikos Papandroulakis}, url = {https://imbbc.hcmr.gr/wp-content/uploads/2024/02/2024-Fore-CompElectAgriculture-10.pdf https://linkinghub.elsevier.com/retrieve/pii/S016816992400067X}, doi = {10.1016/j.compag.2024.108676}, issn = {01681699}, year = {2024}, date = {2024-02-19}, urldate = {2024-02-20}, journal = {Computers and Electronics in Agriculture}, volume = {218}, pages = {108676}, keywords = {}, pubstate = {published}, tppubtype = {article} } |
2023 |
Chen, I-Hao; Georgopoulou, Dimitra G; Ebbesson, Lars O E; Voskakis, Dimitris; Lal, Pradeep; Papandroulakis, Nikos Food anticipatory behaviour on European seabass in sea cages: activity-, positioning-, and density-based approaches Journal Article Frontiers in Marine Science, 10 , pp. 1168953, 2023, ISSN: 2296-7745. @article{chen_food_2023, title = {Food anticipatory behaviour on European seabass in sea cages: activity-, positioning-, and density-based approaches}, author = {I-Hao Chen and Dimitra G Georgopoulou and Lars O E Ebbesson and Dimitris Voskakis and Pradeep Lal and Nikos Papandroulakis}, url = {https://imbbc.hcmr.gr/wp-content/uploads/2023/10/2023-Chen-fmars-56.pdf https://www.frontiersin.org/articles/10.3389/fmars.2023.1168953/full}, doi = {10.3389/fmars.2023.1168953}, issn = {2296-7745}, year = {2023}, date = {2023-10-13}, urldate = {2023-10-19}, journal = {Frontiers in Marine Science}, volume = {10}, pages = {1168953}, abstract = {Introduction Farmed fish like European seabass ( Dicentrarchus labrax ) anticipate meals if these are provided at one or multiple fixed times during the day. The increase in locomotor activity is typically known as food anticipatory activity (FAA) and can be observed several hours prior to feeding. Measuring FAA is often done by demand feeders or external sensors such as cameras or light curtains. However, purely locomotor-activity-based FAA may provide an incomplete view of feeding and prefeeding behaviour. Methods Here, we show that FAA can be measured through passive acoustic telemetry utilising three different approaches and suggest that adding more means to food anticipation detection is beneficial. We compared the diving behaviour, acceleration activity, and temperature of 22 tagged individuals over the period of 12 days and observed FAA through locomotor activity, depth position, and density-based unsupervised clustering (i.e., DBSCAN). Results Our results demonstrate that the position- and density-based methods also provide expressions of anticipatory behaviour that can be interchangeable with locomotor-driven FAA or precede it. Discussion We, therefore, support a unified framework for food anticipation: FAA should only describe locomotor-driven FAA. Food anticipatory positioning (FAP) should be a term for position-based (P-FAP) and density-based (D-FAP) methods for food anticipation. Lastly, FAP, together with the newly defined FAA, should become part of an umbrella term that is already in use: food anticipatory behaviour (FAB). Our work provides data-driven approaches to each FAB category and compares them with each other. Furthermore, accurate FAB windows through FAA and FAP can help increase fish welfare in the aquaculture industry, and the more approaches available, the more flexible and more robust the usage of FAB for a holistic view can be achieved.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Introduction Farmed fish like European seabass ( Dicentrarchus labrax ) anticipate meals if these are provided at one or multiple fixed times during the day. The increase in locomotor activity is typically known as food anticipatory activity (FAA) and can be observed several hours prior to feeding. Measuring FAA is often done by demand feeders or external sensors such as cameras or light curtains. However, purely locomotor-activity-based FAA may provide an incomplete view of feeding and prefeeding behaviour. Methods Here, we show that FAA can be measured through passive acoustic telemetry utilising three different approaches and suggest that adding more means to food anticipation detection is beneficial. We compared the diving behaviour, acceleration activity, and temperature of 22 tagged individuals over the period of 12 days and observed FAA through locomotor activity, depth position, and density-based unsupervised clustering (i.e., DBSCAN). Results Our results demonstrate that the position- and density-based methods also provide expressions of anticipatory behaviour that can be interchangeable with locomotor-driven FAA or precede it. Discussion We, therefore, support a unified framework for food anticipation: FAA should only describe locomotor-driven FAA. Food anticipatory positioning (FAP) should be a term for position-based (P-FAP) and density-based (D-FAP) methods for food anticipation. Lastly, FAP, together with the newly defined FAA, should become part of an umbrella term that is already in use: food anticipatory behaviour (FAB). Our work provides data-driven approaches to each FAB category and compares them with each other. Furthermore, accurate FAB windows through FAA and FAP can help increase fish welfare in the aquaculture industry, and the more approaches available, the more flexible and more robust the usage of FAB for a holistic view can be achieved. |
Stavrakidis-Zachou, Orestis; Papandroulakis, Nikos; Lika, Konstadia A bioenergetics approach to modelling tolerance limits under acute thermal stress in farmed finfish Journal Article Frontiers in Marine Science, 10 , pp. 1173358, 2023, ISSN: 2296-7745. @article{stavrakidis-zachou_bioenergetics_2023, title = {A bioenergetics approach to modelling tolerance limits under acute thermal stress in farmed finfish}, author = {Orestis Stavrakidis-Zachou and Nikos Papandroulakis and Konstadia Lika}, url = {https://imbbc.hcmr.gr/wp-content/uploads/2023/06/2023-Stavrakidis-Zachou-Frontiers-MarSci-27.pdf https://www.frontiersin.org/articles/10.3389/fmars.2023.1173358/full}, doi = {10.3389/fmars.2023.1173358}, issn = {2296-7745}, year = {2023}, date = {2023-06-02}, urldate = {2023-06-09}, journal = {Frontiers in Marine Science}, volume = {10}, pages = {1173358}, abstract = {Pinpointing thermal tolerance thresholds for commercially important species, such as aquaculture finfish, under acute and chronic thermal stress is becoming increasingly relevant in the context of climate change. While experimental research, traditionally quantified by the determination of the Critical Thermal Maximum (CTmax), offers valuable insights, it is necessary to further develop appropriate tools to provide predictions and shed light on the underlying mechanisms of thermal tolerance. Bioenergetic models have long been used to study the effects of temperature on fish metabolism under chronic, but rarely under acute, scales. In this study, we present a modelling approach based on the Dynamic Energy Budget (DEB) theory that describes the tolerance limits of fish under acute thermal stress in bioenergetics terms. It adopts the notion of an energy-dependent tolerance to stress and defines acute tolerance limits at the intersection of fundamental energy fluxes, namely those relating to the mobilization of energy and to maintenance costs. To showcase this approach, DEB models for two finfish, the European sea bass ( Dicentrarchus labrax ) and the meagre ( Argyrosomus regius ) were used to run acute thermal challenge simulations and study shifts in the critical temperature achieved by the fish. The results suggest that the model can adequately capture the general tolerance patterns observed experimentally for the two species as well as pinpoint the parameters that may influence them. In particular, the simulations showed a positive relation between acclimation temperature and tolerance while the opposite stands for the body size of the fish, with smaller fish achieving higher critical temperatures than their larger counterparts. Also, tolerance limits were affected by the state of internal reserves, with well-fed fish exhibiting higher values. Finally, the potential application of this modelling approach on higher taxonomic scales was evaluated, by running simulations on species belonging to major fish orders. The preliminary results suggest that the method can capture differences among groups that are consistent with literature, suggesting it may be a realistic mechanistic approach for studying thermal tolerance in ectotherms.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Pinpointing thermal tolerance thresholds for commercially important species, such as aquaculture finfish, under acute and chronic thermal stress is becoming increasingly relevant in the context of climate change. While experimental research, traditionally quantified by the determination of the Critical Thermal Maximum (CTmax), offers valuable insights, it is necessary to further develop appropriate tools to provide predictions and shed light on the underlying mechanisms of thermal tolerance. Bioenergetic models have long been used to study the effects of temperature on fish metabolism under chronic, but rarely under acute, scales. In this study, we present a modelling approach based on the Dynamic Energy Budget (DEB) theory that describes the tolerance limits of fish under acute thermal stress in bioenergetics terms. It adopts the notion of an energy-dependent tolerance to stress and defines acute tolerance limits at the intersection of fundamental energy fluxes, namely those relating to the mobilization of energy and to maintenance costs. To showcase this approach, DEB models for two finfish, the European sea bass ( Dicentrarchus labrax ) and the meagre ( Argyrosomus regius ) were used to run acute thermal challenge simulations and study shifts in the critical temperature achieved by the fish. The results suggest that the model can adequately capture the general tolerance patterns observed experimentally for the two species as well as pinpoint the parameters that may influence them. In particular, the simulations showed a positive relation between acclimation temperature and tolerance while the opposite stands for the body size of the fish, with smaller fish achieving higher critical temperatures than their larger counterparts. Also, tolerance limits were affected by the state of internal reserves, with well-fed fish exhibiting higher values. Finally, the potential application of this modelling approach on higher taxonomic scales was evaluated, by running simulations on species belonging to major fish orders. The preliminary results suggest that the method can capture differences among groups that are consistent with literature, suggesting it may be a realistic mechanistic approach for studying thermal tolerance in ectotherms. |
Chatziantoniou, Andromachi; Papandroulakis, Nikos; Stavrakidis-Zachou, Orestis; Spondylidis, Spyros; Taskaris, Simeon; Topouzelis, Konstantinos Aquasafe: A Remote Sensing, Web-Based Platform for the Support of Precision Fish Farming Journal Article Applied Sciences, 13 (10), pp. 6122, 2023, ISSN: 2076-3417. @article{chatziantoniou_aquasafe_2023, title = {Aquasafe: A Remote Sensing, Web-Based Platform for the Support of Precision Fish Farming}, author = {Andromachi Chatziantoniou and Nikos Papandroulakis and Orestis Stavrakidis-Zachou and Spyros Spondylidis and Simeon Taskaris and Konstantinos Topouzelis}, url = {https://imbbc.hcmr.gr/wp-content/uploads/2023/06/2023-Chatziantoniou-AppSci-26.pdf https://www.mdpi.com/2076-3417/13/10/6122}, doi = {10.3390/app13106122}, issn = {2076-3417}, year = {2023}, date = {2023-05-31}, urldate = {2023-06-08}, journal = {Applied Sciences}, volume = {13}, number = {10}, pages = {6122}, abstract = {Marine aquaculture has been expanding rapidly in recent years, driven by the growing demand for marine products. However, this expansion has led to increased competition for space and resources with other coastal zone activities, which has resulted in the need for larger facilities and the relocation of operations to offshore areas. Moreover, the complex environment and exposure to environmental conditions and external threats further complicate the sustainable development of the sector. To address these challenges, new and innovative technologies are needed, such as the incorporation of remote sensing and in-situ data for comprehensive and continuous monitoring of aquaculture facilities. This study aims to create an integrated monitoring and decision support system utilizing both satellite and in-situ data to monitor aquaculture facilities on various scales, providing information on water quality, fish growth, and warning signs to alert managers and producers of potential hazards. This study focuses on identifying and estimating parameters that affect aquaculture processes, establishing indicators that can act as warning signs, and evaluating the system’s performance in real-life scenarios. The resulting monitoring tool, called “Aquasafe”, was evaluated for its effectiveness and performance by test users through real-life scenarios. The results of the implemented models showed high accuracy, with an R2 value of 0.67. Additionally, users were generally satisfied with the usefulness of the tool, suggesting that it holds promise for efficient management and decision making in marine aquaculture.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Marine aquaculture has been expanding rapidly in recent years, driven by the growing demand for marine products. However, this expansion has led to increased competition for space and resources with other coastal zone activities, which has resulted in the need for larger facilities and the relocation of operations to offshore areas. Moreover, the complex environment and exposure to environmental conditions and external threats further complicate the sustainable development of the sector. To address these challenges, new and innovative technologies are needed, such as the incorporation of remote sensing and in-situ data for comprehensive and continuous monitoring of aquaculture facilities. This study aims to create an integrated monitoring and decision support system utilizing both satellite and in-situ data to monitor aquaculture facilities on various scales, providing information on water quality, fish growth, and warning signs to alert managers and producers of potential hazards. This study focuses on identifying and estimating parameters that affect aquaculture processes, establishing indicators that can act as warning signs, and evaluating the system’s performance in real-life scenarios. The resulting monitoring tool, called “Aquasafe”, was evaluated for its effectiveness and performance by test users through real-life scenarios. The results of the implemented models showed high accuracy, with an R2 value of 0.67. Additionally, users were generally satisfied with the usefulness of the tool, suggesting that it holds promise for efficient management and decision making in marine aquaculture. |
Sánchez-Cueto, Pablo; Stavrakidis-Zachou, Orestis; Clos-Garcia, Marc; Bosch, Montse; Papandroulakis, Nikos; Lladó, Salvador Mediterranean Sea heatwaves jeopardize greater amberjack’s (Seriola dumerili) aquaculture productivity through impacts on the fish microbiota Journal Article ISME Communications, 3 (1), pp. 36, 2023, ISSN: 2730-6151. @article{sanchez-cueto_mediterranean_2023, title = {Mediterranean Sea heatwaves jeopardize greater amberjack’s (Seriola dumerili) aquaculture productivity through impacts on the fish microbiota}, author = {Pablo Sánchez-Cueto and Orestis Stavrakidis-Zachou and Marc Clos-Garcia and Montse Bosch and Nikos Papandroulakis and Salvador Lladó}, url = {https://imbbc.hcmr.gr/wp-content/uploads/2023/06/2023-Sanchez-Cueto-ISME-23.pdf https://www.nature.com/articles/s43705-023-00243-7}, doi = {10.1038/s43705-023-00243-7}, issn = {2730-6151}, year = {2023}, date = {2023-05-26}, urldate = {2023-06-02}, journal = {ISME Communications}, volume = {3}, number = {1}, pages = {36}, abstract = {Abstract Climate change is dramatically increasing the frequency and severity of marine heatwaves (MHWs) in the Mediterranean basin, strongly affecting marine food production systems. However, how it will shape the ecology of aquaculture systems, and the cascading effects on productivity, is still a major knowledge gap. The present work aims to increase our understanding of future impacts, caused by raising water temperatures, on the interaction between water and fish microbiotas, and consequential effects upon fish growth. Thus, the bacterial communities present in the water tanks, and mucosal tissues (skin, gills and gut), of greater amberjack farmed in recirculatory aquaculture systems (RAS), at three different temperatures (24, 29 and 33 °C), were characterized in a longitudinal study. The greater amberjack ( Seriola dumerili ) is a teleost species with high potential for EU aquaculture diversification due to its fast growth, excellent flesh quality and global market. We show that higher water temperatures disrupt the greater amberjack’s microbiota. Our results demonstrate the causal mediation exerted by this bacterial community shifts on the reduction of fish growth. The abundance of members of the Pseudoalteromonas is positively correlated with fish performance, whereas members of the Psychrobacter, Chryseomicrobium, Paracoccus and Enterovibrio are suggested as biomarkers for dysbiosis, at higher water temperatures. Hence, opening new evidence-based avenues for the development of targeted microbiota-based biotechnological tools, designed to increase the resilience and adaptation to climate change of the Mediterranean aquaculture industry.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Abstract Climate change is dramatically increasing the frequency and severity of marine heatwaves (MHWs) in the Mediterranean basin, strongly affecting marine food production systems. However, how it will shape the ecology of aquaculture systems, and the cascading effects on productivity, is still a major knowledge gap. The present work aims to increase our understanding of future impacts, caused by raising water temperatures, on the interaction between water and fish microbiotas, and consequential effects upon fish growth. Thus, the bacterial communities present in the water tanks, and mucosal tissues (skin, gills and gut), of greater amberjack farmed in recirculatory aquaculture systems (RAS), at three different temperatures (24, 29 and 33 °C), were characterized in a longitudinal study. The greater amberjack ( Seriola dumerili ) is a teleost species with high potential for EU aquaculture diversification due to its fast growth, excellent flesh quality and global market. We show that higher water temperatures disrupt the greater amberjack’s microbiota. Our results demonstrate the causal mediation exerted by this bacterial community shifts on the reduction of fish growth. The abundance of members of the Pseudoalteromonas is positively correlated with fish performance, whereas members of the Psychrobacter, Chryseomicrobium, Paracoccus and Enterovibrio are suggested as biomarkers for dysbiosis, at higher water temperatures. Hence, opening new evidence-based avenues for the development of targeted microbiota-based biotechnological tools, designed to increase the resilience and adaptation to climate change of the Mediterranean aquaculture industry. |
Valdivieso, Alejandro; Sánchez-Baizán, Núria; Mitrizakis, Nikos; Papandroulakis, Nikos; Piferrer, Francesc Aquaculture, 563 , pp. 738918, 2023, ISSN: 00448486. @article{valdivieso_development_2023, title = {Development of epigenetic biomarkers with diagnostic and prognostic value to assess the lasting effects of early temperature changes in farmed fish}, author = {Alejandro Valdivieso and Núria Sánchez-Baizán and Nikos Mitrizakis and Nikos Papandroulakis and Francesc Piferrer}, url = {https://imbbc.hcmr.gr/wp-content/uploads/2022/11/2023-Valdivieso-3.pdf https://linkinghub.elsevier.com/retrieve/pii/S0044848622010353}, doi = {10.1016/j.aquaculture.2022.738918}, issn = {00448486}, year = {2023}, date = {2023-01-04}, urldate = {2022-11-10}, journal = {Aquaculture}, volume = {563}, pages = {738918}, keywords = {}, pubstate = {published}, tppubtype = {article} } |
2022 |
Chatziantoniou, Andromachi; Spondylidis, Spyros Charalampis; Stavrakidis-Zachou, Orestis; Papandroulakis, Nikos; Topouzelis, Konstantinos Dissolved oxygen estimation in aquaculture sites using remote sensing and machine learning Journal Article Remote Sensing Applications: Society and Environment, 28 , pp. 100865, 2022, ISSN: 23529385. @article{chatziantoniou_dissolved_2022, title = {Dissolved oxygen estimation in aquaculture sites using remote sensing and machine learning}, author = {Andromachi Chatziantoniou and Spyros Charalampis Spondylidis and Orestis Stavrakidis-Zachou and Nikos Papandroulakis and Konstantinos Topouzelis}, url = {https://imbbc.hcmr.gr/wp-content/uploads/2022/11/2022-Chatziantoniou-RSA-76.pdf https://linkinghub.elsevier.com/retrieve/pii/S2352938522001732}, doi = {10.1016/j.rsase.2022.100865}, issn = {23529385}, year = {2022}, date = {2022-11-18}, urldate = {2022-11-18}, journal = {Remote Sensing Applications: Society and Environment}, volume = {28}, pages = {100865}, keywords = {}, pubstate = {published}, tppubtype = {article} } |
Georgopoulou, Dimitra G; Fanouraki, Eleftheria; Voskakis, Dimitris; Mitrizakis, Nikos; Papandroulakis, Nikos European seabass show variable responses in their group swimming features after tag implantation Journal Article Frontiers in Animal Science, 3 , pp. 997948, 2022, ISSN: 2673-6225. @article{georgopoulou_european_2022, title = {European seabass show variable responses in their group swimming features after tag implantation}, author = {Dimitra G Georgopoulou and Eleftheria Fanouraki and Dimitris Voskakis and Nikos Mitrizakis and Nikos Papandroulakis}, url = {https://imbbc.hcmr.gr/wp-content/uploads/2022/09/2022-Georgopoulou-62.pdf https://www.frontiersin.org/articles/10.3389/fanim.2022.997948/full}, doi = {10.3389/fanim.2022.997948}, issn = {2673-6225}, year = {2022}, date = {2022-09-01}, urldate = {2022-09-26}, journal = {Frontiers in Animal Science}, volume = {3}, pages = {997948}, abstract = {The usefulness of acoustic telemetry on the study of movements, interactions, and behaviors has been revealed by many field and laboratory studies. The process of attaching acoustic tags on fish can, however, impact their physiological, behavioral, and growth performance traits. The potential negative effects are still unknown for several species and behavioral attributes. Previous studies have attempted to shed light on the effects of tag implantation on fish, focusing mainly on fish growth and physiological parameters, and one or two behavioral properties mainly on the individual level. However, the effect of this procedure could also be expressed at the group level. This study investigated the short-term effects of dummy and active body-implanted acoustic tags on the group-level swimming performance of adult European seabass ( Dicentrarchus labrax ) using optical flow analysis. We studied four main swimming performance properties—group speed, alignment (polarization), cohesion, and exploratory behavior. To help in the interpretation of any detected differences, physiological stress-related parameters were also extracted. The results show that the tag implantation procedure has variable effects on the different swimming performance attributes of fish. Group cohesion, polarization, and the group’s exploratory tendency were significantly impacted initially, and the effect persisted but to a lesser extent two weeks after surgery. In contrast, group speed was not affected initially but showed a significant decrease in comparison with the control group two weeks post-surgery. In addition, the physiological parameters tested did not show any significant difference between the control and the treated group 14 days after the onset of the experiment. The findings suggest that the effect of tagging is non-trivial, leading to responses and response times that could affect behavioral studies carried out using acoustic telemetry.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The usefulness of acoustic telemetry on the study of movements, interactions, and behaviors has been revealed by many field and laboratory studies. The process of attaching acoustic tags on fish can, however, impact their physiological, behavioral, and growth performance traits. The potential negative effects are still unknown for several species and behavioral attributes. Previous studies have attempted to shed light on the effects of tag implantation on fish, focusing mainly on fish growth and physiological parameters, and one or two behavioral properties mainly on the individual level. However, the effect of this procedure could also be expressed at the group level. This study investigated the short-term effects of dummy and active body-implanted acoustic tags on the group-level swimming performance of adult European seabass ( Dicentrarchus labrax ) using optical flow analysis. We studied four main swimming performance properties—group speed, alignment (polarization), cohesion, and exploratory behavior. To help in the interpretation of any detected differences, physiological stress-related parameters were also extracted. The results show that the tag implantation procedure has variable effects on the different swimming performance attributes of fish. Group cohesion, polarization, and the group’s exploratory tendency were significantly impacted initially, and the effect persisted but to a lesser extent two weeks after surgery. In contrast, group speed was not affected initially but showed a significant decrease in comparison with the control group two weeks post-surgery. In addition, the physiological parameters tested did not show any significant difference between the control and the treated group 14 days after the onset of the experiment. The findings suggest that the effect of tagging is non-trivial, leading to responses and response times that could affect behavioral studies carried out using acoustic telemetry. |
Bouranta, Andrianna; Tudose, Ioan Valentin; Georgescu, Luciana; Karaiskou, Anna; Vrithias, Nikolaos Rafail; Viskadourakis, Zacharias; Kenanakis, George; Sfakaki, Efsevia; Mitrizakis, Nikolaos; Strakantounas, George; Papandroulakis, Nikolaos; Romanitan, Cosmin; Pachiu, Cristina; Tutunaru, Oana; Barbu-Tudoran, Lucian; Suchea, Mirela Petruta; Koudoumas, Emmanouel 3D Printed Metal Oxide-Polymer Composite Materials for Antifouling Applications Journal Article Nanomaterials, 12 (6), pp. 917, 2022, ISSN: 2079-4991. @article{bouranta_3d_2022, title = {3D Printed Metal Oxide-Polymer Composite Materials for Antifouling Applications}, author = {Andrianna Bouranta and Ioan Valentin Tudose and Luciana Georgescu and Anna Karaiskou and Nikolaos Rafail Vrithias and Zacharias Viskadourakis and George Kenanakis and Efsevia Sfakaki and Nikolaos Mitrizakis and George Strakantounas and Nikolaos Papandroulakis and Cosmin Romanitan and Cristina Pachiu and Oana Tutunaru and Lucian Barbu-Tudoran and Mirela Petruta Suchea and Emmanouel Koudoumas}, url = {https://imbbc.hcmr.gr/wp-content/uploads/2022/05/2022-Bouranta-nanomaterials-19.pdf https://www.mdpi.com/2079-4991/12/6/917}, doi = {10.3390/nano12060917}, issn = {2079-4991}, year = {2022}, date = {2022-03-01}, urldate = {2022-05-09}, journal = {Nanomaterials}, volume = {12}, number = {6}, pages = {917}, abstract = {Current technology to prevent biofouling usually relies on the use of toxic, biocide-containing materials, which can become a serious threat to marine ecosystems, affecting both targeted and nontargeted organisms. Therefore, the development of broad-spectrum, less toxic antifouling materials is a challenge for researchers; such materials would be quite important in applications like aquaculture. In this respect, surface chemistry, physical properties, durability and attachment scheme can play a vital role in the performance of the materials. In this work, acrylonitrile butadiene styrene (ABS)/micro ZnO or nano ZnO composite lattices with different metal oxide contents were developed using 3D printing. Their antifouling behavior was examined with respect to aquaculture applications by monitoring growth on them of the diatoms Navicula sp. and the monocellular algae Chlorella sp. with image analysis techniques. As shown, the presence of metal oxides in the composite materials can bring about antifouling ability at particular concentrations. The present study showed promising results, but further improvements are needed.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Current technology to prevent biofouling usually relies on the use of toxic, biocide-containing materials, which can become a serious threat to marine ecosystems, affecting both targeted and nontargeted organisms. Therefore, the development of broad-spectrum, less toxic antifouling materials is a challenge for researchers; such materials would be quite important in applications like aquaculture. In this respect, surface chemistry, physical properties, durability and attachment scheme can play a vital role in the performance of the materials. In this work, acrylonitrile butadiene styrene (ABS)/micro ZnO or nano ZnO composite lattices with different metal oxide contents were developed using 3D printing. Their antifouling behavior was examined with respect to aquaculture applications by monitoring growth on them of the diatoms Navicula sp. and the monocellular algae Chlorella sp. with image analysis techniques. As shown, the presence of metal oxides in the composite materials can bring about antifouling ability at particular concentrations. The present study showed promising results, but further improvements are needed. |
Cascarano, Maria Chiara; Ruetten, Maja; Vaughan, Lloyd; Tsertou, Maria Ioanna; Georgopoulou, Dimitra; Keklikoglou, Kleoniki; Papandroulakis, Nikos; Katharios, Pantelis Epitheliocystis in Greater Amberjack: Evidence of a Novel Causative Agent, Pathology, Immune Response and Epidemiological Findings Journal Article Microorganisms, 10 (3), pp. 627, 2022, ISSN: 2076-2607. @article{cascarano_epitheliocystis_2022, title = {Epitheliocystis in Greater Amberjack: Evidence of a Novel Causative Agent, Pathology, Immune Response and Epidemiological Findings}, author = {Maria Chiara Cascarano and Maja Ruetten and Lloyd Vaughan and Maria Ioanna Tsertou and Dimitra Georgopoulou and Kleoniki Keklikoglou and Nikos Papandroulakis and Pantelis Katharios}, url = {https://imbbc.hcmr.gr/wp-content/uploads/2022/05/2022-Cascarano-Microorganisms-20.pdf https://www.mdpi.com/2076-2607/10/3/627}, doi = {10.3390/microorganisms10030627}, issn = {2076-2607}, year = {2022}, date = {2022-03-01}, urldate = {2022-05-09}, journal = {Microorganisms}, volume = {10}, number = {3}, pages = {627}, abstract = {Epitheliocystis is a fish gill disease caused by a broad range of intracellular bacteria infecting freshwater and marine fish worldwide. Here we report the occurrence and progression of epitheliocystis in greater amberjack reared in Crete (Greece). The disease appears to be caused mainly by a novel Betaproteobacteria belonging to the Candidatus Ichthyocystis genus with a second agent genetically similar to Ca. Parilichlamydia carangidicola coinfecting the gills in some cases. After a first detection of the disease in 2017, we investigated epitheliocystis in the following year’s cohort of greater amberjack juveniles (cohort 2018) transferred from inland tanks to the same cage farm in the open sea where the first outbreak was detected. This cohort was monitored for over a year together with stocks of gilthead seabream and meagre co-farmed in the same area. Our observations showed that epitheliocystis could be detected in greater amberjack gills as early as a month following the transfer to sea cages, with ionocytes at the base of the gill lamellae being initially infected. Cyst formation appears to trigger a proliferative response, leading to the fusion of lamellae, impairment of gill functions and subsequently to mortality. Lesions are characterized by infiltration of immune cells, indicating activation of the innate immune response. At later stages of the outbreak, cysts were no longer found in ionocytes but were observed in mucocytes at the trailing edge of the filament. Whole cysts appeared finally to be expelled from infected mucocytes directly into the water, which might constitute a novel means of dispersion of the infectious agents. Molecular screening indicates that meagre is not affected by this disease and confirms the presence of previously described epitheliocystis agents, Ca. Ichthyocystis sparus, Ca. Ichthyocystis hellenicum and Ca. Similichlamydia spp., in gilthead seabream. Prevalence data show that the bacteria persist in both gilthead seabream and greater amberjack cohorts after first infection.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Epitheliocystis is a fish gill disease caused by a broad range of intracellular bacteria infecting freshwater and marine fish worldwide. Here we report the occurrence and progression of epitheliocystis in greater amberjack reared in Crete (Greece). The disease appears to be caused mainly by a novel Betaproteobacteria belonging to the Candidatus Ichthyocystis genus with a second agent genetically similar to Ca. Parilichlamydia carangidicola coinfecting the gills in some cases. After a first detection of the disease in 2017, we investigated epitheliocystis in the following year’s cohort of greater amberjack juveniles (cohort 2018) transferred from inland tanks to the same cage farm in the open sea where the first outbreak was detected. This cohort was monitored for over a year together with stocks of gilthead seabream and meagre co-farmed in the same area. Our observations showed that epitheliocystis could be detected in greater amberjack gills as early as a month following the transfer to sea cages, with ionocytes at the base of the gill lamellae being initially infected. Cyst formation appears to trigger a proliferative response, leading to the fusion of lamellae, impairment of gill functions and subsequently to mortality. Lesions are characterized by infiltration of immune cells, indicating activation of the innate immune response. At later stages of the outbreak, cysts were no longer found in ionocytes but were observed in mucocytes at the trailing edge of the filament. Whole cysts appeared finally to be expelled from infected mucocytes directly into the water, which might constitute a novel means of dispersion of the infectious agents. Molecular screening indicates that meagre is not affected by this disease and confirms the presence of previously described epitheliocystis agents, Ca. Ichthyocystis sparus, Ca. Ichthyocystis hellenicum and Ca. Similichlamydia spp., in gilthead seabream. Prevalence data show that the bacteria persist in both gilthead seabream and greater amberjack cohorts after first infection. |
Varamogianni-Mamatsi, Despoina; Anastasiou, Thekla I; Vernadou, Emmanouela; Papandroulakis, Nikos; Kalogerakis, Nicolas; Dailianis, Thanos; Mandalakis, Manolis A Multi-Species Investigation of Sponges’ Filtering Activity towards Marine Microalgae Journal Article Marine Drugs, 20 (1), pp. 24, 2022, ISSN: 1660-3397. @article{varamogianni-mamatsi_multi-species_2022, title = {A Multi-Species Investigation of Sponges’ Filtering Activity towards Marine Microalgae}, author = {Despoina Varamogianni-Mamatsi and Thekla I Anastasiou and Emmanouela Vernadou and Nikos Papandroulakis and Nicolas Kalogerakis and Thanos Dailianis and Manolis Mandalakis}, url = {https://www.mdpi.com/1660-3397/20/1/24}, doi = {10.3390/md20010024}, issn = {1660-3397}, year = {2022}, date = {2022-01-01}, urldate = {2022-02-28}, journal = {Marine Drugs}, volume = {20}, number = {1}, pages = {24}, abstract = {Chronic discharge of surplus organic matter is a typical side effect of fish aquaculture, occasionally leading to coastal eutrophication and excessive phytoplankton growth. Owing to their innate filter-feeding capacity, marine sponges could mitigate environmental impact under integrated multitrophic aquaculture (IMTA) scenarios. Herein, we investigated the clearance capacity of four ubiquitous Mediterranean sponges (Agelas oroides, Axinella cannabina, Chondrosia reniformis and Sarcotragus foetidus) against three microalgal substrates with different size/motility characteristics: the nanophytoplankton Nannochloropsis sp. (textasciitilde3.2 μm, nonmotile) and Isochrysis sp. (textasciitilde3.8 μm, motile), as well as the diatom Phaeodactylum tricornutum (textasciitilde21.7 μm, nonmotile). In vitro cleaning experiments were conducted using sponge explants in 1 L of natural seawater and applying different microalgal cell concentrations under light/dark conditions. The investigated sponges exhibited a wide range of retention efficiencies for the different phytoplankton cells, with the lowest average values found for A. cannabina (37%) and the highest for A. oroides (70%). The latter could filter up to 14.1 mL seawater per hour and gram of sponge wet weight, by retaining 100% of Isochrysis at a density of 105 cells mL−1, under darkness. Our results highlight differences in filtering capacity among sponge species and preferences for microalgal substrates with distinct size and motility traits.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Chronic discharge of surplus organic matter is a typical side effect of fish aquaculture, occasionally leading to coastal eutrophication and excessive phytoplankton growth. Owing to their innate filter-feeding capacity, marine sponges could mitigate environmental impact under integrated multitrophic aquaculture (IMTA) scenarios. Herein, we investigated the clearance capacity of four ubiquitous Mediterranean sponges (Agelas oroides, Axinella cannabina, Chondrosia reniformis and Sarcotragus foetidus) against three microalgal substrates with different size/motility characteristics: the nanophytoplankton Nannochloropsis sp. (textasciitilde3.2 μm, nonmotile) and Isochrysis sp. (textasciitilde3.8 μm, motile), as well as the diatom Phaeodactylum tricornutum (textasciitilde21.7 μm, nonmotile). In vitro cleaning experiments were conducted using sponge explants in 1 L of natural seawater and applying different microalgal cell concentrations under light/dark conditions. The investigated sponges exhibited a wide range of retention efficiencies for the different phytoplankton cells, with the lowest average values found for A. cannabina (37%) and the highest for A. oroides (70%). The latter could filter up to 14.1 mL seawater per hour and gram of sponge wet weight, by retaining 100% of Isochrysis at a density of 105 cells mL−1, under darkness. Our results highlight differences in filtering capacity among sponge species and preferences for microalgal substrates with distinct size and motility traits. |
Tsertou, M I; Papandroulakis, N; Keklikoglou, K; Kalantzi, I; Tsapakis, M; Tsalafouta, A; Pavlidis, M; Antonopoulou, E; Katharios, P Comparative study of Chronic Ulcerative Dermatopathy in cultured meagre, Argyrosomus regius Journal Article Aquaculture, 556 , pp. 738301, 2022, ISSN: 00448486. @article{tsertou_comparative_2022, title = {Comparative study of Chronic Ulcerative Dermatopathy in cultured meagre, Argyrosomus regius}, author = {M I Tsertou and N Papandroulakis and K Keklikoglou and I Kalantzi and M Tsapakis and A Tsalafouta and M Pavlidis and E Antonopoulou and P Katharios}, url = {https://imbbc.hcmr.gr/wp-content/uploads/2022/05/2022-Tsertou-AQUA-pre-print-34.pdf https://linkinghub.elsevier.com/retrieve/pii/S0044848622004173}, doi = {10.1016/j.aquaculture.2022.738301}, issn = {00448486}, year = {2022}, date = {2022-01-01}, urldate = {2022-05-09}, journal = {Aquaculture}, volume = {556}, pages = {738301}, keywords = {}, pubstate = {published}, tppubtype = {article} } |
Papadaki, Maria; Kaitetzidou, Elisavet; Papadakis, Ioannis E; Sfakianakis, Dimitris G; Papandroulakis, Nikos; Mylonas, Constantinos C; Sarropoulou, Elena Temperature-Biased miRNA Expression Patterns during European Sea Bass (Dicentrarchus labrax) Development Journal Article International Journal of Molecular Sciences, 23 (19), pp. 11164, 2022, ISSN: 1422-0067. @article{papadaki_temperature-biased_2022, title = {Temperature-Biased miRNA Expression Patterns during European Sea Bass (Dicentrarchus labrax) Development}, author = {Maria Papadaki and Elisavet Kaitetzidou and Ioannis E Papadakis and Dimitris G Sfakianakis and Nikos Papandroulakis and Constantinos C Mylonas and Elena Sarropoulou}, url = {https://imbbc.hcmr.gr/wp-content/uploads/2022/09/2022-Papadaki-IJMS-65.pdf https://www.mdpi.com/1422-0067/23/19/11164}, doi = {10.3390/ijms231911164}, issn = {1422-0067}, year = {2022}, date = {2022-01-01}, urldate = {2022-09-27}, journal = {International Journal of Molecular Sciences}, volume = {23}, number = {19}, pages = {11164}, abstract = {Environmental effects and, particularly, temperature changes have been demonstrated to influence the activity, function, and well-being of teleosts. Temperature may change seasonally in the wild, and in captivity under aquaculture operations. Moreover, climate change is expected to shift temperature profiles worldwide. MicroRNAs (miRNA) are important temperature-sensitive gene-expression regulators acting at the post-transcriptional level. They are known to be key regulators in development, reproduction, and immune responses. Therefore, early larval development of the European sea bass (Dicentrarchus labrax), one of the most extensively cultured species in Mediterranean aquaculture, was investigated at early rearing temperatures, i.e., 15, 17.5, and 20 °C, in regard to the impact of temperatures on miRNAs through sncRNA high-throughput sequencing but also at the phenotypic level in terms of growth, sex, vision, and skeletal deformities. Expression profiling revealed stage- and temperature-specific miRNA expression targeting genes with roles in reproduction and immune response mainly at the flexion and all-fins stages. Similar stage- and temperature-specific results were also observed concerning the number of rod cells and lower jaw elongation. The present work presents for the first time highly promising results on the influence of early rearing temperature at the post-transcriptional level during European sea bass development, with a putative impact on reproduction and immune response, as well as regarding teleost vision and larval development.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Environmental effects and, particularly, temperature changes have been demonstrated to influence the activity, function, and well-being of teleosts. Temperature may change seasonally in the wild, and in captivity under aquaculture operations. Moreover, climate change is expected to shift temperature profiles worldwide. MicroRNAs (miRNA) are important temperature-sensitive gene-expression regulators acting at the post-transcriptional level. They are known to be key regulators in development, reproduction, and immune responses. Therefore, early larval development of the European sea bass (Dicentrarchus labrax), one of the most extensively cultured species in Mediterranean aquaculture, was investigated at early rearing temperatures, i.e., 15, 17.5, and 20 °C, in regard to the impact of temperatures on miRNAs through sncRNA high-throughput sequencing but also at the phenotypic level in terms of growth, sex, vision, and skeletal deformities. Expression profiling revealed stage- and temperature-specific miRNA expression targeting genes with roles in reproduction and immune response mainly at the flexion and all-fins stages. Similar stage- and temperature-specific results were also observed concerning the number of rod cells and lower jaw elongation. The present work presents for the first time highly promising results on the influence of early rearing temperature at the post-transcriptional level during European sea bass development, with a putative impact on reproduction and immune response, as well as regarding teleost vision and larval development. |
Stavrakidis-Zachou, Orestis; Lika, Konstadia; Pavlidis, Michail; Asaad, Mohamed H; Papandroulakis, Nikos 2022, (Type: dataset). @misc{stavrakidis-zachou_dataset__2022, title = {Dataset_ metabolic scope performance and tolerance of juvenile European sea bass \textit{Dicentrarchus labrax} upon acclimation to high temperatures}, author = {Orestis Stavrakidis-Zachou and Konstadia Lika and Michail Pavlidis and Mohamed H. Asaad and Nikos Papandroulakis}, url = {https://imbbc.hcmr.gr/wp-content/uploads/2022/09/2022-Stavrakidis-Zachou-PLOS-ONE-64.pdf https://zenodo.org/record/6901703}, doi = {10.5281/ZENODO.6901703}, year = {2022}, date = {2022-01-01}, urldate = {2022-09-26}, publisher = {Zenodo}, abstract = {This dataset contains the data associated with the article 'Metabolic scope, performance and tolerance of juvenile European sea bass Dicentrarchus labrax upon acclimation to high temperatures' by Stavrakidis-Zachou et al. accepted for publication on Plos one in July 2022.}, note = {Type: dataset}, keywords = {}, pubstate = {published}, tppubtype = {misc} } This dataset contains the data associated with the article 'Metabolic scope, performance and tolerance of juvenile European sea bass Dicentrarchus labrax upon acclimation to high temperatures' by Stavrakidis-Zachou et al. accepted for publication on Plos one in July 2022. |
2021 |
Papadaki, Maria; Mandalakis, Manolis; Anastasiou, Thekla I; Pouli, Marina; Asderis, Michalis; Katharios, Pantelis; Papandroulakis, Nikos; Mylonas, Constantinos C Fish Physiology and Biochemistry, 47 (6), pp. 1777–1792, 2021, ISSN: 1573-5168. @article{papadaki_histological_2021b, title = {Histological evaluation of sex differentiation and early sex identification in hatchery-produced greater amberjack (Seriola dumerili) reared in sea cages}, author = {Maria Papadaki and Manolis Mandalakis and Thekla I Anastasiou and Marina Pouli and Michalis Asderis and Pantelis Katharios and Nikos Papandroulakis and Constantinos C Mylonas}, url = {https://imbbc.hcmr.gr/wp-content/uploads/2022/01/2021-Papadaki-FFB-82-pre-print.pdf https://doi.org/10.1007/s10695-021-01007-7}, doi = {10.1007/s10695-021-01007-7}, issn = {1573-5168}, year = {2021}, date = {2021-12-01}, urldate = {2021-12-04}, journal = {Fish Physiology and Biochemistry}, volume = {47}, number = {6}, pages = {1777--1792}, abstract = {The histological process of gonadal differentiation, together with the endocrine changes of sex steroid hormones and some of their precursors, was studied in hatchery-produced greater amberjack Seriola dumerili from 101 until 408 days post-hatching (dph), with samplings conducted every 50 days. Histological processing showed that sex differentiation began at 101 dph with the formation of the ovarian cavity in females, while the presumptive males did not yet contain any germ cells in their gonad. At 150 dph, we observed the first germ cells in the developing testes. Sex differentiation in almost all sampled individuals was complete at 408 dph. No size dimorphism was observed between the sexes, and the sex ratio was 1:1, suggesting that there was no influence of early rearing in captivity on sex differentiation. Plasma concentrations of adrenosterone (Ad), androstenedione (Δ4), 11-ketotestosterone (11ΚΤ), testosterone (Τ), estradiol (Ε2), progesterone (P4) and 17,20β-dihydroxy-4-pregnen-3-one (17,20βP) were measured in males and females with the use of liquid chromatography tandem mass spectrometry (LC–MS/MS) to examine their role in the sex differentiation process. From the seven hormones, the only one that exhibited differences between the sexes was 11-KT and the plasma 11-KT concentration was found to be a useful indication of greater amberjack sex. Variations were observed in the mean values of Ad, Δ4, 11-KT, T, P4 and 17,20βP over time in one or both sexes, indicating their involvement in the sex differentiation process.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The histological process of gonadal differentiation, together with the endocrine changes of sex steroid hormones and some of their precursors, was studied in hatchery-produced greater amberjack Seriola dumerili from 101 until 408 days post-hatching (dph), with samplings conducted every 50 days. Histological processing showed that sex differentiation began at 101 dph with the formation of the ovarian cavity in females, while the presumptive males did not yet contain any germ cells in their gonad. At 150 dph, we observed the first germ cells in the developing testes. Sex differentiation in almost all sampled individuals was complete at 408 dph. No size dimorphism was observed between the sexes, and the sex ratio was 1:1, suggesting that there was no influence of early rearing in captivity on sex differentiation. Plasma concentrations of adrenosterone (Ad), androstenedione (Δ4), 11-ketotestosterone (11ΚΤ), testosterone (Τ), estradiol (Ε2), progesterone (P4) and 17,20β-dihydroxy-4-pregnen-3-one (17,20βP) were measured in males and females with the use of liquid chromatography tandem mass spectrometry (LC–MS/MS) to examine their role in the sex differentiation process. From the seven hormones, the only one that exhibited differences between the sexes was 11-KT and the plasma 11-KT concentration was found to be a useful indication of greater amberjack sex. Variations were observed in the mean values of Ad, Δ4, 11-KT, T, P4 and 17,20βP over time in one or both sexes, indicating their involvement in the sex differentiation process. |
Stavrakidis-Zachou, Orestis; Lika, Konstadia; Michail, Pavlidis; Tsalafouta, Aleka; Mohamed, Asaad H; Nikos, Papandroulakis Thermal tolerance, metabolic scope and performance of meagre, Argyrosomus regius, reared under high water temperatures Journal Article 100 , pp. 103063, 2021, ISSN: 03064565. @article{stavrakidis-zachou_thermal_2021, title = {Thermal tolerance, metabolic scope and performance of meagre, Argyrosomus regius, reared under high water temperatures}, author = {Orestis Stavrakidis-Zachou and Konstadia Lika and Pavlidis Michail and Aleka Tsalafouta and Asaad H Mohamed and Papandroulakis Nikos}, url = {https://imbbc.hcmr.gr/wp-content/uploads/2021/09/2021-Stavrakidis-JoTB-65-pre-print.pdf https://linkinghub.elsevier.com/retrieve/pii/S030645652100231X}, doi = {10.1016/j.jtherbio.2021.103063}, issn = {03064565}, year = {2021}, date = {2021-09-01}, urldate = {2021-09-16}, volume = {100}, pages = {103063}, keywords = {}, pubstate = {published}, tppubtype = {article} } |
Oikonomou, Stavroula; Tsakogiannis, Alexandros; Kriaridou, Christina; Danis, Theodoros; Manousaki, Tereza; Chatziplis, Dimitris; Papandroulakis, Nikos; Mylonas, Constantinos C; Triantafyllidis, Alexandros; Tsigenopoulos, Costas S 21 , pp. 100855, 2021, ISSN: 23525134. @article{oikonomou_first_2021, title = {First linkage maps and a pilot QTL analysis for early growth performance in common dentex (Dentex dentex) and sharpsnout seabream (Diplodus puntazzo)}, author = {Stavroula Oikonomou and Alexandros Tsakogiannis and Christina Kriaridou and Theodoros Danis and Tereza Manousaki and Dimitris Chatziplis and Nikos Papandroulakis and Constantinos C Mylonas and Alexandros Triantafyllidis and Costas S Tsigenopoulos}, url = {https://imbbc.hcmr.gr/wp-content/uploads/2021/09/2021-Oikonomou-AquaReports-68.pdf https://linkinghub.elsevier.com/retrieve/pii/S2352513421002714}, doi = {10.1016/j.aqrep.2021.100855}, issn = {23525134}, year = {2021}, date = {2021-09-01}, urldate = {2021-09-22}, volume = {21}, pages = {100855}, keywords = {}, pubstate = {published}, tppubtype = {article} } |
Cascarano, Maria Chiara; Stavrakidis-Zachou, Orestis; Mladineo, Ivona; Thompson, Kim D; Papandroulakis, Nikos; Katharios, Pantelis Mediterranean Aquaculture in a Changing Climate: Temperature Effects on Pathogens and Diseases of Three Farmed Fish Species Journal Article 10 (9), pp. 1205, 2021. @article{cascarano_mediterranean_2021, title = {Mediterranean Aquaculture in a Changing Climate: Temperature Effects on Pathogens and Diseases of Three Farmed Fish Species}, author = {Maria Chiara Cascarano and Orestis Stavrakidis-Zachou and Ivona Mladineo and Kim D Thompson and Nikos Papandroulakis and Pantelis Katharios}, url = {https://imbbc.hcmr.gr/wp-content/uploads/2021/09/2021-Cascarano-pathogens-71.pdf https://www.mdpi.com/2076-0817/10/9/1205}, doi = {10.3390/pathogens10091205}, year = {2021}, date = {2021-09-01}, urldate = {2021-09-22}, volume = {10}, number = {9}, pages = {1205}, abstract = {Climate change is expected to have a drastic effect on aquaculture worldwide. As we move forward with the agenda to increase and diversify aquaculture production, rising temperatures will have a progressively relevant impact on fish farming, linked to a multitude of issues associated with fish welfare. Temperature affects the physiology of both fish and pathogens, and has the potential to lead to significant increases in disease outbreaks within aquaculture systems, resulting in severe financial impacts. Significant shifts in future temperature regimes are projected for the Mediterranean Sea. We therefore aim to review and discuss the existing knowledge relating to disease outbreaks in the context of climate change in Mediterranean finfish aquaculture. The objective is to describe the effects of temperature on the physiology of both fish and pathogens, and moreover to list and discuss the principal diseases of the three main fish species farmed in the Mediterranean, namely gilthead seabream (Sparus aurata), European seabass (Dicentrarchus labrax), and meagre (Argyrosomus regius). We will attempt to link the pathology of each disease to a specific temperature range, while discussing potential future disease threats associated with the available climate change trends for the Mediterranean Sea.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Climate change is expected to have a drastic effect on aquaculture worldwide. As we move forward with the agenda to increase and diversify aquaculture production, rising temperatures will have a progressively relevant impact on fish farming, linked to a multitude of issues associated with fish welfare. Temperature affects the physiology of both fish and pathogens, and has the potential to lead to significant increases in disease outbreaks within aquaculture systems, resulting in severe financial impacts. Significant shifts in future temperature regimes are projected for the Mediterranean Sea. We therefore aim to review and discuss the existing knowledge relating to disease outbreaks in the context of climate change in Mediterranean finfish aquaculture. The objective is to describe the effects of temperature on the physiology of both fish and pathogens, and moreover to list and discuss the principal diseases of the three main fish species farmed in the Mediterranean, namely gilthead seabream (Sparus aurata), European seabass (Dicentrarchus labrax), and meagre (Argyrosomus regius). We will attempt to link the pathology of each disease to a specific temperature range, while discussing potential future disease threats associated with the available climate change trends for the Mediterranean Sea. |
Kourkouta, Chara; Printzi, Alice; Geladakis, George; Mitrizakis, Nikos; Papandroulakis, Nikos; Koumoundouros, George Scientific Reports, 11 (1), pp. 8787, 2021, ISSN: 2045-2322. @article{kourkouta_long_2021, title = {Long lasting effects of early temperature exposure on the swimming performance and skeleton development of metamorphosing Gilthead seabream ( Sparus aurata L.) larvae}, author = {Chara Kourkouta and Alice Printzi and George Geladakis and Nikos Mitrizakis and Nikos Papandroulakis and George Koumoundouros}, url = {https://www.nature.com/articles/s41598-021-88306-4 https://imbbc.hcmr.gr/wp-content/uploads/2021/05/2021-Kourkouta-SciReports-31-1.pdf }, doi = {10.1038/s41598-021-88306-4}, issn = {2045-2322}, year = {2021}, date = {2021-04-01}, urldate = {2021-04-27}, journal = {Scientific Reports}, volume = {11}, number = {1}, pages = {8787}, abstract = {Temperatures experienced during early ontogeny significantly influence fish phenotypes, with clear consequences for the wild and reared stocks. We examined the effect of temperature (17, 20, or 23 °C) during the short embryonic and yolk-sac larval period, on the swimming performance and skeleton of metamorphosing Gilthead seabream larvae. In the following ontogenetic period, all fish were subjected to common temperature (20 °C). The critical swimming speed of metamorphosing larvae was significantly decreased from 9.7 ± 0.6 TL/s (total length per second) at 17 °C developmental temperature (DT) to 8.7 ± 0.6 and 8.8 ± 0.7 TL/s at 20 and 23 °C DT respectively (p textless 0.05). Swimming performance was significantly correlated with fish body shape (p textless 0.05). Compared with the rest groups, fish of 17 °C DT presented a slender body shape, longer caudal peduncle, terminal mouth and ventrally transposed pectoral fins. Moreover, DT significantly affected the relative depth of heart ventricle (VD/TL, p textless 0.05), which was comparatively increased at 17 °C DT. Finally, the incidence of caudal-fin abnormalities significantly decreased (p textless 0.05) with the increase of DT. To our knowledge, this is the first evidence for the significant effect of DT during the short embryonic and yolk-sac larval period on the swimming performance of the later stages.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Temperatures experienced during early ontogeny significantly influence fish phenotypes, with clear consequences for the wild and reared stocks. We examined the effect of temperature (17, 20, or 23 °C) during the short embryonic and yolk-sac larval period, on the swimming performance and skeleton of metamorphosing Gilthead seabream larvae. In the following ontogenetic period, all fish were subjected to common temperature (20 °C). The critical swimming speed of metamorphosing larvae was significantly decreased from 9.7 ± 0.6 TL/s (total length per second) at 17 °C developmental temperature (DT) to 8.7 ± 0.6 and 8.8 ± 0.7 TL/s at 20 and 23 °C DT respectively (p textless 0.05). Swimming performance was significantly correlated with fish body shape (p textless 0.05). Compared with the rest groups, fish of 17 °C DT presented a slender body shape, longer caudal peduncle, terminal mouth and ventrally transposed pectoral fins. Moreover, DT significantly affected the relative depth of heart ventricle (VD/TL, p textless 0.05), which was comparatively increased at 17 °C DT. Finally, the incidence of caudal-fin abnormalities significantly decreased (p textless 0.05) with the increase of DT. To our knowledge, this is the first evidence for the significant effect of DT during the short embryonic and yolk-sac larval period on the swimming performance of the later stages. |
Pham, Thuy Thi Thanh; Friðriksdóttir, Ragnhildur; Weber, Charlotte T; Viðarsson, Jónas R; Papandroulakis, Nikos; Baudron, Alan R; Olsen, Petter; Hansen, Juliana A; Laksá, Unn; Fernandes, Paul G; Bahri, Tarub; Ragnarsson, Sigurður Ö; Aschan, Michaela Guidelines for co-creating climate adaptation plans for fisheries and aquaculture Journal Article Climatic Change, 164 (3-4), pp. 62, 2021, ISSN: 0165-0009, 1573-1480. @article{pham_guidelines_2021, title = {Guidelines for co-creating climate adaptation plans for fisheries and aquaculture}, author = {Thuy Thi Thanh Pham and Ragnhildur Friðriksdóttir and Charlotte T Weber and Jónas R Viðarsson and Nikos Papandroulakis and Alan R Baudron and Petter Olsen and Juliana A Hansen and Unn Laksá and Paul G Fernandes and Tarub Bahri and Sigurður Ö Ragnarsson and Michaela Aschan}, url = {http://link.springer.com/10.1007/s10584-021-03041-z https://imbbc.hcmr.gr/wp-content/uploads/2021/03/2021-Pham-Climatic-change-23.pdf}, doi = {10.1007/s10584-021-03041-z}, issn = {0165-0009, 1573-1480}, year = {2021}, date = {2021-02-01}, urldate = {2021-03-17}, journal = {Climatic Change}, volume = {164}, number = {3-4}, pages = {62}, abstract = {Abstract Climate change is having a significant impact on the biology and ecology of fish stocks and aquaculture species and will affect the productivity within seafood supply chains in the future. The challenges are further amplified when actors within the fisheries and aquaculture sectors have very different ideas and assumptions about climate change and what risks and opportunities they entail. In order to address the challenges of climate change, several countries have developed national adaptation plans. However, fisheries and aquaculture are rarely included in these plans, resulting in a general lack of documented adaptation strategies within these sectors in most countries. This paper introduces guidelines for the development of climate adaptation plans (CAPs) within fisheries and aquaculture, applying a co-creation approach that requires the participation of scientists, industry representatives, policymakers, and other relevant stakeholders. The objective is to provide a stepwise approach to facilitate and enable stakeholders to plan strategies toward climate adaptation. The guidelines are based on practical experience and include a three-step process: (1) assessment of risks and opportunities; (2) identification of adaptation measures, and (3) operationalization of CAPs. The three-step process is also part of a larger cycle, including implementation, monitoring, and evaluation, again generating iterative feedback loops over time. Lessons learned are discussed, and we highlight the advantages and challenges of developing CAPs. While the guidelines are designed for and tested within fisheries and aquaculture systems, the CAP approach is also employable for other natural resource-based systems.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Abstract Climate change is having a significant impact on the biology and ecology of fish stocks and aquaculture species and will affect the productivity within seafood supply chains in the future. The challenges are further amplified when actors within the fisheries and aquaculture sectors have very different ideas and assumptions about climate change and what risks and opportunities they entail. In order to address the challenges of climate change, several countries have developed national adaptation plans. However, fisheries and aquaculture are rarely included in these plans, resulting in a general lack of documented adaptation strategies within these sectors in most countries. This paper introduces guidelines for the development of climate adaptation plans (CAPs) within fisheries and aquaculture, applying a co-creation approach that requires the participation of scientists, industry representatives, policymakers, and other relevant stakeholders. The objective is to provide a stepwise approach to facilitate and enable stakeholders to plan strategies toward climate adaptation. The guidelines are based on practical experience and include a three-step process: (1) assessment of risks and opportunities; (2) identification of adaptation measures, and (3) operationalization of CAPs. The three-step process is also part of a larger cycle, including implementation, monitoring, and evaluation, again generating iterative feedback loops over time. Lessons learned are discussed, and we highlight the advantages and challenges of developing CAPs. While the guidelines are designed for and tested within fisheries and aquaculture systems, the CAP approach is also employable for other natural resource-based systems. |
Makridis, Pavlos; Kokou, Fotini; Bournakas, Christos; Papandroulakis, Nikos; Sarropoulou, Elena Microorganisms, 9 (1), pp. 128, 2021, ISSN: 2076-2607. @article{makridis_isolation_2021, title = {Isolation of Phaeobacter sp. from Larvae of Atlantic Bonito (Sarda sarda) in a Mesocosmos Unit, and Its Use for the Rearing of European Seabass Larvae (Dicentrarchus labrax L.)}, author = {Pavlos Makridis and Fotini Kokou and Christos Bournakas and Nikos Papandroulakis and Elena Sarropoulou}, url = {https://imbbc.hcmr.gr/wp-content/uploads/2021/02/2021_2-Makridis-MICROORGANISMS.pdf https://www.mdpi.com/2076-2607/9/1/128}, doi = {10.3390/microorganisms9010128}, issn = {2076-2607}, year = {2021}, date = {2021-01-01}, urldate = {2021-02-02}, journal = {Microorganisms}, volume = {9}, number = {1}, pages = {128}, abstract = {The target of this study was to use indigenous probiotic bacteria in the rearing of seabass larvae. A Phaeobacter sp. strain isolated from bonito yolk-sac larvae (Sarda sarda) and identified by amplification of 16S rDNA showed in vitro inhibition against Vibrio anguillarum. This Phaeobacter sp. strain was used in the rearing of seabass larvae (Dicentrarchus labrax L.) in a large-scale trial. The survival of seabass after 60 days of rearing and the specific growth rate at the late exponential growth phase were significantly higher in the treatment receiving probiotics (p textless 0.05). Microbial community richness as determined by denaturing gradient gel electrophoresis (DGGE) showed an increase in bacterial diversity with fish development. Changes associated with the administration of probiotics were observed 11 and 18 days after hatching but were not apparent after probiotic administration stopped. In a small challenge experiment, seabass larvae from probiotic treatment showed increased survival (p textless 0.05) after experimental infection with a mild pathogen (Vibrio harveyi). Overall, our results showed that the use of an indigenous probiotic strain had a beneficial impact on larval rearing in industry-like conditions.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The target of this study was to use indigenous probiotic bacteria in the rearing of seabass larvae. A Phaeobacter sp. strain isolated from bonito yolk-sac larvae (Sarda sarda) and identified by amplification of 16S rDNA showed in vitro inhibition against Vibrio anguillarum. This Phaeobacter sp. strain was used in the rearing of seabass larvae (Dicentrarchus labrax L.) in a large-scale trial. The survival of seabass after 60 days of rearing and the specific growth rate at the late exponential growth phase were significantly higher in the treatment receiving probiotics (p textless 0.05). Microbial community richness as determined by denaturing gradient gel electrophoresis (DGGE) showed an increase in bacterial diversity with fish development. Changes associated with the administration of probiotics were observed 11 and 18 days after hatching but were not apparent after probiotic administration stopped. In a small challenge experiment, seabass larvae from probiotic treatment showed increased survival (p textless 0.05) after experimental infection with a mild pathogen (Vibrio harveyi). Overall, our results showed that the use of an indigenous probiotic strain had a beneficial impact on larval rearing in industry-like conditions. |
Chatziantoniou, Andromachi; Karagaitanakis, Alexandros; Bakopoulos, Vasileios; Papandroulakis, Nikos; Topouzelis, Konstantinos Detection of Biogenic Oil Films near Aquaculture Sites Using Sentinel-1 and Sentinel-2 Satellite Images Journal Article Remote Sensing, 13 (9), pp. 1737, 2021. @article{chatziantoniou_detection_2021, title = {Detection of Biogenic Oil Films near Aquaculture Sites Using Sentinel-1 and Sentinel-2 Satellite Images}, author = {Andromachi Chatziantoniou and Alexandros Karagaitanakis and Vasileios Bakopoulos and Nikos Papandroulakis and Konstantinos Topouzelis}, url = {https://www.mdpi.com/2072-4292/13/9/1737 https://imbbc.hcmr.gr/wp-content/uploads/2021/05/2021-Chatziantoniou-RemoteSensing-36.pdf}, doi = {10.3390/rs13091737}, year = {2021}, date = {2021-01-01}, urldate = {2021-05-10}, journal = {Remote Sensing}, volume = {13}, number = {9}, pages = {1737}, abstract = {Biogenic films are very thin surface oils, frequently observed near aquaculture farms, that affect the roughness and the optical properties of the sea surface, making them visible in SAR and multispectral images. The purpose of this study is to investigate the potential of satellite SAR and multispectral sensors in the detection of biogenic oil films near aquaculture farms. Sentinel-1 SAR and Sentinel-2 multispectral data were exploited to detect the films around three aquaculture sites. The study is divided in three stages: (a) preprocessing, (b) main process and (c) accuracy assessment. The preprocessing stage includes subset, filtering, land masking and image corrections. The main process was similar for both datasets, using an adaptive thresholding method to identify dark formations, extract and classify them. Finally, the performance of the algorithm was evaluated based on the estimation of standard classification error statistics. The evaluation of the results was based on empirical photointerpretation and in situ photos. The results are successful and promising, with overall accuracy over 70%, while both sensors are proved to be effective in the detection, with Sentinel-1 SAR presenting slightly better accuracy (81%) than Sentinel-2 MSI (70%). There is no evidence of these films causing stress to the aquaculture farms or the surrounding environment; however, our knowledge on their presence, amount and dissolution is limited and further knowledge could contribute to efficient feeding management and fish welfare.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Biogenic films are very thin surface oils, frequently observed near aquaculture farms, that affect the roughness and the optical properties of the sea surface, making them visible in SAR and multispectral images. The purpose of this study is to investigate the potential of satellite SAR and multispectral sensors in the detection of biogenic oil films near aquaculture farms. Sentinel-1 SAR and Sentinel-2 multispectral data were exploited to detect the films around three aquaculture sites. The study is divided in three stages: (a) preprocessing, (b) main process and (c) accuracy assessment. The preprocessing stage includes subset, filtering, land masking and image corrections. The main process was similar for both datasets, using an adaptive thresholding method to identify dark formations, extract and classify them. Finally, the performance of the algorithm was evaluated based on the estimation of standard classification error statistics. The evaluation of the results was based on empirical photointerpretation and in situ photos. The results are successful and promising, with overall accuracy over 70%, while both sensors are proved to be effective in the detection, with Sentinel-1 SAR presenting slightly better accuracy (81%) than Sentinel-2 MSI (70%). There is no evidence of these films causing stress to the aquaculture farms or the surrounding environment; however, our knowledge on their presence, amount and dissolution is limited and further knowledge could contribute to efficient feeding management and fish welfare. |
Stavrakidis-Zachou, Orestis; Lika, Konstadia; Anastasiadis, Panagiotis; Papandroulakis, Nikos Projecting climate change impacts on Mediterranean finfish production: a case study in Greece Journal Article Climatic Change, 165 (3), pp. 67, 2021, ISSN: 1573-1480. @article{stavrakidis-zachou_projecting_2021, title = {Projecting climate change impacts on Mediterranean finfish production: a case study in Greece}, author = {Orestis Stavrakidis-Zachou and Konstadia Lika and Panagiotis Anastasiadis and Nikos Papandroulakis}, url = {https://imbbc.hcmr.gr/wp-content/uploads/2021/06/2021-Stavrakidis-Zachou-Climate-Chnage-38.pdf https://doi.org/10.1007/s10584-021-03096-y}, doi = {10.1007/s10584-021-03096-y}, issn = {1573-1480}, year = {2021}, date = {2021-01-01}, urldate = {2021-06-24}, journal = {Climatic Change}, volume = {165}, number = {3}, pages = {67}, abstract = {Finfish aquaculture in the Mediterranean Sea faces increasing challenges due to climate change, while potential adaptation requires a robust assessment of the arising threats and opportunities. This paper presents an approach developed to investigate effects of climate drivers on Greek aquaculture, a representative Mediterranean country with a leading role in the sector. Using a farm level approach, dynamic energy budget models for European seabass and meagre were developed, and environmental forcing was used to simulate changes in production and farm profitability under IPCC scenarios RCP45 and RCP85. The effects of temperature and extreme weather events at the individual and farm levels were considered along with that of husbandry parameters such as stocking timing, market size, and farm location (inshore, offshore) for nine regions. The simulations suggest that at the individual level, fish may benefit from warmer temperatures in the future in terms of growth, thus reaching commercial sizes faster, while the husbandry parameters may have as large an effect on growth as the projected shifts in climatic cues. However, this benefit will be largely offset by the adverse effects of extreme weather events at the population level. Such events will be more frequent in the future and, depending on the intensity one assigns to them, they could cause losses in biomass and farm profits that range from mild to detrimental for the industry. Overall, these results provide quantification of some of the potential threats for an important aquaculture sector while suggesting possibilities to benefit from emerging opportunities. Therefore, they could contribute to improving the sector’s readiness for tackling important challenges in the future.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Finfish aquaculture in the Mediterranean Sea faces increasing challenges due to climate change, while potential adaptation requires a robust assessment of the arising threats and opportunities. This paper presents an approach developed to investigate effects of climate drivers on Greek aquaculture, a representative Mediterranean country with a leading role in the sector. Using a farm level approach, dynamic energy budget models for European seabass and meagre were developed, and environmental forcing was used to simulate changes in production and farm profitability under IPCC scenarios RCP45 and RCP85. The effects of temperature and extreme weather events at the individual and farm levels were considered along with that of husbandry parameters such as stocking timing, market size, and farm location (inshore, offshore) for nine regions. The simulations suggest that at the individual level, fish may benefit from warmer temperatures in the future in terms of growth, thus reaching commercial sizes faster, while the husbandry parameters may have as large an effect on growth as the projected shifts in climatic cues. However, this benefit will be largely offset by the adverse effects of extreme weather events at the population level. Such events will be more frequent in the future and, depending on the intensity one assigns to them, they could cause losses in biomass and farm profits that range from mild to detrimental for the industry. Overall, these results provide quantification of some of the potential threats for an important aquaculture sector while suggesting possibilities to benefit from emerging opportunities. Therefore, they could contribute to improving the sector’s readiness for tackling important challenges in the future. |
Stavrakidis-Zachou, Orestis; Sturm, Astrid; Lika, Konstadia; Wätzold, Frank; Papandroulakis, Nikos ClimeGreAq: A software-based DSS for the climate change adaptation of Greek aquaculture Journal Article Environmental Modelling & Software, 143 , pp. 105121, 2021, ISSN: 13648152. @article{stavrakidis-zachou_climegreaq_2021, title = {ClimeGreAq: A software-based DSS for the climate change adaptation of Greek aquaculture}, author = {Orestis Stavrakidis-Zachou and Astrid Sturm and Konstadia Lika and Frank Wätzold and Nikos Papandroulakis}, url = {https://imbbc.hcmr.gr/wp-content/uploads/2021/07/2021-Stavrakidis-EnvModSoft-56.pdf https://linkinghub.elsevier.com/retrieve/pii/S136481522100164X}, doi = {10.1016/j.envsoft.2021.105121}, issn = {13648152}, year = {2021}, date = {2021-01-01}, urldate = {2021-07-26}, journal = {Environmental Modelling & Software}, volume = {143}, pages = {105121}, keywords = {}, pubstate = {published}, tppubtype = {article} } |
Papadaki, Maria; Mandalakis, Manolis; Anastasiou, Thekla I; Pouli, Marina; Asderis, Michalis; Katharios, Pantelis; Papandroulakis, Nikos; Mylonas, Constantinos C Fish Physiology and Biochemistry, 47 (6), pp. 1777–1792, 2021, ISSN: 1573-5168. @article{papadaki_histological_2021, title = {Histological evaluation of sex differentiation and early sex identification in hatchery-produced greater amberjack (Seriola dumerili) reared in sea cages}, author = {Maria Papadaki and Manolis Mandalakis and Thekla I Anastasiou and Marina Pouli and Michalis Asderis and Pantelis Katharios and Nikos Papandroulakis and Constantinos C Mylonas}, url = {https://imbbc.hcmr.gr/wp-content/uploads/2021/12/2021-Papadaki-FFB-69-pre-print-1.pdf https://doi.org/10.1007/s10695-021-01007-7}, doi = {10.1007/s10695-021-01007-7}, issn = {1573-5168}, year = {2021}, date = {2021-01-01}, urldate = {2021-12-04}, journal = {Fish Physiology and Biochemistry}, volume = {47}, number = {6}, pages = {1777--1792}, abstract = {The histological process of gonadal differentiation, together with the endocrine changes of sex steroid hormones and some of their precursors, was studied in hatchery-produced greater amberjack Seriola dumerili from 101 until 408 days post-hatching (dph), with samplings conducted every 50 days. Histological processing showed that sex differentiation began at 101 dph with the formation of the ovarian cavity in females, while the presumptive males did not yet contain any germ cells in their gonad. At 150 dph, we observed the first germ cells in the developing testes. Sex differentiation in almost all sampled individuals was complete at 408 dph. No size dimorphism was observed between the sexes, and the sex ratio was 1:1, suggesting that there was no influence of early rearing in captivity on sex differentiation. Plasma concentrations of adrenosterone (Ad), androstenedione (Δ4), 11-ketotestosterone (11ΚΤ), testosterone (Τ), estradiol (Ε2), progesterone (P4) and 17,20β-dihydroxy-4-pregnen-3-one (17,20βP) were measured in males and females with the use of liquid chromatography tandem mass spectrometry (LC–MS/MS) to examine their role in the sex differentiation process. From the seven hormones, the only one that exhibited differences between the sexes was 11-KT and the plasma 11-KT concentration was found to be a useful indication of greater amberjack sex. Variations were observed in the mean values of Ad, Δ4, 11-KT, T, P4 and 17,20βP over time in one or both sexes, indicating their involvement in the sex differentiation process.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The histological process of gonadal differentiation, together with the endocrine changes of sex steroid hormones and some of their precursors, was studied in hatchery-produced greater amberjack Seriola dumerili from 101 until 408 days post-hatching (dph), with samplings conducted every 50 days. Histological processing showed that sex differentiation began at 101 dph with the formation of the ovarian cavity in females, while the presumptive males did not yet contain any germ cells in their gonad. At 150 dph, we observed the first germ cells in the developing testes. Sex differentiation in almost all sampled individuals was complete at 408 dph. No size dimorphism was observed between the sexes, and the sex ratio was 1:1, suggesting that there was no influence of early rearing in captivity on sex differentiation. Plasma concentrations of adrenosterone (Ad), androstenedione (Δ4), 11-ketotestosterone (11ΚΤ), testosterone (Τ), estradiol (Ε2), progesterone (P4) and 17,20β-dihydroxy-4-pregnen-3-one (17,20βP) were measured in males and females with the use of liquid chromatography tandem mass spectrometry (LC–MS/MS) to examine their role in the sex differentiation process. From the seven hormones, the only one that exhibited differences between the sexes was 11-KT and the plasma 11-KT concentration was found to be a useful indication of greater amberjack sex. Variations were observed in the mean values of Ad, Δ4, 11-KT, T, P4 and 17,20βP over time in one or both sexes, indicating their involvement in the sex differentiation process. |
Georgopoulou, Dimitra G; Stavrakidis-Zachou, Orestis; Mitrizakis, Nikos; Papandroulakis, Nikos Tracking and Analysis of the Movement Behavior of European Seabass (Dicentrarchus labrax) in Aquaculture Systems Journal Article Frontiers in Animal Science, 2 , pp. 79, 2021, ISSN: 2673-6225. @article{georgopoulou_tracking_2021, title = {Tracking and Analysis of the Movement Behavior of European Seabass (Dicentrarchus labrax) in Aquaculture Systems}, author = {Dimitra G Georgopoulou and Orestis Stavrakidis-Zachou and Nikos Mitrizakis and Nikos Papandroulakis}, url = {https://imbbc.hcmr.gr/wp-content/uploads/2022/01/2021-Georgopoulou-FrontAS-83.pdf https://www.frontiersin.org/article/10.3389/fanim.2021.754520}, doi = {10.3389/fanim.2021.754520}, issn = {2673-6225}, year = {2021}, date = {2021-01-01}, urldate = {2022-01-12}, journal = {Frontiers in Animal Science}, volume = {2}, pages = {79}, abstract = {Monitoring and understanding fish behavior is crucial for achieving precision in everyday husbandry practices (i.e. for optimizing farm performance), and for improving fish welfare in aquaculture. Various intelligent monitoring and control methods, using mathematical models, acoustic methods and computer vision, have been recently developed for this reason. Here, a tracking algorithm based on computer vision that extracts short trajectories of individual European seabass in both recirculating aquaculture systems and sea cages was developed using videos from network cameras. Using this methodology, parameters such as instantaneous normalized speed, travel direction and preference for the tank surface by European seabass could be quantified. When testing the sensitivity of this algorithm for detecting fish swimming variations under different husbandry scenarios, we found that the algorithm could detect variations in all of the abovementioned parameters and could potentially be a useful tool for monitoring the behavioral state of European seabass.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Monitoring and understanding fish behavior is crucial for achieving precision in everyday husbandry practices (i.e. for optimizing farm performance), and for improving fish welfare in aquaculture. Various intelligent monitoring and control methods, using mathematical models, acoustic methods and computer vision, have been recently developed for this reason. Here, a tracking algorithm based on computer vision that extracts short trajectories of individual European seabass in both recirculating aquaculture systems and sea cages was developed using videos from network cameras. Using this methodology, parameters such as instantaneous normalized speed, travel direction and preference for the tank surface by European seabass could be quantified. When testing the sensitivity of this algorithm for detecting fish swimming variations under different husbandry scenarios, we found that the algorithm could detect variations in all of the abovementioned parameters and could potentially be a useful tool for monitoring the behavioral state of European seabass. |
Zacheilas, Theofilos; Moirogiorgou, Konstantia; Papandroulakis, Nikos; Sotiriades, Euripides; Zervakis, Michalis; Dollas, Apostolos An FPGA-Based System for Video Processing to Detect Holes in Aquaculture Nets Inproceedings 2021 IEEE 21st International Conference on Bioinformatics and Bioengineering (BIBE), pp. 1–6, IEEE, Kragujevac, Serbia, 2021, ISBN: 9781665442619. @inproceedings{zacheilas_fpga-based_2021, title = {An FPGA-Based System for Video Processing to Detect Holes in Aquaculture Nets}, author = {Theofilos Zacheilas and Konstantia Moirogiorgou and Nikos Papandroulakis and Euripides Sotiriades and Michalis Zervakis and Apostolos Dollas}, url = {https://ieeexplore.ieee.org/document/9635351/}, doi = {10.1109/BIBE52308.2021.9635351}, isbn = {9781665442619}, year = {2021}, date = {2021-01-01}, urldate = {2022-02-28}, booktitle = {2021 IEEE 21st International Conference on Bioinformatics and Bioengineering (BIBE)}, pages = {1--6}, publisher = {IEEE}, address = {Kragujevac, Serbia}, keywords = {}, pubstate = {published}, tppubtype = {inproceedings} } |
Yildiz, Hijran Yavuzcan; Chatzifotis, Stavros; Anastasiadis, Panagiotis; Parisi, Giuliana; Papandroulakis, Nikos Testing of the Salmon Welfare Index Model (SWIM 1.0) as a computational welfare assessment for sea-caged European sea bass Journal Article Italian Journal of Animal Science, 20 (1), pp. 1423–1430, 2021, ISSN: null. @article{yavuzcan_yildiz_testing_2021, title = {Testing of the Salmon Welfare Index Model (SWIM 1.0) as a computational welfare assessment for sea-caged European sea bass}, author = {Hijran Yavuzcan Yildiz and Stavros Chatzifotis and Panagiotis Anastasiadis and Giuliana Parisi and Nikos Papandroulakis}, url = {https://doi.org/10.1080/1828051X.2021.1961106}, doi = {10.1080/1828051X.2021.1961106}, issn = {null}, year = {2021}, date = {2021-01-01}, urldate = {2022-02-28}, journal = {Italian Journal of Animal Science}, volume = {20}, number = {1}, pages = {1423--1430}, abstract = {The overall fish welfare in sea-caged European sea bass (Dicentrarchus labrax) was quantitatively assessed by adapting the Salmon Welfare Index Model (SWIM 1.0). In the model, a total of 16 operational welfare indicators in three segments (i) individual fish-based; (ii) fish-group specific; and (iii) sea cage environment-specific indicators were evaluated. In this study, the welfare indicators for salmon aquaculture which are incompatible with the characteristics of European sea bass were modified. Differently from SWIM 1.0, the welfare indicators of smoltification and salinity were eliminated; however, gill integrity and pH were added in the modified model of this study while the water temperature attributes were also changed in the model proposed. The modified model was tested for two sea cage farms of European sea bass (Farm A and Farm B) in two different locations of Mediterranean Sea for the first time. The overall welfare scores were expressed by a scale from 0-poor to 1-good welfare. The overall welfare assessment calculated by the model yielded the value of 1.0 and 0.81 for Farm A and Farm B, respectively. Based on the scores, Farm A represented the conditions of ‘good welfare’ while Farm B gave fair warning about welfare status. The methodology developed in the SWIM 1.0 model can be applied to European sea bass in Mediterranean aquaculture with small modifications.HIGHLIGHTSSalmon Welfare Index Model (SWIM 1.0) was utilised for E. sea bass welfare evaluationSWIM 1.0 was tested in sea-caged fish from two farms located in Mediterranean SeaSWIM 1.0 model can be applied to E. sea bass with small modifications}, keywords = {}, pubstate = {published}, tppubtype = {article} } The overall fish welfare in sea-caged European sea bass (Dicentrarchus labrax) was quantitatively assessed by adapting the Salmon Welfare Index Model (SWIM 1.0). In the model, a total of 16 operational welfare indicators in three segments (i) individual fish-based; (ii) fish-group specific; and (iii) sea cage environment-specific indicators were evaluated. In this study, the welfare indicators for salmon aquaculture which are incompatible with the characteristics of European sea bass were modified. Differently from SWIM 1.0, the welfare indicators of smoltification and salinity were eliminated; however, gill integrity and pH were added in the modified model of this study while the water temperature attributes were also changed in the model proposed. The modified model was tested for two sea cage farms of European sea bass (Farm A and Farm B) in two different locations of Mediterranean Sea for the first time. The overall welfare scores were expressed by a scale from 0-poor to 1-good welfare. The overall welfare assessment calculated by the model yielded the value of 1.0 and 0.81 for Farm A and Farm B, respectively. Based on the scores, Farm A represented the conditions of ‘good welfare’ while Farm B gave fair warning about welfare status. The methodology developed in the SWIM 1.0 model can be applied to European sea bass in Mediterranean aquaculture with small modifications.HIGHLIGHTSSalmon Welfare Index Model (SWIM 1.0) was utilised for E. sea bass welfare evaluationSWIM 1.0 was tested in sea-caged fish from two farms located in Mediterranean SeaSWIM 1.0 model can be applied to E. sea bass with small modifications |
2020 |
Pérez, José A; Papadakis, Ioannis E; Papandroulakis, Nikos; Cruces, Lorenzo; Cotou, Efthimia; Gisbert, Enric; Lorenzo, Antonio; Mylonas, Constantinos C; Rodríguez, Covadonga Aquaculture Nutrition, pp. anu.13128, 2020, ISSN: 1353-5773, 1365-2095. @article{perez_ontogeny_2020, title = {The ontogeny of greater amberjack digestive and antioxidant defence systems under different rearing conditions: A histological and enzymatic approach}, author = {José A Pérez and Ioannis E Papadakis and Nikos Papandroulakis and Lorenzo Cruces and Efthimia Cotou and Enric Gisbert and Antonio Lorenzo and Constantinos C Mylonas and Covadonga Rodríguez}, url = {https://onlinelibrary.wiley.com/doi/10.1111/anu.13128}, doi = {10.1111/anu.13128}, issn = {1353-5773, 1365-2095}, year = {2020}, date = {2020-09-01}, urldate = {2020-10-05}, journal = {Aquaculture Nutrition}, pages = {anu.13128}, keywords = {}, pubstate = {published}, tppubtype = {article} } |
Chatziantoniou, Andromachi; Bakopoulos, Vasileios; Papandroulakis, Nikos; Topouzelis, Konstantinos Detection of biogenic oil film near aquaculture sites seen by Sentinel-2 multispectral images Inproceedings Bostater, Charles R; Neyt, Xavier; Viallefont-Robinet, Françoise (Ed.): Remote Sensing of the Ocean, Sea Ice, Coastal Waters, and Large Water Regions 2020, pp. 4, SPIE, Online Only, United Kingdom, 2020, ISBN: 978-1-5106-3871-6 978-1-5106-3872-3. @inproceedings{chatziantoniou_detection_2020, title = {Detection of biogenic oil film near aquaculture sites seen by Sentinel-2 multispectral images}, author = {Andromachi Chatziantoniou and Vasileios Bakopoulos and Nikos Papandroulakis and Konstantinos Topouzelis}, editor = {Charles R Bostater and Xavier Neyt and Françoise Viallefont-Robinet}, url = {https://www.spiedigitallibrary.org/conference-proceedings-of-spie/11529/2573455/Detection-of-biogenic-oil-film-near-aquaculture-sites-seen-by/10.1117/12.2573455.full}, doi = {10.1117/12.2573455}, isbn = {978-1-5106-3871-6 978-1-5106-3872-3}, year = {2020}, date = {2020-09-01}, urldate = {2020-10-05}, booktitle = {Remote Sensing of the Ocean, Sea Ice, Coastal Waters, and Large Water Regions 2020}, pages = {4}, publisher = {SPIE}, address = {Online Only, United Kingdom}, keywords = {}, pubstate = {published}, tppubtype = {inproceedings} } |
Paspalakis, Stavros; Moirogiorgou, Konstantia; Papandroulakis, Nikos; Giakos, George; Zervakis, Michalis Automated fish cage net inspection using image processing techniques Journal Article IET Image Processing, 14 (10), pp. 2028–2034, 2020, ISSN: 1751-9659, 1751-9667. @article{paspalakis_automated_2020, title = {Automated fish cage net inspection using image processing techniques}, author = {Stavros Paspalakis and Konstantia Moirogiorgou and Nikos Papandroulakis and George Giakos and Michalis Zervakis}, url = {https://digital-library.theiet.org/content/journals/10.1049/iet-ipr.2019.1667}, doi = {10.1049/iet-ipr.2019.1667}, issn = {1751-9659, 1751-9667}, year = {2020}, date = {2020-08-01}, urldate = {2020-08-06}, journal = {IET Image Processing}, volume = {14}, number = {10}, pages = {2028--2034}, keywords = {}, pubstate = {published}, tppubtype = {article} } |
Kandyliari, Aikaterini; Karavoltsos, Sotirios; Sakellari, Aikaterini; Anastasiadis, Panagiotis; Asderis, Michalis; Papandroulakis, Nikos; Kapsofefalou, Maria Human and Ecological Risk Assessment: An International Journal, 27 (4), pp. 1126–1146, 2020, ISSN: 1080-7039, 1549-7860. @article{kandyliari_trace_2021, title = {Trace metals in six fish by-products of two farmed fishes, the gilthead sea bream ( textitSparus aurata ) and the meager ( textitArgyrosomus regius ): Interactions with the environment and feed}, author = {Aikaterini Kandyliari and Sotirios Karavoltsos and Aikaterini Sakellari and Panagiotis Anastasiadis and Michalis Asderis and Nikos Papandroulakis and Maria Kapsofefalou}, url = {https://imbbc.hcmr.gr/wp-content/uploads/2024/02/2021-Kandryliari-HERA-92.pdf https://www.tandfonline.com/doi/full/10.1080/10807039.2020.1799188}, doi = {10.1080/10807039.2020.1799188}, issn = {1080-7039, 1549-7860}, year = {2020}, date = {2020-07-28}, urldate = {2024-02-06}, journal = {Human and Ecological Risk Assessment: An International Journal}, volume = {27}, number = {4}, pages = {1126--1146}, keywords = {}, pubstate = {published}, tppubtype = {article} } |
Kandyliari, Aikaterini; Mallouchos, Athanasios; Papandroulakis, Nikos; Golla, Jaya Prakash; Lam, TuKiet T; Sakellari, Aikaterini; Karavoltsos, Sotirios; Vasiliou, Vasilis; Kapsokefalou, Maria Nutrient Composition and Fatty Acid and Protein Profiles of Selected Fish By-Products Journal Article Foods, 9 (2), pp. 190, 2020, ISSN: 2304-8158. @article{kandyliari_nutrient_2020, title = {Nutrient Composition and Fatty Acid and Protein Profiles of Selected Fish By-Products}, author = {Aikaterini Kandyliari and Athanasios Mallouchos and Nikos Papandroulakis and Jaya Prakash Golla and TuKiet T Lam and Aikaterini Sakellari and Sotirios Karavoltsos and Vasilis Vasiliou and Maria Kapsokefalou}, url = {https://www.mdpi.com/2304-8158/9/2/190}, doi = {10.3390/foods9020190}, issn = {2304-8158}, year = {2020}, date = {2020-02-01}, urldate = {2020-08-26}, journal = {Foods}, volume = {9}, number = {2}, pages = {190}, abstract = {Processing of fish in aquaculture generates considerable amounts of by-products that remain underused and/or unexploited. We evaluated the nutritive content of fish by-products (head, gills, intestines, trimmings, bones, and skin) from meagre and gilthead sea bream fish species reared in Greece in order to estimate their nutritional value for future development of high added-value products. The proximate composition of the fish samples (total protein, total lipid, ash, moisture, and macro-element content) was determined using the Association of Official Analytical Chemists (AOAC) and International Organization for Standardization (ISO) official methods. The content of fatty acids was determined using capillary gas chromatography, and the protein profile was estimated employing scientific orbitrap mass spectrophotometer methodology. The nutrient composition of fish by-products presented fluctuations among the different by-products. Skin was the most significant protein source, trimmings and bones were high in calcium, and the head, intestines, and bones were a good source of lipids. The most abundant lipid acids found in by-products were oleic, palmitic, linoleic, and eicosenoic acids, whereas the most abundant proteins were adenosine triphosphate (ATP) synthase subunit epsilon, mitochondrial nicotinamide adenine dinucleotide (NADH) dehydrogenase, and mitochondrial cytochrome b-c1 complex subunit 8. These data suggest that by-products constitute valuable sources of nutrients and could therefore be exploited in accordance with the principles of a circular economy.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Processing of fish in aquaculture generates considerable amounts of by-products that remain underused and/or unexploited. We evaluated the nutritive content of fish by-products (head, gills, intestines, trimmings, bones, and skin) from meagre and gilthead sea bream fish species reared in Greece in order to estimate their nutritional value for future development of high added-value products. The proximate composition of the fish samples (total protein, total lipid, ash, moisture, and macro-element content) was determined using the Association of Official Analytical Chemists (AOAC) and International Organization for Standardization (ISO) official methods. The content of fatty acids was determined using capillary gas chromatography, and the protein profile was estimated employing scientific orbitrap mass spectrophotometer methodology. The nutrient composition of fish by-products presented fluctuations among the different by-products. Skin was the most significant protein source, trimmings and bones were high in calcium, and the head, intestines, and bones were a good source of lipids. The most abundant lipid acids found in by-products were oleic, palmitic, linoleic, and eicosenoic acids, whereas the most abundant proteins were adenosine triphosphate (ATP) synthase subunit epsilon, mitochondrial nicotinamide adenine dinucleotide (NADH) dehydrogenase, and mitochondrial cytochrome b-c1 complex subunit 8. These data suggest that by-products constitute valuable sources of nutrients and could therefore be exploited in accordance with the principles of a circular economy. |
Fakriadis, Ioannis; Sigelaki, Irini; Papadaki, Maria; Papandroulakis, Nikos; Raftopoulos, Anastasios; Tsakoniti, Kalliopi; Mylonas, Constantinos C Control of reproduction of greater amberjack Seriola dumerili reared in aquaculture facilities Journal Article Aquaculture, 519 , 2020, ISSN: 00448486, (Type: Journal Article). @article{fakriadis_control_2020, title = {Control of reproduction of greater amberjack Seriola dumerili reared in aquaculture facilities}, author = {Ioannis Fakriadis and Irini Sigelaki and Maria Papadaki and Nikos Papandroulakis and Anastasios Raftopoulos and Kalliopi Tsakoniti and Constantinos C Mylonas}, url = {https://pdf.sciencedirectassets.com/271224/1-s2.0-S0044848619X00186/1-s2.0-S0044848619326079/main.pdf?X-Amz-Security-Token=IQoJb3JpZ2luX2VjEPb%2F%2F%2F%2F%2F%2F%2F%2F%2F%2FwEaCXVzLWVhc3QtMSJGMEQCIEKiYyI3Ycqx63hZp9lWGRWcsYrKIYv1T3L%2FsVCZBXRLAiBT0R83WGN4OE%2BrF0Q2Iy1lEA1RMiC7UHkh9ziKtbtPFyq9Awie%2F%2F%2F%2F%2F%2F%2F%2F%2F%2F8BEAIaDDA1OTAwMzU0Njg2NSIM4gS7FIQr6cp11X0pKpED%2FgoocYExFYA%2FLlo%2FsWYyzGVglS%2F6nkMLmZ%2ByMzYN3rGpSS8JnjWll%2BVBi9%2BQFiROQwjuZa3a%2FSAaLIRpIrqFJha5oaFJ1uYLfF5jH%2F62tRXpLB7sJQIii2PJpKgyFJfvrf62rUnhlVgggKANKBLslRjOQC8OAM6eh7pVSbTEeL5L2u1qmbgrN9sofvTRJjUhHYH6khAKTlWIN9Ms%2Bh%2FOYQd4hTDsXfs%2FCLNjH1yWN8vg5BwKN2LzwxBg4GRzlAPYuHtntee5qvC66DnoixqeUW9OTaf0KEv%2BJzwpT%2BfYdAWgXADTRYyGrESV0DPkx1DtTDORWmCg3rcA%2B2uudNnFW9OTbzBVItC8f9kdRQFCebf%2B8oUZjaQmpd6%2F9JT5xdXN8nmLLSD4B9f7HP4U9JMaLZ2mn8tdIZKFXY4RDIy4GDSatfnMgb2XPIRgWuB2PVcXkSf5FZFJA0%2BJ%2BNmXPCeB%2Brw8JB7L5LUaBqTpvV1HsryDzFT1ldBoXdenkb%2BNqHmCOXfEy1ym7f%2F1nzvO3WzGaPowo8Lu8QU67AFeu9OlXRP%2B4WswxYSqWZm5HLdCiyyyTFj51GbkOMdIlPKhnTIAVKhItiILXu%2BV72DuKLFa6Oi1iniDXP8KMQsuMUWjfimxW%2BdiyAeYmLmZMp09D130PUxEC8%2FPLMEyv0fXQY5U1q%2FlsoZwTHIjrGSmzdX9AV1AlVjKx9p6qyJ4fvBE%2BYBdfStdOdO5NaTrkff5pVoEXP1prc2HPySs%2BQ%2F%2FewSGTNjeUJHZDoVDpd17GFYHLwhoEHbOGt54OFz4kAAaHRh3S60uJxwRA6gSMwO%2But3nF4rDdIJSmL3QNM%2BO%2FY%2FK%2FF1ZYvaprhEPdQ%3D%3D&X-Amz-Algorithm=AWS4-HMAC-SHA256&X-Amz-Date=20200206T064417Z&X-Amz-SignedHeaders=host&X-Amz-Expires=300&X-Amz-Credential=ASIAQ3PHCVTYU72A2J4J%2F20200206%2Fus-east-1%2Fs3%2Faws4_request&X-Amz-Signature=ea8ff719b68d48407c48376c1561efa9042ae1f7598e65d269d5ba562bbe8262&hash=a4e2bfffdc3a781228d030d4043afc6504ec3ebb0665612a27237bc5a0c78826&host=68042c943591013ac2b2430a89b270f6af2c76d8dfd086a07176afe7c76c2c61&pii=S0044848619326079&tid=spdf-0066909c-c2cd-42a5-964f-1088618050da&sid=9f8cc34964ace14eda7b5f0927495aa20829gxrqb&type=client}, doi = {10.1016/j.aquaculture.2019.734880}, issn = {00448486}, year = {2020}, date = {2020-01-01}, journal = {Aquaculture}, volume = {519}, note = {Type: Journal Article}, keywords = {}, pubstate = {published}, tppubtype = {article} } |
Kokou, Fotini; Bastias, Roberto; Kokkari, Konstantina; Katharios, Pantelis; Cotou, Efthimia; Seimenis, Nikos; Vasilakis, Manolis; Papandroulakis, Nikos; Henry, Morgane; Rigos, George Surplus of dietary micronutrients promotes antioxidant defense and improves fin erosions in European seabass (Dicentrarchus labrax) fry Journal Article Aquaculture, 523 , pp. 735224, 2020, ISSN: 0044-8486. @article{kokou_surplus_2020, title = {Surplus of dietary micronutrients promotes antioxidant defense and improves fin erosions in European seabass (Dicentrarchus labrax) fry}, author = {Fotini Kokou and Roberto Bastias and Konstantina Kokkari and Pantelis Katharios and Efthimia Cotou and Nikos Seimenis and Manolis Vasilakis and Nikos Papandroulakis and Morgane Henry and George Rigos}, url = {http://www.sciencedirect.com/science/article/pii/S0044848619330868}, doi = {https://doi.org/10.1016/j.aquaculture.2020.735224}, issn = {0044-8486}, year = {2020}, date = {2020-01-01}, journal = {Aquaculture}, volume = {523}, pages = {735224}, abstract = {Dietary micronutrient supplementation can serve as skin health promotor to prevent from natural infections and can be applied to decrease the use of antibacterial agents and their impact on the environment. Such supplementation has indicated anti-inflammatory and antioxidant properties in farmed fish. In this study, dietary supplementation of zinc, selenium, ascorbic acid and niacin, at levels 2 to 3-fold higher than recommended, was evaluated as a measure to promote skin health and antioxidant defense in European seabass, Dicentrarchus labrax, fry. For this purpose, fish survival, growth performance, fin and skin erosions as well as whole-fish antioxidant enzyme activity (catalase, selenium (Se)-independent and dependent glutathione peroxidase) were assessed. Moreover, bacterial load in the rearing water and skin mucus were evaluated to assess the potential of the dietary micronutrient mixture as a preventive from natural infections. A group fed with a diet including these micronutrients at recommended levels served as a control. Surplus of these micronutrients significantly reduced the percentage of fish with eroded fins, while also induced the activity of catalase and Se-dependent glutathione peroxidase. Fish growth and bacterial loads in the water and fish skin mucus were not affected, whereas no skin lesions were observed. Overall, a mineral- and vitamin-supplemented diet at levels higher than recommended seems to act as a promotor of skin health and prevent from fin erosions, potentially through an increase in the antioxidant defense system.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Dietary micronutrient supplementation can serve as skin health promotor to prevent from natural infections and can be applied to decrease the use of antibacterial agents and their impact on the environment. Such supplementation has indicated anti-inflammatory and antioxidant properties in farmed fish. In this study, dietary supplementation of zinc, selenium, ascorbic acid and niacin, at levels 2 to 3-fold higher than recommended, was evaluated as a measure to promote skin health and antioxidant defense in European seabass, Dicentrarchus labrax, fry. For this purpose, fish survival, growth performance, fin and skin erosions as well as whole-fish antioxidant enzyme activity (catalase, selenium (Se)-independent and dependent glutathione peroxidase) were assessed. Moreover, bacterial load in the rearing water and skin mucus were evaluated to assess the potential of the dietary micronutrient mixture as a preventive from natural infections. A group fed with a diet including these micronutrients at recommended levels served as a control. Surplus of these micronutrients significantly reduced the percentage of fish with eroded fins, while also induced the activity of catalase and Se-dependent glutathione peroxidase. Fish growth and bacterial loads in the water and fish skin mucus were not affected, whereas no skin lesions were observed. Overall, a mineral- and vitamin-supplemented diet at levels higher than recommended seems to act as a promotor of skin health and prevent from fin erosions, potentially through an increase in the antioxidant defense system. |
2019 |
Sarropoulou, Elena; Kaitetzidou, Elizabet; Papandroulakis, Nikos; Tsalafouta, Aleka; Pavlidis, Michalis Inventory of European Sea Bass (Dicentrarchus labrax) sncRNAs Vital During Early Teleost Development Journal Article Frontiers in Genetics, 10 , pp. 657, 2019, ISSN: 1664-8021. @article{sarropoulou_inventory_2019, title = {Inventory of European Sea Bass (Dicentrarchus labrax) sncRNAs Vital During Early Teleost Development}, author = {Elena Sarropoulou and Elizabet Kaitetzidou and Nikos Papandroulakis and Aleka Tsalafouta and Michalis Pavlidis}, url = {https://www.frontiersin.org/article/10.3389/fgene.2019.00657/full}, doi = {10.3389/fgene.2019.00657}, issn = {1664-8021}, year = {2019}, date = {2019-07-01}, urldate = {2020-08-21}, journal = {Frontiers in Genetics}, volume = {10}, pages = {657}, keywords = {}, pubstate = {published}, tppubtype = {article} } |
Pérez, Evaristo; Linares, Fátima; Villanueva, José Luis Rodríguez; Vilar, Antonio; Mylonas, Constantinos C; Fakriadis, Ioannis; Papadaki, Maria; Papandroulakis, Nikos; Papadakis, Ioannis; Robles, Rocío; Fauvel, Christian; Roo, Javier; Peleteiro, José Benito; Lluch, Nuria; Pazos, Gema; Méndez, Belén; Sigelaki, Irini; Gómez, Castora; Pérez, Montse; Álvarez-Blázquez, Blanca Wreckfish (Polyprion americanus). New Knowledge About Reproduction, Larval Husbandry, and Nutrition. Promise as a New Species for Aquaculture Journal Article Fishes, 4 (1), pp. 14, 2019, (Type: Journal Article). @article{perez_wreckfish_2019, title = {Wreckfish (Polyprion americanus). New Knowledge About Reproduction, Larval Husbandry, and Nutrition. Promise as a New Species for Aquaculture}, author = {Evaristo Pérez and Fátima Linares and José Luis Rodríguez Villanueva and Antonio Vilar and Constantinos C Mylonas and Ioannis Fakriadis and Maria Papadaki and Nikos Papandroulakis and Ioannis Papadakis and Rocío Robles and Christian Fauvel and Javier Roo and José Benito Peleteiro and Nuria Lluch and Gema Pazos and Belén Méndez and Irini Sigelaki and Castora Gómez and Montse Pérez and Blanca Álvarez-Blázquez}, year = {2019}, date = {2019-01-01}, journal = {Fishes}, volume = {4}, number = {1}, pages = {14}, note = {Type: Journal Article}, keywords = {}, pubstate = {published}, tppubtype = {article} } |
Estévez, Alicia; Papandroulakis, Nikos; Wille, Mathieu; Sorgeloos, Patrick Early Life Stages and Weaning Incollection Lembo, Giuseppe; Mente, Elena (Ed.): Organic Aquaculture, pp. 79–102, Springer International Publishing, Cham, 2019, ISBN: 978-3-030-05602-5 978-3-030-05603-2. @incollection{lembo_early_2019, title = {Early Life Stages and Weaning}, author = {Alicia Estévez and Nikos Papandroulakis and Mathieu Wille and Patrick Sorgeloos}, editor = {Giuseppe Lembo and Elena Mente}, url = {http://link.springer.com/10.1007/978-3-030-05603-2_5}, doi = {10.1007/978-3-030-05603-2_5}, isbn = {978-3-030-05602-5 978-3-030-05603-2}, year = {2019}, date = {2019-01-01}, urldate = {2022-02-17}, booktitle = {Organic Aquaculture}, pages = {79--102}, publisher = {Springer International Publishing}, address = {Cham}, keywords = {}, pubstate = {published}, tppubtype = {incollection} } |
2018 |
Livanos, George; Zervakis, Michalis; Chalkiadakis, Vaggelis; Moirogiorgou, Konstantia; Giakos, George; Papandroulakis, Nikos 2018 IEEE International Conference on Imaging Systems and Techniques (IST), pp. 1–6, IEEE, Krakow, 2018, ISBN: 978-1-5386-6628-9. @inproceedings{livanos_intelligent_2018, title = {Intelligent Navigation and Control of a Prototype Autonomous Underwater Vehicle for Automated Inspection of Aquaculture net pen cages}, author = {George Livanos and Michalis Zervakis and Vaggelis Chalkiadakis and Konstantia Moirogiorgou and George Giakos and Nikos Papandroulakis}, url = {https://ieeexplore.ieee.org/document/8577180/}, doi = {10.1109/IST.2018.8577180}, isbn = {978-1-5386-6628-9}, year = {2018}, date = {2018-10-01}, urldate = {2020-08-26}, booktitle = {2018 IEEE International Conference on Imaging Systems and Techniques (IST)}, pages = {1--6}, publisher = {IEEE}, address = {Krakow}, keywords = {}, pubstate = {published}, tppubtype = {inproceedings} } |
Tsakogiannis, Alexandros; Manousaki, Tereza; Lagnel, Jacques; Papanikolaou, Nikolaos; Papandroulakis, Nikos; Mylonas, Constantinos C; Tsigenopoulos, Costas S The gene toolkit implicated in functional sex in Sparidae hermaphrodites: inferences from comparative transcriptomics Journal Article Frontiers in Genetics, 9 , pp. 749, 2018, (Publisher: Frontiers). @article{tsakogiannis_gene_2018, title = {The gene toolkit implicated in functional sex in Sparidae hermaphrodites: inferences from comparative transcriptomics}, author = {Alexandros Tsakogiannis and Tereza Manousaki and Jacques Lagnel and Nikolaos Papanikolaou and Nikos Papandroulakis and Constantinos C Mylonas and Costas S Tsigenopoulos}, year = {2018}, date = {2018-01-01}, journal = {Frontiers in Genetics}, volume = {9}, pages = {749}, note = {Publisher: Frontiers}, keywords = {}, pubstate = {published}, tppubtype = {article} } |
Tsakogiannis, A; Manousaki, T; Lagnel, J; Sterioti, A; Pavlidis, M; Papandroulakis, N; Mylonas, CC; Tsigenopoulos, CS The transcriptomic signature of different sexes in two protogynous hermaphrodites: Insights into the molecular network underlying sex phenotype in fish Journal Article Scientific reports, 8 (1), pp. 3564, 2018, (Publisher: Nature Publishing Group). @article{tsakogiannis_transcriptomic_2018, title = {The transcriptomic signature of different sexes in two protogynous hermaphrodites: Insights into the molecular network underlying sex phenotype in fish}, author = {A Tsakogiannis and T Manousaki and J Lagnel and A Sterioti and M Pavlidis and N Papandroulakis and CC Mylonas and CS Tsigenopoulos}, year = {2018}, date = {2018-01-01}, journal = {Scientific reports}, volume = {8}, number = {1}, pages = {3564}, note = {Publisher: Nature Publishing Group}, keywords = {}, pubstate = {published}, tppubtype = {article} } |
Stavrakidis-Zachou, O; Papandroulakis, N; Lika, K A DEB model for European sea bass (Dicentrarchus labrax): Parameterisation and application in aquaculture Journal Article Journal of Sea Research, 2018, ISSN: 13851101, (Publisher: Elsevier B.V.). @article{stavrakidis-zachou_deb_2018, title = {A DEB model for European sea bass (Dicentrarchus labrax): Parameterisation and application in aquaculture}, author = {O Stavrakidis-Zachou and N Papandroulakis and K Lika}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85048271464&doi=10.1016%2fj.seares.2018.05.008&partnerID=40&md5=035d420f79ff92d901d84ce9e157326c}, doi = {10.1016/j.seares.2018.05.008}, issn = {13851101}, year = {2018}, date = {2018-01-01}, journal = {Journal of Sea Research}, abstract = {The framework provided by the Dynamic Energy Budget (DEB) theory allows the quantification of metabolic processes and the associated biological rates that are of interest for aquaculture, such as growth and feeding. The DEB parameters were estimated for farmed European sea bass (Dicentrarchus labrax), a species of major importance for the Mediterranean aquaculture, using zero- and uni-variate literature data and achieving an overall good fit. The obtained parameter set was used to validate the model on sites representatively covering the geographic distribution of the aquaculture activity in Greece via comparison of model predictions to observations. Inter-individual variability of farmed fish was introduced through: 1) an individual initial weight and 2) a factor that acts as an individual-specific multiplier for some of the model parameters and produces scatter in maximum size, and age and size at puberty. Growth of E. sea bass was adequately predicted by the model while feeding tended to be underestimated, particularly during the period following the summer months when warmer temperatures promote high growth rates. The results suggest robustness of the model since it is able to simulate growth and food intake in several independent aquaculture production units, using a common parameter set. The accuracy of growth predictions supports the applicability of the model in variable environmental conditions in the context of climate change. Reconstruction of the feeding history from growth data revealed variations in the scaled functional response (f), i.e., the feeding rate as fraction of maximum possible one of an individual of a given size, throughout the production cycle. However, model simulations with constant f result in reasonably good predictions for growth and feeding in variable environmental conditions. Tendency of the model to underestimate the feeding process revealed both model weaknesses associated with higher temperatures as well as irregularities in the feeding protocols applied at the farm level. Our work demonstrates the capacity and potential of DEB theory for further development of tools that contribute to the assessment and improvement of feeding practices in aquaculture. © 2018 Elsevier B.V.}, note = {Publisher: Elsevier B.V.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The framework provided by the Dynamic Energy Budget (DEB) theory allows the quantification of metabolic processes and the associated biological rates that are of interest for aquaculture, such as growth and feeding. The DEB parameters were estimated for farmed European sea bass (Dicentrarchus labrax), a species of major importance for the Mediterranean aquaculture, using zero- and uni-variate literature data and achieving an overall good fit. The obtained parameter set was used to validate the model on sites representatively covering the geographic distribution of the aquaculture activity in Greece via comparison of model predictions to observations. Inter-individual variability of farmed fish was introduced through: 1) an individual initial weight and 2) a factor that acts as an individual-specific multiplier for some of the model parameters and produces scatter in maximum size, and age and size at puberty. Growth of E. sea bass was adequately predicted by the model while feeding tended to be underestimated, particularly during the period following the summer months when warmer temperatures promote high growth rates. The results suggest robustness of the model since it is able to simulate growth and food intake in several independent aquaculture production units, using a common parameter set. The accuracy of growth predictions supports the applicability of the model in variable environmental conditions in the context of climate change. Reconstruction of the feeding history from growth data revealed variations in the scaled functional response (f), i.e., the feeding rate as fraction of maximum possible one of an individual of a given size, throughout the production cycle. However, model simulations with constant f result in reasonably good predictions for growth and feeding in variable environmental conditions. Tendency of the model to underestimate the feeding process revealed both model weaknesses associated with higher temperatures as well as irregularities in the feeding protocols applied at the farm level. Our work demonstrates the capacity and potential of DEB theory for further development of tools that contribute to the assessment and improvement of feeding practices in aquaculture. © 2018 Elsevier B.V. |
Tsalafouta, A; Sarropoulou, E; Papandroulakis, N; Pavlidis, M Marine Biotechnology, 20 (5), pp. 611–622, 2018, ISSN: 14362228, (Publisher: Springer New York LLC). @article{tsalafouta_characterization_2018, title = {Characterization and Expression Dynamics of Key Genes Involved in the Gilthead Sea Bream (Sparus aurata) Cortisol Stress Response during Early Ontogeny}, author = {A Tsalafouta and E Sarropoulou and N Papandroulakis and M Pavlidis}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85048276185&doi=10.1007%2fs10126-018-9833-5&partnerID=40&md5=806b6e065e80bbd391d7c165a62a1c5d}, doi = {10.1007/s10126-018-9833-5}, issn = {14362228}, year = {2018}, date = {2018-01-01}, journal = {Marine Biotechnology}, volume = {20}, number = {5}, pages = {611--622}, abstract = {The present study identified and characterized six key genes involved in the hypothalamic-pituitary-interrenal (HPI) axis of gilthead sea bream (Sparus aurata), a commercially important European aquaculture species. The key genes involved in the HPI axis for which gene structure and synteny analysis was carried out, comprised of two functional forms of glucocorticoid receptors (GR), as well as three forms of pro-opiomelanocortin (POMC) genes and one form of mineralocorticoid receptor (MR) gene. To explore their functional roles during development but also in the stress response, the expression profiles of gr1, gr2, mr, pomc_aI, pomc_aII, and pomc_β were examined during early ontogeny and after an acute stress challenge. The acute stress challenge was applied at the stage of full formation of all fins, where whole body cortisol was also measured. Both the cortisol and the molecular data implied that sea bream larvae at the stage of the full formation of all fins at 45 dph are capable of a response to stress of a similar profile as observed in adult fish. © 2018, Springer Science+Business Media, LLC, part of Springer Nature.}, note = {Publisher: Springer New York LLC}, keywords = {}, pubstate = {published}, tppubtype = {article} } The present study identified and characterized six key genes involved in the hypothalamic-pituitary-interrenal (HPI) axis of gilthead sea bream (Sparus aurata), a commercially important European aquaculture species. The key genes involved in the HPI axis for which gene structure and synteny analysis was carried out, comprised of two functional forms of glucocorticoid receptors (GR), as well as three forms of pro-opiomelanocortin (POMC) genes and one form of mineralocorticoid receptor (MR) gene. To explore their functional roles during development but also in the stress response, the expression profiles of gr1, gr2, mr, pomc_aI, pomc_aII, and pomc_β were examined during early ontogeny and after an acute stress challenge. The acute stress challenge was applied at the stage of full formation of all fins, where whole body cortisol was also measured. Both the cortisol and the molecular data implied that sea bream larvae at the stage of the full formation of all fins at 45 dph are capable of a response to stress of a similar profile as observed in adult fish. © 2018, Springer Science+Business Media, LLC, part of Springer Nature. |
Chalkiadakis, V; Papandroulakis, N; Livanos, G; Moirogiorgou, K; Giakos, G; Zervakis, M Designing a small-sized autonomous underwater vehicle architecture for regular periodic fish-cage net inspection Inproceedings IST 2017 - IEEE International Conference on Imaging Systems and Techniques, Proceedings, pp. 1–6, Institute of Electrical and Electronics Engineers Inc., 2018, ISBN: 978-1-5386-1620-8. @inproceedings{chalkiadakis_designing_2018, title = {Designing a small-sized autonomous underwater vehicle architecture for regular periodic fish-cage net inspection}, author = {V Chalkiadakis and N Papandroulakis and G Livanos and K Moirogiorgou and G Giakos and M Zervakis}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85049438158&doi=10.1109%2fIST.2017.8261525&partnerID=40&md5=bc6a8c9d36f9c3351156fa1052397bd1}, doi = {10.1109/IST.2017.8261525}, isbn = {978-1-5386-1620-8}, year = {2018}, date = {2018-01-01}, booktitle = {IST 2017 - IEEE International Conference on Imaging Systems and Techniques, Proceedings}, volume = {2018-January}, pages = {1--6}, publisher = {Institute of Electrical and Electronics Engineers Inc.}, abstract = {Fish-cage dysfunctionalities in aquaculture installations can trigger significant negative consequences in the operational costs. Fish escapes due to problems in the infrastructure or increased death rates as a result of the existing environmental conditions are just a few of the most common reasons. Therefore, frequent periodic inspection of fish-cage nets is required, which can become a very expensive task. Small sized, low-cost autonomous devices can offer a lower cost alternative solution, providing also more frequent inspection and efficient timely alarming capabilities. In this paper, the design and operational characteristics of a small-sized Autonomous Underwater Vehicle (AUV) architecture are presented, yielding to a powerful tool for regular periodic fish-cage net inspection in terms of net holes and fouling. The proposed AUV system consists of different sensing components and utilizes advanced optical recognition techniques to automatically navigate within the aquaculture installation and detect fish-cage nets dysfunctionalities. Preliminary results extracted under the testing procedure in real conditions indicate that the proposed framework can prove a cost-effective, flexible and operative solution to provide appropriate corrective measures in order to eliminate fish escapes and minimise related maintenance and repair costs in fish infrastructure. © 2017 IEEE.}, keywords = {}, pubstate = {published}, tppubtype = {inproceedings} } Fish-cage dysfunctionalities in aquaculture installations can trigger significant negative consequences in the operational costs. Fish escapes due to problems in the infrastructure or increased death rates as a result of the existing environmental conditions are just a few of the most common reasons. Therefore, frequent periodic inspection of fish-cage nets is required, which can become a very expensive task. Small sized, low-cost autonomous devices can offer a lower cost alternative solution, providing also more frequent inspection and efficient timely alarming capabilities. In this paper, the design and operational characteristics of a small-sized Autonomous Underwater Vehicle (AUV) architecture are presented, yielding to a powerful tool for regular periodic fish-cage net inspection in terms of net holes and fouling. The proposed AUV system consists of different sensing components and utilizes advanced optical recognition techniques to automatically navigate within the aquaculture installation and detect fish-cage nets dysfunctionalities. Preliminary results extracted under the testing procedure in real conditions indicate that the proposed framework can prove a cost-effective, flexible and operative solution to provide appropriate corrective measures in order to eliminate fish escapes and minimise related maintenance and repair costs in fish infrastructure. © 2017 IEEE. |
Tsagarakis, K; Nikolioudakis, N; Papandroulakis, N; Vassilopoulou, V; Machias, A Preliminary assessment of discards survival in a multi-species Mediterranean bottom trawl fishery Journal Article Journal of Applied Ichthyology, 34 (4), pp. 842–849, 2018, ISSN: 01758659, (Publisher: Blackwell Publishing Ltd). @article{tsagarakis_preliminary_2018, title = {Preliminary assessment of discards survival in a multi-species Mediterranean bottom trawl fishery}, author = {K Tsagarakis and N Nikolioudakis and N Papandroulakis and V Vassilopoulou and A Machias}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85044287064&doi=10.1111%2fjai.13691&partnerID=40&md5=343688d04a304205bf82df889009e96d}, doi = {10.1111/jai.13691}, issn = {01758659}, year = {2018}, date = {2018-01-01}, journal = {Journal of Applied Ichthyology}, volume = {34}, number = {4}, pages = {842--849}, abstract = {The EU Common Fisheries Policy (CFP) reform establishes a gradual landing obligation for stocks for which catch limits are set, and in the Mediterranean for species with Minimum Conservation Reference Size. However, the landing obligation will not apply for species with scientific evidence of high survival rates. Discards estimates usually assume that the whole discarded catch is dead or dies at sea. However, survival of individuals discarded at sea is substantial for several species. In the Mediterranean Sea, the information on this issue is very limited. The aim of this study is to perform a preliminary assessment of the short-term survival of discards in the multi-species bottom trawl fishery in the Eastern Ionian Sea, Greece. Experimental fishing was held in spring when no water column stratification was observed and in autumn when a seasonal thermocline was formed. The catch was sorted, the regularly discarded species/sizes were put in tanks and their survival was monitored in specific time intervals up to 72 hr. A seasonal effect was obvious with high mortality in autumn being attributed to high water temperatures. Survival was low or zero for most species, but was relatively high for certain species (e.g., annular seabream, Diplodus annularis (Linnaeus, 1758); European conger, Conger conger (Linnaeus, 1758); brown comber, Serranus hepatus (Linnaeus, 1758) among bony fishes) and broad taxonomic categories (elasmobranchs and most invertebrates) in spring or in both seasons. Poor survival was generally estimated for most species subject to the landing obligation (e.g., hake, Merluccius merluccius (Linnaeus, 1758)). The present study, even though preliminary, can be important for improving future works, for identifying species with high survival potential, and—to a lesser extent—for the implementation of the CFP. © 2018 Blackwell Verlag GmbH}, note = {Publisher: Blackwell Publishing Ltd}, keywords = {}, pubstate = {published}, tppubtype = {article} } The EU Common Fisheries Policy (CFP) reform establishes a gradual landing obligation for stocks for which catch limits are set, and in the Mediterranean for species with Minimum Conservation Reference Size. However, the landing obligation will not apply for species with scientific evidence of high survival rates. Discards estimates usually assume that the whole discarded catch is dead or dies at sea. However, survival of individuals discarded at sea is substantial for several species. In the Mediterranean Sea, the information on this issue is very limited. The aim of this study is to perform a preliminary assessment of the short-term survival of discards in the multi-species bottom trawl fishery in the Eastern Ionian Sea, Greece. Experimental fishing was held in spring when no water column stratification was observed and in autumn when a seasonal thermocline was formed. The catch was sorted, the regularly discarded species/sizes were put in tanks and their survival was monitored in specific time intervals up to 72 hr. A seasonal effect was obvious with high mortality in autumn being attributed to high water temperatures. Survival was low or zero for most species, but was relatively high for certain species (e.g., annular seabream, Diplodus annularis (Linnaeus, 1758); European conger, Conger conger (Linnaeus, 1758); brown comber, Serranus hepatus (Linnaeus, 1758) among bony fishes) and broad taxonomic categories (elasmobranchs and most invertebrates) in spring or in both seasons. Poor survival was generally estimated for most species subject to the landing obligation (e.g., hake, Merluccius merluccius (Linnaeus, 1758)). The present study, even though preliminary, can be important for improving future works, for identifying species with high survival potential, and—to a lesser extent—for the implementation of the CFP. © 2018 Blackwell Verlag GmbH |
Samaras, A; Santo, C E; Papandroulakis, N; Mitrizakis, N; Pavlidis, M; Höglund, E; Pelgrim, T N M; Zethof, J; Spanings, F A T; Vindas, M A; Ebbesson, L O E; Flik, G; Gorissen, M Allostatic load and stress physiology in European seabass (Dicentrarchus labrax L.) and gilthead seabream (Sparus aurata L.) Journal Article Frontiers in Endocrinology, 9 , 2018, ISSN: 16642392, (Publisher: Frontiers Media S.A.). @article{samaras_allostatic_2018, title = {Allostatic load and stress physiology in European seabass (Dicentrarchus labrax L.) and gilthead seabream (Sparus aurata L.)}, author = {A Samaras and C E Santo and N Papandroulakis and N Mitrizakis and M Pavlidis and E Höglund and T N M Pelgrim and J Zethof and F A T Spanings and M A Vindas and L O E Ebbesson and G Flik and M Gorissen}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85052204375&doi=10.3389%2ffendo.2018.00451&partnerID=40&md5=0029971a56b42d71f149780bf330f378}, doi = {10.3389/fendo.2018.00451}, issn = {16642392}, year = {2018}, date = {2018-01-01}, journal = {Frontiers in Endocrinology}, volume = {9}, abstract = {The present study aimed to compare effects of increasing chronic stress load on the stress response of European seabass (Dicentrarchus labrax) and gilthead seabream (Sparus aurata) to identify neuroendocrine functions that regulate this response. Fish were left undisturbed (controls) or exposed to three levels of chronic stress for 3 weeks and then subjected to an acute stress test (ACT). Chronic stress impeded growth and decreased feed consumption in seabass, not in seabream. In seabass basal cortisol levels are high and increase with stress load; the response to a subsequent ACT decreases with increasing (earlier) load. Basal cortisol levels in seabream increase with the stress load, whereas the ACT induced a similar response in all groups. In seabass and seabream plasma a-MSH levels and brain stem serotonergic activity and turnover were similar and not affected by chronic stress. Species-specific molecular neuro-regional differences were seen. In-situ hybridization analysis of the early immediate gene cfos in the preoptic area showed ACT-activation in seabream; in seabass the expression level was not affected by ACT and seems constitutively high. In seabream, expression levels of telencephalic crf, crfbp, gr1, and mr were downregulated; the seabass hypothalamic preoptic area showed increased expression of crf and gr1, and decreased expression of mr, and this increased the gr1/mr ratio considerably. We substantiate species-specific physiological differences to stress coping between seabream and seabass at an endocrine and neuroendocrine molecular level. Seabass appear less resilient to stress, which we conclude from high basal activities of stress-related parameters and poor, or absent, responses to ACT. This comparative study reveals important aquaculture, husbandry, and welfare implications for the rearing of these species. © 2018 Samaras, Espírito Santo, Papandroulakis, Mitrizakis, Pavlidis, Höglund, Pelgrim, Zethof, Spanings, Vindas, Ebbesson, Flik and Gorissen.}, note = {Publisher: Frontiers Media S.A.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The present study aimed to compare effects of increasing chronic stress load on the stress response of European seabass (Dicentrarchus labrax) and gilthead seabream (Sparus aurata) to identify neuroendocrine functions that regulate this response. Fish were left undisturbed (controls) or exposed to three levels of chronic stress for 3 weeks and then subjected to an acute stress test (ACT). Chronic stress impeded growth and decreased feed consumption in seabass, not in seabream. In seabass basal cortisol levels are high and increase with stress load; the response to a subsequent ACT decreases with increasing (earlier) load. Basal cortisol levels in seabream increase with the stress load, whereas the ACT induced a similar response in all groups. In seabass and seabream plasma a-MSH levels and brain stem serotonergic activity and turnover were similar and not affected by chronic stress. Species-specific molecular neuro-regional differences were seen. In-situ hybridization analysis of the early immediate gene cfos in the preoptic area showed ACT-activation in seabream; in seabass the expression level was not affected by ACT and seems constitutively high. In seabream, expression levels of telencephalic crf, crfbp, gr1, and mr were downregulated; the seabass hypothalamic preoptic area showed increased expression of crf and gr1, and decreased expression of mr, and this increased the gr1/mr ratio considerably. We substantiate species-specific physiological differences to stress coping between seabream and seabass at an endocrine and neuroendocrine molecular level. Seabass appear less resilient to stress, which we conclude from high basal activities of stress-related parameters and poor, or absent, responses to ACT. This comparative study reveals important aquaculture, husbandry, and welfare implications for the rearing of these species. © 2018 Samaras, Espírito Santo, Papandroulakis, Mitrizakis, Pavlidis, Höglund, Pelgrim, Zethof, Spanings, Vindas, Ebbesson, Flik and Gorissen. |
Vindas, M A; Fokos, S; Pavlidis, M; Höglund, E; Dionysopoulou, S; Ebbesson, L O E; Papandroulakis, N; Dermon, C R Early life stress induces long-term changes in limbic areas of a teleost fish: The role of catecholamine systems in stress coping Journal Article Scientific Reports, 8 (1), 2018, ISSN: 20452322, (Publisher: Nature Publishing Group). @article{vindas_early_2018, title = {Early life stress induces long-term changes in limbic areas of a teleost fish: The role of catecholamine systems in stress coping}, author = {M A Vindas and S Fokos and M Pavlidis and E Höglund and S Dionysopoulou and L O E Ebbesson and N Papandroulakis and C R Dermon}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85044994347&doi=10.1038%2fs41598-018-23950-x&partnerID=40&md5=a9948e3afdf5ded78f0adabdcfdc813b}, doi = {10.1038/s41598-018-23950-x}, issn = {20452322}, year = {2018}, date = {2018-01-01}, journal = {Scientific Reports}, volume = {8}, number = {1}, abstract = {Early life stress (ELS) shapes the way individuals cope with future situations. Animals use cognitive flexibility to cope with their ever-changing environment and this is mainly processed in forebrain areas. We investigated the performance of juvenile gilthead seabream, previously subjected to an ELS regime. ELS fish showed overall higher brain catecholaminergic (CA) signalling and lower brain derived neurotrophic factor (bdnf) and higher cfos expression in region-specific areas. All fish showed a normal cortisol and serotonergic response to acute stress. Brain dopaminergic activity and the expression of the α2Α adrenergic receptor were overall higher in the fish homologue to the lateral septum (Vv), suggesting that the Vv is important in CA system regulation. Interestingly, ELS prevented post-acute stress downregulation of the α2Α receptor in the amygdala homologue (Dm3). There was a lack of post-stress response in the β2 adrenergic receptor expression and a downregulation in bdnf in the Dm3 of ELS fish, which together indicate an allostatic overload in their stress coping ability. ELS fish showed higher neuronal activity (cfos) post-acute stress in the hippocampus homologue (Dlv) and the Dm3. Our results show clear long-term effects on limbic systems of seabream that may compromise their future coping ability to environmental challenges. © 2018 The Author(s).}, note = {Publisher: Nature Publishing Group}, keywords = {}, pubstate = {published}, tppubtype = {article} } Early life stress (ELS) shapes the way individuals cope with future situations. Animals use cognitive flexibility to cope with their ever-changing environment and this is mainly processed in forebrain areas. We investigated the performance of juvenile gilthead seabream, previously subjected to an ELS regime. ELS fish showed overall higher brain catecholaminergic (CA) signalling and lower brain derived neurotrophic factor (bdnf) and higher cfos expression in region-specific areas. All fish showed a normal cortisol and serotonergic response to acute stress. Brain dopaminergic activity and the expression of the α2Α adrenergic receptor were overall higher in the fish homologue to the lateral septum (Vv), suggesting that the Vv is important in CA system regulation. Interestingly, ELS prevented post-acute stress downregulation of the α2Α receptor in the amygdala homologue (Dm3). There was a lack of post-stress response in the β2 adrenergic receptor expression and a downregulation in bdnf in the Dm3 of ELS fish, which together indicate an allostatic overload in their stress coping ability. ELS fish showed higher neuronal activity (cfos) post-acute stress in the hippocampus homologue (Dlv) and the Dm3. Our results show clear long-term effects on limbic systems of seabream that may compromise their future coping ability to environmental challenges. © 2018 The Author(s). |
Samaras, A; Papandroulakis, N; Lika, K; Pavlidis, M Water temperature modifies the acute stress response of European sea bass, Dicentrarchus labrax L. (1758) Journal Article Journal of Thermal Biology, 78 , pp. 84–91, 2018, ISSN: 03064565, (Publisher: Elsevier Ltd). @article{samaras_water_2018, title = {Water temperature modifies the acute stress response of European sea bass, Dicentrarchus labrax L. (1758)}, author = {A Samaras and N Papandroulakis and K Lika and M Pavlidis}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85053762555&doi=10.1016%2fj.jtherbio.2018.09.006&partnerID=40&md5=8dba31c1e7ae6049832236f9596c2463}, doi = {10.1016/j.jtherbio.2018.09.006}, issn = {03064565}, year = {2018}, date = {2018-01-01}, journal = {Journal of Thermal Biology}, volume = {78}, pages = {84--91}, abstract = {The effects of water temperature (15, 20 and 25 °C) on the stress response of European sea bass, Dicentrarchus labrax, were studied. Blood and water samples were collected prior and at 0.5, 1, 2, 4 and 8 h post-stress for hormonal and biochemical analysis. Water temperature affected the resting concentrations of all stress indicators examined, as well as their response after stress, apart from lactate which response was unaffected by temperature. Cortisol showed the response with the highest outcome at 15 °C, and the fastest at 25 °C. Cortisol release rate in the water was also faster and of higher magnitude at higher temperatures. Glucose had both the fastest and higher in magnitude response at 25 °C, while lactate responded similarly in all temperatures tested. Finally, osmolality changed only at the highest temperature. These results suggest that temperature should be taken into consideration when evaluating the resting levels of stress indicators of European sea bass in laboratory, rearing and field conditions. Additionally, the present results show that temperature affects the stress response, suggesting that fish can differ in their susceptibility to stress depending on the acclimatization temperature. Moreover, it was shown that cortisol release rate in the water, a non-invasive stress indicator, can depict the effects of temperature on cortisol stress response. © 2018 Elsevier Ltd}, note = {Publisher: Elsevier Ltd}, keywords = {}, pubstate = {published}, tppubtype = {article} } The effects of water temperature (15, 20 and 25 °C) on the stress response of European sea bass, Dicentrarchus labrax, were studied. Blood and water samples were collected prior and at 0.5, 1, 2, 4 and 8 h post-stress for hormonal and biochemical analysis. Water temperature affected the resting concentrations of all stress indicators examined, as well as their response after stress, apart from lactate which response was unaffected by temperature. Cortisol showed the response with the highest outcome at 15 °C, and the fastest at 25 °C. Cortisol release rate in the water was also faster and of higher magnitude at higher temperatures. Glucose had both the fastest and higher in magnitude response at 25 °C, while lactate responded similarly in all temperatures tested. Finally, osmolality changed only at the highest temperature. These results suggest that temperature should be taken into consideration when evaluating the resting levels of stress indicators of European sea bass in laboratory, rearing and field conditions. Additionally, the present results show that temperature affects the stress response, suggesting that fish can differ in their susceptibility to stress depending on the acclimatization temperature. Moreover, it was shown that cortisol release rate in the water, a non-invasive stress indicator, can depict the effects of temperature on cortisol stress response. © 2018 Elsevier Ltd |
Stavrakidis-Zachou, O; Papandroulakis, Nikos; Sturm, Astrid; Anastasiadis, Panagiotis; Wätzold, Frank; Lika, Konstadia Towards a computer-based decision support system for aquaculture stakeholders in Greece in the context of climate change Journal Article International Journal of Sustainable Agricultural Management and Informatics, 4 (3/4), pp. 219, 2018, ISSN: 2054-5819, 2054-5827. @article{stavrakidis-zachou_towards_2018, title = {Towards a computer-based decision support system for aquaculture stakeholders in Greece in the context of climate change}, author = {O Stavrakidis-Zachou and Nikos Papandroulakis and Astrid Sturm and Panagiotis Anastasiadis and Frank Wätzold and Konstadia Lika}, url = {http://www.inderscience.com/link.php?id=99235}, doi = {10.1504/IJSAMI.2018.099235}, issn = {2054-5819, 2054-5827}, year = {2018}, date = {2018-01-01}, urldate = {2020-08-26}, journal = {International Journal of Sustainable Agricultural Management and Informatics}, volume = {4}, number = {3/4}, pages = {219}, keywords = {}, pubstate = {published}, tppubtype = {article} } |
2017 |
Fountoulaki, E; Grigorakis, K; Kounna, C; Rigos, G; Papandroulakis, N; Diakogeorgakis, J; Kokou, F Growth performance and product quality of meagre (Argyrosomus regius) fed diets of different protein/lipid levels at industrial scale Journal Article Italian Journal of Animal Science, 16 (4), pp. 685–694, 2017, ISSN: 15944077, (Publisher: Taylor and Francis Ltd.). @article{fountoulaki_growth_2017, title = {Growth performance and product quality of meagre (Argyrosomus regius) fed diets of different protein/lipid levels at industrial scale}, author = {E Fountoulaki and K Grigorakis and C Kounna and G Rigos and N Papandroulakis and J Diakogeorgakis and F Kokou}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85031429178&doi=10.1080%2f1828051X.2017.1305259&partnerID=40&md5=00a307713794256023244d2994240e65}, doi = {10.1080/1828051X.2017.1305259}, issn = {15944077}, year = {2017}, date = {2017-01-01}, journal = {Italian Journal of Animal Science}, volume = {16}, number = {4}, pages = {685--694}, abstract = {The rearing of meagre (Argyrosomus regius) up to commercial sizes, using diets of different protein/lipid ratios, was examined in two long-term trials. In the first 2 × 2 trial, four diets containing two protein (43% and 47%) and two lipid levels (15% and 20%) were evaluated in fish of 350 g initial weight. Fish were reared for 8 months in triplicate experimental cages, up to final weight of 900g. Growth performance showed that diets containing 43% protein were the most appropriate, as indicated by the better thermal growth coefficient (TGC): 0.70 and 0.71 (vs. 0.61 and 0.53 for 47/15 and 47/20 diets) and better daily growth index DGI: 0.91 and 1.00 (vs. 0.88 and 0.79 for 47/15 and 47/20, respectively). Liver fat did not differ among groups, but liver glycogen in the 43/15 dietary group was found to be significantly higher than the 47/20 (3.89% vs 1.88%). The histological examinations revealed a trend for increased lipid deposition when fish were fed high fat diets. Diets that performed best, namely 43/15 and 43/20, were used in a second trial conducted at a commercial fish farm. Fish weighing 520g were reared for 7 months up to 1100 g final weight. No significant differences were observed in the growth parameters examined. The feed conversion ratio was found to be better in the 43/20 diet compared to the 43/15 (1.58 vs. 1.68, respectively). The dietary fat levels significantly affected fillet fat content. However, such difference in nutritional content was not reflected in human-perceived sensory differences. © 2017 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group.}, note = {Publisher: Taylor and Francis Ltd.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The rearing of meagre (Argyrosomus regius) up to commercial sizes, using diets of different protein/lipid ratios, was examined in two long-term trials. In the first 2 × 2 trial, four diets containing two protein (43% and 47%) and two lipid levels (15% and 20%) were evaluated in fish of 350 g initial weight. Fish were reared for 8 months in triplicate experimental cages, up to final weight of 900g. Growth performance showed that diets containing 43% protein were the most appropriate, as indicated by the better thermal growth coefficient (TGC): 0.70 and 0.71 (vs. 0.61 and 0.53 for 47/15 and 47/20 diets) and better daily growth index DGI: 0.91 and 1.00 (vs. 0.88 and 0.79 for 47/15 and 47/20, respectively). Liver fat did not differ among groups, but liver glycogen in the 43/15 dietary group was found to be significantly higher than the 47/20 (3.89% vs 1.88%). The histological examinations revealed a trend for increased lipid deposition when fish were fed high fat diets. Diets that performed best, namely 43/15 and 43/20, were used in a second trial conducted at a commercial fish farm. Fish weighing 520g were reared for 7 months up to 1100 g final weight. No significant differences were observed in the growth parameters examined. The feed conversion ratio was found to be better in the 43/20 diet compared to the 43/15 (1.58 vs. 1.68, respectively). The dietary fat levels significantly affected fillet fat content. However, such difference in nutritional content was not reflected in human-perceived sensory differences. © 2017 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group. |
Sarropoulou, E; Sundaram, A Y M; Kaitetzidou, E; Kotoulas, G; Gilfillan, G D; Papandroulakis, N; Mylonas, C C; Magoulas, A Full genome survey and dynamics of gene expression in the greater amberjack Seriola dumerili Journal Article GigaScience, 6 (12), pp. 1–13, 2017, ISSN: 2047217X, (Publisher: Oxford University Press). @article{sarropoulou_full_2017, title = {Full genome survey and dynamics of gene expression in the greater amberjack Seriola dumerili}, author = {E Sarropoulou and A Y M Sundaram and E Kaitetzidou and G Kotoulas and G D Gilfillan and N Papandroulakis and C C Mylonas and A Magoulas}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85042364258&doi=10.1093%2fgigascience%2fgix108&partnerID=40&md5=fa6e269b1e6ff57a26c0c9c6efe45226}, doi = {10.1093/gigascience/gix108}, issn = {2047217X}, year = {2017}, date = {2017-01-01}, journal = {GigaScience}, volume = {6}, number = {12}, pages = {1--13}, abstract = {Background: Teleosts of the genus Seriola, commonly known as amberjacks, are of high commercial value in international markets due to their flesh quality and worldwide distribution. The Seriola species of interest to Mediterranean aquaculture is the greater amberjack (Seriola dumerili). This species holds great potential for the aquaculture industry, but in captivity, reproduction has proved to be challenging, and observed growth dysfunction hinders their domestication. Insights into molecular mechanisms may contribute to a better understanding of traits like growth and sex, but investigations to unravel the molecular background of amberjacks have begun only recently. Findings: Illumina HiSeq sequencing generated a high-coverage greater amberjack genome sequence comprising 45 909 scaffolds. Comparative mapping to the Japanese yellowtail (Seriola quinqueriadiata) and to the model species medaka (Oryzias latipes) allowed the generation of in silico groups. Additional gonad transcriptome sequencing identified sex-biased transcripts, including known sex-determining and differentiation genes. Investigation of the muscle transcriptome of slow-growing individuals showed that transcripts involved in oxygen and gas transport were differentially expressed compared with fast/normal-growing individuals. On the other hand, transcripts involved in muscle functions were found to be enriched in fast/normal-growing individuals. Conclusion: The present study provides the first insights into the molecular background of male and female amberjacks and of fast- and slow-growing fish. Therefore, valuable molecular resources have been generated in the form of a first draft genome and a reference transcriptome. Sex-biased genes, which may also have roles in sex determination or differentiation, and genes that may be responsible for slow growth are suggested. © The Author(s) 2017.}, note = {Publisher: Oxford University Press}, keywords = {}, pubstate = {published}, tppubtype = {article} } Background: Teleosts of the genus Seriola, commonly known as amberjacks, are of high commercial value in international markets due to their flesh quality and worldwide distribution. The Seriola species of interest to Mediterranean aquaculture is the greater amberjack (Seriola dumerili). This species holds great potential for the aquaculture industry, but in captivity, reproduction has proved to be challenging, and observed growth dysfunction hinders their domestication. Insights into molecular mechanisms may contribute to a better understanding of traits like growth and sex, but investigations to unravel the molecular background of amberjacks have begun only recently. Findings: Illumina HiSeq sequencing generated a high-coverage greater amberjack genome sequence comprising 45 909 scaffolds. Comparative mapping to the Japanese yellowtail (Seriola quinqueriadiata) and to the model species medaka (Oryzias latipes) allowed the generation of in silico groups. Additional gonad transcriptome sequencing identified sex-biased transcripts, including known sex-determining and differentiation genes. Investigation of the muscle transcriptome of slow-growing individuals showed that transcripts involved in oxygen and gas transport were differentially expressed compared with fast/normal-growing individuals. On the other hand, transcripts involved in muscle functions were found to be enriched in fast/normal-growing individuals. Conclusion: The present study provides the first insights into the molecular background of male and female amberjacks and of fast- and slow-growing fish. Therefore, valuable molecular resources have been generated in the form of a first draft genome and a reference transcriptome. Sex-biased genes, which may also have roles in sex determination or differentiation, and genes that may be responsible for slow growth are suggested. © The Author(s) 2017. |
Fokos, S; Pavlidis, M; Yiotis, T; Tsalafouta, A; Papandroulakis, N; Dermon, C R Early life low intensity stress experience modifies acute stress effects on juvenile brain cell proliferation of European sea bass (Đ. Labrax) Journal Article Behavioural Brain Research, 317 , pp. 109–121, 2017, ISSN: 01664328, (Publisher: Elsevier B.V.). @article{fokos_early_2017, title = {Early life low intensity stress experience modifies acute stress effects on juvenile brain cell proliferation of European sea bass (Đ. Labrax)}, author = {S Fokos and M Pavlidis and T Yiotis and A Tsalafouta and N Papandroulakis and C R Dermon}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84987923402&doi=10.1016%2fj.bbr.2016.09.026&partnerID=40&md5=aa3396de79c8d5913bd1a8d7d802f2fe}, doi = {10.1016/j.bbr.2016.09.026}, issn = {01664328}, year = {2017}, date = {2017-01-01}, journal = {Behavioural Brain Research}, volume = {317}, pages = {109--121}, abstract = {Early life adversity may be critical for the brain structural plasticity that in turn would influence juvenile behaviour. To address this, we questioned whether early life environment has an impact on stress responses latter in life, using European sea bass, Dicentrarchus labrax, as a model organism. Unpredictable chronic low intensity stress (UCLIS), using a variety of moderate intensity stressors, was applied during two early ontogenetic stages, flexion or formation all fins. At juvenile stage, fish were exposed to acute stress and plasma cortisol, brain mRNA expression of corticosteroid receptors’ genes (gr1, gr2, mr) and brain cell proliferation (using BrdU immunohistochemistry) were determined in experimental and matched controls. UCLIS treatment specifically decreased brain gr1 expression in juveniles, but had no effect on the juvenile brain cell proliferation pattern within the major neurogenic zones studied of dorsal (Dm, Dld) and ventral (Vv) telencephalic, preoptic (NPO) areas, periventricular tectum gray zone (PGZ) and valvula cerebellum (VCe). In contrast, exposure to acute stress induced significant plasma cortisol rise, decreases of cerebral cell proliferation in juveniles, not previously exposed to UCLIS, but no effect detected on the expression levels of gr1, gr2 and mr in all groups of different early life history. Interestingly, juveniles with UCLIS history showed modified responses to acute stress, attenuating acute stress-induced cell proliferation decreases, indicating a long-lasting effect of early life treatment. Taken together, early life mild stress experience influences an acute stress plasticity end-point, cerebral cell proliferation, independently of the stress-axis activation, possibly leading to more effective coping styles. © 2016 Elsevier B.V.}, note = {Publisher: Elsevier B.V.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Early life adversity may be critical for the brain structural plasticity that in turn would influence juvenile behaviour. To address this, we questioned whether early life environment has an impact on stress responses latter in life, using European sea bass, Dicentrarchus labrax, as a model organism. Unpredictable chronic low intensity stress (UCLIS), using a variety of moderate intensity stressors, was applied during two early ontogenetic stages, flexion or formation all fins. At juvenile stage, fish were exposed to acute stress and plasma cortisol, brain mRNA expression of corticosteroid receptors’ genes (gr1, gr2, mr) and brain cell proliferation (using BrdU immunohistochemistry) were determined in experimental and matched controls. UCLIS treatment specifically decreased brain gr1 expression in juveniles, but had no effect on the juvenile brain cell proliferation pattern within the major neurogenic zones studied of dorsal (Dm, Dld) and ventral (Vv) telencephalic, preoptic (NPO) areas, periventricular tectum gray zone (PGZ) and valvula cerebellum (VCe). In contrast, exposure to acute stress induced significant plasma cortisol rise, decreases of cerebral cell proliferation in juveniles, not previously exposed to UCLIS, but no effect detected on the expression levels of gr1, gr2 and mr in all groups of different early life history. Interestingly, juveniles with UCLIS history showed modified responses to acute stress, attenuating acute stress-induced cell proliferation decreases, indicating a long-lasting effect of early life treatment. Taken together, early life mild stress experience influences an acute stress plasticity end-point, cerebral cell proliferation, independently of the stress-axis activation, possibly leading to more effective coping styles. © 2016 Elsevier B.V. |
Samaras, A; Pavlidis, M; Lika, K; Theodoridi, A; Papandroulakis, N Scale matters: performance of European sea bass, Dicentrarchus labrax, L. (1758), reared in cages of different volumes Journal Article Aquaculture Research, 48 (3), pp. 990–1005, 2017, ISSN: 1355557X, (Publisher: Blackwell Publishing Ltd). @article{samaras_scale_2017, title = {Scale matters: performance of European sea bass, Dicentrarchus labrax, L. (1758), reared in cages of different volumes}, author = {A Samaras and M Pavlidis and K Lika and A Theodoridi and N Papandroulakis}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84947750310&doi=10.1111%2fare.12942&partnerID=40&md5=2915761518f62b6ff5268fcab101e1c3}, doi = {10.1111/are.12942}, issn = {1355557X}, year = {2017}, date = {2017-01-01}, journal = {Aquaculture Research}, volume = {48}, number = {3}, pages = {990--1005}, abstract = {The effects of rearing volume on on-growing European sea bass performance and stress parameters were investigated for the first time in a pilot aquaculture farm. Fish were held under the same initial stocking densities in triplicate net-pen cages of different sizes (1.4, 45 and 252 m3) for a period of 8 months. Results showed significant differences among the experimental groups in most parameters tested, with better performance in the two larger rearing volumes. In particular, growth rate showed a linear association with rearing volume, being 0.68 g day−1 for the large cage group, 0.56 g day−1 and 0.32 g day−1 for the medium and the small groups respectively. The feed conversion ratio and per cent survival (%) were also better in the large cage group. Fish reared in the small and medium-sized cages showed higher plasma cortisol concentrations than those reared in large cages, which showed low basal cortisol concentrations. Additionally, after an acute chasing stress challenge, fish in the large and small groups, but not the medium group, showed increased cortisol concentrations. Differences also occurred in the ratio of the expression of cortisol receptors, namely the mineralocorticoid (mr) and glucocorticoid receptors (gr). In specific, the ratio of mr to grmRNA expression in the liver was higher in fish reared in the small cages. These findings verify that experimental scale significantly affects experimental results and is a critical factor for the interpretation of results. © 2015 John Wiley & Sons Ltd}, note = {Publisher: Blackwell Publishing Ltd}, keywords = {}, pubstate = {published}, tppubtype = {article} } The effects of rearing volume on on-growing European sea bass performance and stress parameters were investigated for the first time in a pilot aquaculture farm. Fish were held under the same initial stocking densities in triplicate net-pen cages of different sizes (1.4, 45 and 252 m3) for a period of 8 months. Results showed significant differences among the experimental groups in most parameters tested, with better performance in the two larger rearing volumes. In particular, growth rate showed a linear association with rearing volume, being 0.68 g day−1 for the large cage group, 0.56 g day−1 and 0.32 g day−1 for the medium and the small groups respectively. The feed conversion ratio and per cent survival (%) were also better in the large cage group. Fish reared in the small and medium-sized cages showed higher plasma cortisol concentrations than those reared in large cages, which showed low basal cortisol concentrations. Additionally, after an acute chasing stress challenge, fish in the large and small groups, but not the medium group, showed increased cortisol concentrations. Differences also occurred in the ratio of the expression of cortisol receptors, namely the mineralocorticoid (mr) and glucocorticoid receptors (gr). In specific, the ratio of mr to grmRNA expression in the liver was higher in fish reared in the small cages. These findings verify that experimental scale significantly affects experimental results and is a critical factor for the interpretation of results. © 2015 John Wiley & Sons Ltd |
Tsalafouta, A; Gorissen, M; Pelgrim, T N M; Papandroulakis, N; Flik, G; Pavlidis, M α-MSH and melanocortin receptors at early ontogeny in European sea bass (Dicentrarchus labrax, L.) Journal Article Scientific Reports, 7 , 2017, ISSN: 20452322, (Publisher: Nature Publishing Group). @article{tsalafouta_-msh_2017, title = {α-MSH and melanocortin receptors at early ontogeny in European sea bass (Dicentrarchus labrax, L.)}, author = {A Tsalafouta and M Gorissen and T N M Pelgrim and N Papandroulakis and G Flik and M Pavlidis}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85017163658&doi=10.1038%2fsrep46075&partnerID=40&md5=72c8e110367b4f60286fb0138c80202e}, doi = {10.1038/srep46075}, issn = {20452322}, year = {2017}, date = {2017-01-01}, journal = {Scientific Reports}, volume = {7}, abstract = {Temporal patterns of whole-body α-MSH concentrations and of transcripts of melanocortin receptors during early development as well as the endocrine response (α-MSH, cortisol, MCR mRNAs) to stress at the end of the larval period were characterized in Dicentrarchus labrax. Immunohistochemistry showed α-MSH positive cells in the pituitary pars intermedia in all stages examined. As development proceeds, α-MSH content gradually increases; mRNA levels of mc2r and mc4r remain low until first feeding where peak values are observed. Mc1r expression was constant during development, pomc mRNA levels remain low until the stage of flexion after which a significant increase is observed. At the stage of the formation of all fins, whole-body cortisol and α-MSH concentrations responded with peak values at 2 h post stress. Additionally, the stress challenge resulted in elevated transcript levels of pomc, mc2r and mc4r but not in mc1r, with a pattern characterized by peak values at 1 h post stress and a strong correlation with whole body α-MSH concentrations was found. Our data provide for the first time a view on the importance of the α-MSH stress response in early development of European sea bass, an additional and relatively poorly understood signal involved in the stress response in teleosts. © 2017 The Author(s).}, note = {Publisher: Nature Publishing Group}, keywords = {}, pubstate = {published}, tppubtype = {article} } Temporal patterns of whole-body α-MSH concentrations and of transcripts of melanocortin receptors during early development as well as the endocrine response (α-MSH, cortisol, MCR mRNAs) to stress at the end of the larval period were characterized in Dicentrarchus labrax. Immunohistochemistry showed α-MSH positive cells in the pituitary pars intermedia in all stages examined. As development proceeds, α-MSH content gradually increases; mRNA levels of mc2r and mc4r remain low until first feeding where peak values are observed. Mc1r expression was constant during development, pomc mRNA levels remain low until the stage of flexion after which a significant increase is observed. At the stage of the formation of all fins, whole-body cortisol and α-MSH concentrations responded with peak values at 2 h post stress. Additionally, the stress challenge resulted in elevated transcript levels of pomc, mc2r and mc4r but not in mc1r, with a pattern characterized by peak values at 1 h post stress and a strong correlation with whole body α-MSH concentrations was found. Our data provide for the first time a view on the importance of the α-MSH stress response in early development of European sea bass, an additional and relatively poorly understood signal involved in the stress response in teleosts. © 2017 The Author(s). |
Papandroulakis, N; Thomsen, C; Mintenbeck, K; Mayorga, P; Hernández-Brito, J J The EU-Project “TROPOS” Incollection Aquaculture Perspective of Multi-Use Sites in the Open Ocean: The Untapped Potential for Marine Resources in the Anthropocene, pp. 355–374, Springer International Publishing, 2017, ISBN: 978-3-319-51159-7 978-3-319-51157-3, (Publication Title: Aquaculture Perspective of Multi-Use Sites in the Open Ocean: The Untapped Potential for Marine Resources in the Anthropocene). @incollection{papandroulakis_eu-project_2017, title = {The EU-Project “TROPOS”}, author = {N Papandroulakis and C Thomsen and K Mintenbeck and P Mayorga and J J Hernández-Brito}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85033330595&doi=10.1007%2f978-3-319-51159-7_12&partnerID=40&md5=83d359ed5dce1da69213772dfb86488f}, doi = {10.1007/978-3-319-51159-7_12}, isbn = {978-3-319-51159-7 978-3-319-51157-3}, year = {2017}, date = {2017-01-01}, booktitle = {Aquaculture Perspective of Multi-Use Sites in the Open Ocean: The Untapped Potential for Marine Resources in the Anthropocene}, pages = {355--374}, publisher = {Springer International Publishing}, abstract = {The global population is growing and the demand for food and energy is steadily increasing. Coastal space all over the world becomes increasingly limited and near-shore resources are often already heavily exploited. The use of offshore regions may provide new opportunities, but also involves major challenges such as the development of designs and technologies suitable for offshore condition. The floating TROPOS 'Green & Blue' modular multi-use platform concept introduced in this chapter is especially designed for offshore conditions and provides solutions for the problems and obstacles involved in "moving offshore". The Green & Blue platform concept integrates fish and algae aquaculture with a wind farm. The floating multi-use approach allows for platform operation in deep waters and the promotion of synergies such as joint logistics, shared infrastructure and services, thereby making the use of offshore resources viable and profitable. © The Author(s) 2017.}, note = {Publication Title: Aquaculture Perspective of Multi-Use Sites in the Open Ocean: The Untapped Potential for Marine Resources in the Anthropocene}, keywords = {}, pubstate = {published}, tppubtype = {incollection} } The global population is growing and the demand for food and energy is steadily increasing. Coastal space all over the world becomes increasingly limited and near-shore resources are often already heavily exploited. The use of offshore regions may provide new opportunities, but also involves major challenges such as the development of designs and technologies suitable for offshore condition. The floating TROPOS 'Green & Blue' modular multi-use platform concept introduced in this chapter is especially designed for offshore conditions and provides solutions for the problems and obstacles involved in "moving offshore". The Green & Blue platform concept integrates fish and algae aquaculture with a wind farm. The floating multi-use approach allows for platform operation in deep waters and the promotion of synergies such as joint logistics, shared infrastructure and services, thereby making the use of offshore resources viable and profitable. © The Author(s) 2017. |
2016 |
Sarropoulou, E; Tsalafouta, A; Sundaram, A Y M; Gilfillan, G D; Kotoulas, G; Papandroulakis, N; Pavlidis, M Transcriptomic changes in relation to early-life events in the gilthead sea bream (Sparus aurata) Journal Article BMC Genomics, 17 (1), 2016, ISSN: 14712164, (Publisher: BioMed Central Ltd.). @article{sarropoulou_transcriptomic_2016, title = {Transcriptomic changes in relation to early-life events in the gilthead sea bream (Sparus aurata)}, author = {E Sarropoulou and A Tsalafouta and A Y M Sundaram and G D Gilfillan and G Kotoulas and N Papandroulakis and M Pavlidis}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84984849269&doi=10.1186%2fs12864-016-2874-0&partnerID=40&md5=0cba8ed79f3200cb9be9e48551ecc2e7}, doi = {10.1186/s12864-016-2874-0}, issn = {14712164}, year = {2016}, date = {2016-01-01}, journal = {BMC Genomics}, volume = {17}, number = {1}, abstract = {Background: Teleosts are exposed to a broad range of external stimuli, which may be either of acute or chronic nature. The larval phase of certain fish species offer a unique opportunity to study the interactions between genes and environmental factors during early life. The present study investigates the effects of early-life events, applied at different time points of early ontogeny (first feeding, flexion and development of all fins; Phase 1) as well as on the subsequent juvenile stage after the application of an additional acute stressor (Phase 2) in the gilthead sea bream (Sparus aurata), a commercially important European aquaculture species. Animal performance, the cortisol response and gene expression patterns during early development as well as on the subsequent phases (juveniles) after the application of additional acute stressors were investigated. Results: Significant differences on fish performance were found only for juveniles exposed to early-life events at the phase of the formation of all fins. On the transcriptome level distinct expression patterns were obtained for larvae as well as for juveniles with the most divergent expression pattern found to be again at the phase of the development of all fins, which showed to have also an impact later on in the acute stress response of juveniles. Conclusions: The present study showed that applying an early-life protocol, characterized by the unpredictable, variable and moderate intensity of the applied stimuli provides a relative realistic model to evaluate the impact of daily aquaculture practices on fish performance. In addition, the power of investigating global gene expression patterns is shown, providing significant insights regarding the response of early-life events during development and as juveniles after the application of extra acute stressors. © 2016 The Author(s).}, note = {Publisher: BioMed Central Ltd.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Background: Teleosts are exposed to a broad range of external stimuli, which may be either of acute or chronic nature. The larval phase of certain fish species offer a unique opportunity to study the interactions between genes and environmental factors during early life. The present study investigates the effects of early-life events, applied at different time points of early ontogeny (first feeding, flexion and development of all fins; Phase 1) as well as on the subsequent juvenile stage after the application of an additional acute stressor (Phase 2) in the gilthead sea bream (Sparus aurata), a commercially important European aquaculture species. Animal performance, the cortisol response and gene expression patterns during early development as well as on the subsequent phases (juveniles) after the application of additional acute stressors were investigated. Results: Significant differences on fish performance were found only for juveniles exposed to early-life events at the phase of the formation of all fins. On the transcriptome level distinct expression patterns were obtained for larvae as well as for juveniles with the most divergent expression pattern found to be again at the phase of the development of all fins, which showed to have also an impact later on in the acute stress response of juveniles. Conclusions: The present study showed that applying an early-life protocol, characterized by the unpredictable, variable and moderate intensity of the applied stimuli provides a relative realistic model to evaluate the impact of daily aquaculture practices on fish performance. In addition, the power of investigating global gene expression patterns is shown, providing significant insights regarding the response of early-life events during development and as juveniles after the application of extra acute stressors. © 2016 The Author(s). |
Samaras, A; Papandroulakis, N; Costari, M; Pavlidis, M Aquaculture Research, 47 (11), pp. 3501–3515, 2016, ISSN: 1355557X, (Publisher: Blackwell Publishing Ltd). @article{samaras_stress_2016, title = {Stress and metabolic indicators in a relatively high (European sea bass, Dicentrarchus labrax) and a low (meagre, Argyrosomus regius) cortisol responsive species, in different water temperatures}, author = {A Samaras and N Papandroulakis and M Costari and M Pavlidis}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84930257426&doi=10.1111%2fare.12800&partnerID=40&md5=d03824c08e8a6786f3c642d561911786}, doi = {10.1111/are.12800}, issn = {1355557X}, year = {2016}, date = {2016-01-01}, journal = {Aquaculture Research}, volume = {47}, number = {11}, pages = {3501--3515}, abstract = {The aim of this study was to examine species-specific differences in pre- and post-stress concentrations of haematological, metabolic and hormonal parameters in two Mediterranean fish species, one with relatively high (European sea bass, Dicentrarchus labrax) and the other with low (meagre, Argyrosomus regius) basal and post-stress blood cortisol concentrations, in relation to different water temperatures. Fish were reared in net-pen sea cages and exposed to an identical acute stressor (crowding and chasing with a net for 5 min) in three different periods of the year. Results indicated that inter-specific differences occurred in most of the examined parameters. In addition, within each species, differences between sampling periods existed in plasma cortisol, glucose, osmolarity, blood pH and muscle glycogen concentration. Glucose, lactate and osmotic pressure showed a constant pattern of change, with maxima at half an hour post stress in both species, while cortisol, and blood and muscle pH, were significantly altered only in E. sea bass. No alterations were observed in liver and muscle glycogen concentrations in E. sea bass, while a significant reduction was evident only in the coldest temperature in meagre. It is concluded that there are important species-specific differences in the magnitude of hormonal and metabolic response to acute stress and that both basal and post-stress blood cortisol concentrations are affected by the sampling period. © 2015 John Wiley & Sons Ltd}, note = {Publisher: Blackwell Publishing Ltd}, keywords = {}, pubstate = {published}, tppubtype = {article} } The aim of this study was to examine species-specific differences in pre- and post-stress concentrations of haematological, metabolic and hormonal parameters in two Mediterranean fish species, one with relatively high (European sea bass, Dicentrarchus labrax) and the other with low (meagre, Argyrosomus regius) basal and post-stress blood cortisol concentrations, in relation to different water temperatures. Fish were reared in net-pen sea cages and exposed to an identical acute stressor (crowding and chasing with a net for 5 min) in three different periods of the year. Results indicated that inter-specific differences occurred in most of the examined parameters. In addition, within each species, differences between sampling periods existed in plasma cortisol, glucose, osmolarity, blood pH and muscle glycogen concentration. Glucose, lactate and osmotic pressure showed a constant pattern of change, with maxima at half an hour post stress in both species, while cortisol, and blood and muscle pH, were significantly altered only in E. sea bass. No alterations were observed in liver and muscle glycogen concentrations in E. sea bass, while a significant reduction was evident only in the coldest temperature in meagre. It is concluded that there are important species-specific differences in the magnitude of hormonal and metabolic response to acute stress and that both basal and post-stress blood cortisol concentrations are affected by the sampling period. © 2015 John Wiley & Sons Ltd |
Manousaki, Tereza; Tsakogiannis, Alexandros; Taggart, John B; Palaiokostas, Christos; Tsaparis, Dimitris; Lagnel, Jacques; Chatziplis, Dimitrios; Magoulas, Antonios; Papandroulakis, Nikos; Mylonas, Constantinos C; TSIGENOPOULOS, C S Exploring a nonmodel teleost genome through rad sequencing—linkage mapping in Common Pandora, Pagellus erythrinus and comparative genomic analysis Journal Article G3: Genes, genomes, genetics, 6 (3), pp. 509–519, 2016, (Publisher: G3: Genes, Genomes, Genetics). @article{manousaki_exploring_2016, title = {Exploring a nonmodel teleost genome through rad sequencing—linkage mapping in Common Pandora, Pagellus erythrinus and comparative genomic analysis}, author = {Tereza Manousaki and Alexandros Tsakogiannis and John B Taggart and Christos Palaiokostas and Dimitris Tsaparis and Jacques Lagnel and Dimitrios Chatziplis and Antonios Magoulas and Nikos Papandroulakis and Constantinos C Mylonas and C. S. TSIGENOPOULOS }, year = {2016}, date = {2016-01-01}, journal = {G3: Genes, genomes, genetics}, volume = {6}, number = {3}, pages = {509--519}, note = {Publisher: G3: Genes, Genomes, Genetics}, keywords = {}, pubstate = {published}, tppubtype = {article} } |
2015 |
Lika, K; Pavlidis, M; Mitrizakis, N; Samaras, A; Papandroulakis, N Do experimental units of different scale affect the biological performance of European sea bass Dicentrarchus labrax larvae? Journal Article Journal of Fish Biology, 86 (4), pp. 1271–1285, 2015, ISSN: 00221112, (Publisher: Blackwell Publishing Ltd). @article{lika_experimental_2015, title = {Do experimental units of different scale affect the biological performance of European sea bass Dicentrarchus labrax larvae?}, author = {K Lika and M Pavlidis and N Mitrizakis and A Samaras and N Papandroulakis}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84926299929&doi=10.1111%2fjfb.12636&partnerID=40&md5=5403c1ba5a13116f63509dba87aeda78}, doi = {10.1111/jfb.12636}, issn = {00221112}, year = {2015}, date = {2015-01-01}, journal = {Journal of Fish Biology}, volume = {86}, number = {4}, pages = {1271--1285}, abstract = {The effects of different tank volumes (2000, 500 and 40l) on European sea bass Dicentrarchus labrax larval rearing, relating to growth, survival, quality and stress variables, were investigated. A dynamic energy budget (DEB) model was used to analyse the results. The hydrodynamics of the tanks exhibited differences, with the water currents in the 2000l tanks to be almost one order of magnitude stronger than those in the 40l ones. Important differences in fish growth were observed between small and large tank-rearing volumes, with the smallest tank resulting in the slowest growth. Based on the DEB model analysis, growth differences were related to feeding rates, with growth in the smaller tank limited by food availability. Differences in survival rates were not statistically significant among the tank-rearing volumes. The quality evaluation of the fry (in terms of swimbladder, jaw and skeletal abnormalities) showed differences, with the smallest tank having the highest percentage of deformed individuals. This could be attributed to both the feeding variances and the hydrodynamics in the tanks. No differences were observed in terms of whole-body cortisol at the two developmental stages; flexion, and when the larvae body was fully covered by melanophores; when analysis was performed. This indicates that the allostatic load exerted on fish of different groups was similar and inside the fish-coping abilities range, in terms of the cortisol response axis. The selection of the experimental scale is of importance, especially when the results are to be transferred and applied on an industrial scale. © 2015 The Fisheries Society of the British Isles.}, note = {Publisher: Blackwell Publishing Ltd}, keywords = {}, pubstate = {published}, tppubtype = {article} } The effects of different tank volumes (2000, 500 and 40l) on European sea bass Dicentrarchus labrax larval rearing, relating to growth, survival, quality and stress variables, were investigated. A dynamic energy budget (DEB) model was used to analyse the results. The hydrodynamics of the tanks exhibited differences, with the water currents in the 2000l tanks to be almost one order of magnitude stronger than those in the 40l ones. Important differences in fish growth were observed between small and large tank-rearing volumes, with the smallest tank resulting in the slowest growth. Based on the DEB model analysis, growth differences were related to feeding rates, with growth in the smaller tank limited by food availability. Differences in survival rates were not statistically significant among the tank-rearing volumes. The quality evaluation of the fry (in terms of swimbladder, jaw and skeletal abnormalities) showed differences, with the smallest tank having the highest percentage of deformed individuals. This could be attributed to both the feeding variances and the hydrodynamics in the tanks. No differences were observed in terms of whole-body cortisol at the two developmental stages; flexion, and when the larvae body was fully covered by melanophores; when analysis was performed. This indicates that the allostatic load exerted on fish of different groups was similar and inside the fish-coping abilities range, in terms of the cortisol response axis. The selection of the experimental scale is of importance, especially when the results are to be transferred and applied on an industrial scale. © 2015 The Fisheries Society of the British Isles. |
Tsalafouta, A; Papandroulakis, N; Pavlidis, M Early life stress and effects at subsequent stages of development in European sea bass (Đ. labrax) Journal Article Aquaculture, 436 , pp. 27–33, 2015, ISSN: 00448486, (Publisher: Elsevier B.V.). @article{tsalafouta_early_2015, title = {Early life stress and effects at subsequent stages of development in European sea bass (Đ. labrax)}, author = {A Tsalafouta and N Papandroulakis and M Pavlidis}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84983096284&doi=10.1016%2fj.aquaculture.2014.10.042&partnerID=40&md5=b3ff03b9f549480a2e50b266f6752fac}, doi = {10.1016/j.aquaculture.2014.10.042}, issn = {00448486}, year = {2015}, date = {2015-01-01}, journal = {Aquaculture}, volume = {436}, pages = {27--33}, abstract = {To investigate the effects of exposure to long term chronic mild stressors during early development on larvae and juvenile performance and cortisol stress response, an unpredictable chronic low intensity stress (UCLIS) protocol was developed for the first time and evaluated in European sea bass, Dicentrarchus labrax. UCLIS protocol was based on the unpredictability, variety, frequency and moderate intensity of the applied stressors, providing a relatively realistic model of everyday aquaculture husbandry practices. UCLIS lasted for 14 consecutive days, starting at different phases of early ontogeny (first feeding, flexion and development of all fins). Evaluation was performed through the determination of water-born cortisol concentrations of the larvae rearing tanks at regular intervals, recording of mortality and measurements of growth performance. In addition, its effects on subsequent developmental phases were evaluated by measurement of growth characteristics and by the determination of plasma cortisol in juvenile fish, prior and 30min after the application of an acute stressor. Our data show that European sea bass larvae are sensitive to mild husbandry stimuli with consequences even at subsequent stages of development, with the stages of first feeding and all fins being the most critical, providing the necessity to reconsider common rearing practices. In particular, UCLIS application resulted in higher water cortisol release rates in all groups compared to the controls proved to be a reliable non-invasive indicator of stress even during early ontogeny. Performance of fish in terms of survival, total length and wet weight was also affected by the stress protocol, as larvae that had been exposed to UCLIS at the beginning of first feeding and the formation of all fins displayed worst performance compared to fish exposed to UCLIS at flexion and compared to the controls. Early life stress did not affect plasma cortisol levels of juveniles exposed to additional acute stressors. However, fish were very sensitive to common handling practice and in addition, significant higher plasma cortisol concentrations were found in juveniles exposed to UCLIS at the stages of first feeding and onwards to flexion and the formation of all fins and onwards to the development of melanophores, compared to the other two groups in accordance with the differences observed in growth rates. Concluding, our data show for the first time that common husbandry practices during early development have an impact both on larvae performance and at later stages of development, as life history affected growth and the stress response in juvenile fish. © 2014 Elsevier B.V.}, note = {Publisher: Elsevier B.V.}, keywords = {}, pubstate = {published}, tppubtype = {article} } To investigate the effects of exposure to long term chronic mild stressors during early development on larvae and juvenile performance and cortisol stress response, an unpredictable chronic low intensity stress (UCLIS) protocol was developed for the first time and evaluated in European sea bass, Dicentrarchus labrax. UCLIS protocol was based on the unpredictability, variety, frequency and moderate intensity of the applied stressors, providing a relatively realistic model of everyday aquaculture husbandry practices. UCLIS lasted for 14 consecutive days, starting at different phases of early ontogeny (first feeding, flexion and development of all fins). Evaluation was performed through the determination of water-born cortisol concentrations of the larvae rearing tanks at regular intervals, recording of mortality and measurements of growth performance. In addition, its effects on subsequent developmental phases were evaluated by measurement of growth characteristics and by the determination of plasma cortisol in juvenile fish, prior and 30min after the application of an acute stressor. Our data show that European sea bass larvae are sensitive to mild husbandry stimuli with consequences even at subsequent stages of development, with the stages of first feeding and all fins being the most critical, providing the necessity to reconsider common rearing practices. In particular, UCLIS application resulted in higher water cortisol release rates in all groups compared to the controls proved to be a reliable non-invasive indicator of stress even during early ontogeny. Performance of fish in terms of survival, total length and wet weight was also affected by the stress protocol, as larvae that had been exposed to UCLIS at the beginning of first feeding and the formation of all fins displayed worst performance compared to fish exposed to UCLIS at flexion and compared to the controls. Early life stress did not affect plasma cortisol levels of juveniles exposed to additional acute stressors. However, fish were very sensitive to common handling practice and in addition, significant higher plasma cortisol concentrations were found in juveniles exposed to UCLIS at the stages of first feeding and onwards to flexion and the formation of all fins and onwards to the development of melanophores, compared to the other two groups in accordance with the differences observed in growth rates. Concluding, our data show for the first time that common husbandry practices during early development have an impact both on larvae performance and at later stages of development, as life history affected growth and the stress response in juvenile fish. © 2014 Elsevier B.V. |
Mazurais, D; Covès, D; Papandroulakis, N; Ortega, A; Desbruyeres, E; Huelvan, C; Gall, Le M M; de la Gándara, F; Cahu, C L Aquaculture Research, 46 (10), pp. 2323–2331, 2015, ISSN: 1355557X, (Publisher: Blackwell Publishing Ltd). @article{mazurais_gene_2015, title = {Gene expression pattern of digestive and antioxidant enzymes during the larval development of reared Atlantic bluefin tuna (ABFT), Thunnus thynnus L.}, author = {D Mazurais and D Covès and N Papandroulakis and A Ortega and E Desbruyeres and C Huelvan and M M Le Gall and F de la Gándara and C L Cahu}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84940889750&doi=10.1111%2fare.12387&partnerID=40&md5=d3e824a2d5cbc5ca8650e2aece56afaa}, doi = {10.1111/are.12387}, issn = {1355557X}, year = {2015}, date = {2015-01-01}, journal = {Aquaculture Research}, volume = {46}, number = {10}, pages = {2323--2331}, abstract = {The aim of this study was to determine whether mortality observed during the larval development of reared bluefin tuna (Thunnus thynnus) could be related to improper expression profiles of key genes involved in digestive or antioxidant response capabilities. Tuna larvae were sampled at hatching, 2, 5, 10, 15 and 20 dph (days post hatching) for the relative quantification of transcripts encoded by genes involved in digestive [trypsinogen 1 (TRYP1), alpha-amylase (AMY), aminopeptidase N (ANPEP)] and antioxidant [catalase (CAT)] functions. The levels of expression of ANPEP related to the development and maturation of intestinal function increased from 5 to 20 dph. Furthermore, AMY and TRYP1 genes, which are pancreatic enzymes implicated in carbohydrate and peptide digestions exhibit a typical peak of expression at 5 and 15 dph respectively. The antioxidant enzyme, CAT, exhibited higher mRNA levels during the first stage of larval development. In conclusion, our investigation indicates that the expression of genes involved in digestive and antioxidant physiological processes followed typical patterns which could not explain high mortality rate observed during the first stage of larval development. © 2015 John Wiley & Sons Ltd.}, note = {Publisher: Blackwell Publishing Ltd}, keywords = {}, pubstate = {published}, tppubtype = {article} } The aim of this study was to determine whether mortality observed during the larval development of reared bluefin tuna (Thunnus thynnus) could be related to improper expression profiles of key genes involved in digestive or antioxidant response capabilities. Tuna larvae were sampled at hatching, 2, 5, 10, 15 and 20 dph (days post hatching) for the relative quantification of transcripts encoded by genes involved in digestive [trypsinogen 1 (TRYP1), alpha-amylase (AMY), aminopeptidase N (ANPEP)] and antioxidant [catalase (CAT)] functions. The levels of expression of ANPEP related to the development and maturation of intestinal function increased from 5 to 20 dph. Furthermore, AMY and TRYP1 genes, which are pancreatic enzymes implicated in carbohydrate and peptide digestions exhibit a typical peak of expression at 5 and 15 dph respectively. The antioxidant enzyme, CAT, exhibited higher mRNA levels during the first stage of larval development. In conclusion, our investigation indicates that the expression of genes involved in digestive and antioxidant physiological processes followed typical patterns which could not explain high mortality rate observed during the first stage of larval development. © 2015 John Wiley & Sons Ltd. |
2014 |
Fatira, E; Papandroulakis, N; Pavlidis, M Diel changes in plasma cortisol and effects of size and stress duration on the cortisol response in European sea bass (Dicentrarchus labrax) Journal Article Fish Physiology and Biochemistry, 40 (3), pp. 911–919, 2014, ISSN: 0920-1742, 1573-5168. @article{fatira_diel_2014, title = {Diel changes in plasma cortisol and effects of size and stress duration on the cortisol response in European sea bass (Dicentrarchus labrax)}, author = {E Fatira and N Papandroulakis and M Pavlidis}, url = {http://link.springer.com/10.1007/s10695-013-9896-1}, doi = {10.1007/s10695-013-9896-1}, issn = {0920-1742, 1573-5168}, year = {2014}, date = {2014-06-01}, urldate = {2020-08-08}, journal = {Fish Physiology and Biochemistry}, volume = {40}, number = {3}, pages = {911--919}, keywords = {}, pubstate = {published}, tppubtype = {article} } |
Manousaki, Tereza; Tsakogiannis, Alexandros; Lagnel, Jacques; Sarropoulou, Elena; Xiang, Jenny Z; Papandroulakis, Nikos; Mylonas, Constantinos C; Tsigenopoulos, Costas S The sex-specific transcriptome of the hermaphrodite sparid sharpsnout seabream (Diplodus puntazzo) Journal Article BMC genomics, 15 (1), pp. 655, 2014, (Publisher: BioMed Central). @article{manousaki_sex-specific_2014, title = {The sex-specific transcriptome of the hermaphrodite sparid sharpsnout seabream (Diplodus puntazzo)}, author = {Tereza Manousaki and Alexandros Tsakogiannis and Jacques Lagnel and Elena Sarropoulou and Jenny Z Xiang and Nikos Papandroulakis and Constantinos C Mylonas and Costas S Tsigenopoulos}, year = {2014}, date = {2014-01-01}, journal = {BMC genomics}, volume = {15}, number = {1}, pages = {655}, note = {Publisher: BioMed Central}, keywords = {}, pubstate = {published}, tppubtype = {article} } |
Tsalafouta, A; Papandroulakis, N; Gorissen, M; Katharios, P; Flik, G; Pavlidis, M Ontogenesis of the HPI axis and molecular regulation of the cortisol stress response during early development in Dicentrarchus labrax Journal Article Scientific Reports, 4 , 2014, ISSN: 20452322, (Publisher: Nature Publishing Group). @article{tsalafouta_ontogenesis_2014, title = {Ontogenesis of the HPI axis and molecular regulation of the cortisol stress response during early development in Dicentrarchus labrax}, author = {A Tsalafouta and N Papandroulakis and M Gorissen and P Katharios and G Flik and M Pavlidis}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84903781314&doi=10.1038%2fsrep05525&partnerID=40&md5=3f6318c0b65058abe75a45c284c78174}, doi = {10.1038/srep05525}, issn = {20452322}, year = {2014}, date = {2014-01-01}, journal = {Scientific Reports}, volume = {4}, abstract = {The cortisol stress response and the molecular programming of the corticoid axis were characterized for the first time during early ontogeny in a Mediterranean marine teleost, the European sea bass (Dicentrarchus labrax). Sea bass embryos, pre-larvae and larvae at specific points of development were exposed to acute stressors and the temporal patterns of cortisol whole body concentrations and the expression of genes involved in corticosteroid biosynthesis, degradation and signaling were determined. Expression of genes (gr1, gr2, mr, crf) involved into the corticoid response regulation combined with histological data indicated that, although a cortisol stress response is evident for the first time around first feeding, a pattern becomes established in larvae at flexion until the formation of all fins. Moreover, mRNA transcript levels of 11β 2-hydroxylase and 11β 2-hsd2 showed a strong correlation with the whole body cortisol concentrations. Concluding, our data reveal the presence of an adaptive mechanism in European sea bass at early ontogeny enabling to cope with external stressful stimuli and provide a better insight into the onset and regulation of the stress response in this species.}, note = {Publisher: Nature Publishing Group}, keywords = {}, pubstate = {published}, tppubtype = {article} } The cortisol stress response and the molecular programming of the corticoid axis were characterized for the first time during early ontogeny in a Mediterranean marine teleost, the European sea bass (Dicentrarchus labrax). Sea bass embryos, pre-larvae and larvae at specific points of development were exposed to acute stressors and the temporal patterns of cortisol whole body concentrations and the expression of genes involved in corticosteroid biosynthesis, degradation and signaling were determined. Expression of genes (gr1, gr2, mr, crf) involved into the corticoid response regulation combined with histological data indicated that, although a cortisol stress response is evident for the first time around first feeding, a pattern becomes established in larvae at flexion until the formation of all fins. Moreover, mRNA transcript levels of 11β 2-hydroxylase and 11β 2-hsd2 showed a strong correlation with the whole body cortisol concentrations. Concluding, our data reveal the presence of an adaptive mechanism in European sea bass at early ontogeny enabling to cope with external stressful stimuli and provide a better insight into the onset and regulation of the stress response in this species. |
Papandroulakis, N; Anastasiadis, P; Thomsen, C; Koutandos, E; Mayorga, P; Quevedo, E; Brito, J Modular multipurpose offshore platforms: Innovative opportunities for aquaculture Inproceedings pp. 955–956, Donostia-San Sebastian, Spain, 2014, (Publication Title: Aquaculture Europe-2014). @inproceedings{papandroulakis_modular_2014, title = {Modular multipurpose offshore platforms: Innovative opportunities for aquaculture}, author = {N Papandroulakis and P Anastasiadis and C Thomsen and E Koutandos and P Mayorga and E Quevedo and J Brito}, year = {2014}, date = {2014-01-01}, pages = {955--956}, address = {Donostia-San Sebastian, Spain}, note = {Publication Title: Aquaculture Europe-2014}, keywords = {}, pubstate = {published}, tppubtype = {inproceedings} } |
Sarropoulou, E; Moghadam, H K; Papandroulakis, N; de la Gandara, F; AO, Garcia; Makridis, P The Atlantic bonito (Sarda sarda, Bloch 1793) transcriptome and detection of differential expression during larvae development Journal Article PLoS ONE, 9 (2), pp. e87744, 2014. @article{sarropoulou_atlantic_2014, title = {The Atlantic bonito (Sarda sarda, Bloch 1793) transcriptome and detection of differential expression during larvae development}, author = {E Sarropoulou and H K Moghadam and N Papandroulakis and F de la Gandara and Garcia AO and P Makridis}, doi = {https://doi.org/10.1371/journal.pone.0087744}, year = {2014}, date = {2014-01-01}, journal = {PLoS ONE}, volume = {9}, number = {2}, pages = {e87744}, abstract = {The Atlantic bonito (Sarda sarda, Bloch 1793) belongs to the important marine fish species with a wide geographical distribution covering the Atlantic Ocean, the Mediterranean and its bordering seas. Aquaculture practices for this species are still in their infancies and scientific studies are seldom undertaken, mainly because of difficulties in sampling. Thus for small tuna species like the Atlantic bonito only little is known about its biology and regarding the molecular background even less information is available. In the production of marine fish it is known that the most critical period is the larval stages, as high growth rates as well as significant developmental changes take place. In this study we have investigated the transcriptome of the Atlantic bonito of five larvae stages applying Illumina sequencing technology. For non-model species like aquaculture species, transcriptome analysis of RNA samples from individuals using Illumina sequencing technology is technically efficient and cost effective. In the present study a total number of 169,326,711 paired-end reads with a read length of 100 base pairs were generated resulting in a reference transcriptome of 68,220 contigs with an average length of 2054 base pairs. For differential expression analyses single end reads were obtained from different developmental stages and mapped to the constructed reference transcriptome. Differential expression analyses revealed in total 18,657 differentially expressed transcripts and were assigned to five distinguished groups. Each of the five clusters shows stage specific gene expression. We present for the first time in the Atlantic bonito an extensive RNA-Seq based characterization of its transcriptome as well as significant information on differential expression among five developmental larvae stages. The generated transcripts, including SNP and microsatellite information for candidate molecular markers and gene expression information will be a valuable resource for future genetic and molecular studies.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The Atlantic bonito (Sarda sarda, Bloch 1793) belongs to the important marine fish species with a wide geographical distribution covering the Atlantic Ocean, the Mediterranean and its bordering seas. Aquaculture practices for this species are still in their infancies and scientific studies are seldom undertaken, mainly because of difficulties in sampling. Thus for small tuna species like the Atlantic bonito only little is known about its biology and regarding the molecular background even less information is available. In the production of marine fish it is known that the most critical period is the larval stages, as high growth rates as well as significant developmental changes take place. In this study we have investigated the transcriptome of the Atlantic bonito of five larvae stages applying Illumina sequencing technology. For non-model species like aquaculture species, transcriptome analysis of RNA samples from individuals using Illumina sequencing technology is technically efficient and cost effective. In the present study a total number of 169,326,711 paired-end reads with a read length of 100 base pairs were generated resulting in a reference transcriptome of 68,220 contigs with an average length of 2054 base pairs. For differential expression analyses single end reads were obtained from different developmental stages and mapped to the constructed reference transcriptome. Differential expression analyses revealed in total 18,657 differentially expressed transcripts and were assigned to five distinguished groups. Each of the five clusters shows stage specific gene expression. We present for the first time in the Atlantic bonito an extensive RNA-Seq based characterization of its transcriptome as well as significant information on differential expression among five developmental larvae stages. The generated transcripts, including SNP and microsatellite information for candidate molecular markers and gene expression information will be a valuable resource for future genetic and molecular studies. |
Lu, S -Y; Yu, J C S; Wesnigk, J; Delory, E; Quevedo, E; Hernández, J; Llinás, O; Golmen, L; Papandroulakis, N; Anastasiadis, P Environmental aspects of designing multi-purpose offshore platforms in the scope of the FP7 TROPOS Project Inproceedings OCEANS 2014 - TAIPEI, Institute of Electrical and Electronics Engineers Inc., 2014, ISBN: 978-1-4799-3646-5. @inproceedings{lu_environmental_2014, title = {Environmental aspects of designing multi-purpose offshore platforms in the scope of the FP7 TROPOS Project}, author = {S -Y Lu and J C S Yu and J Wesnigk and E Delory and E Quevedo and J Hernández and O Llinás and L Golmen and N Papandroulakis and P Anastasiadis}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84918522489&doi=10.1109%2fOCEANS-TAIPEI.2014.6964306&partnerID=40&md5=53dda4ec7f91e5aadda006075b50ec18}, doi = {10.1109/OCEANS-TAIPEI.2014.6964306}, isbn = {978-1-4799-3646-5}, year = {2014}, date = {2014-01-01}, booktitle = {OCEANS 2014 - TAIPEI}, publisher = {Institute of Electrical and Electronics Engineers Inc.}, abstract = {The objective of the FP7 funded TROPOS project is to design a modular multi-use platform for use in deep waters, with a focus on the Mediterranean, tropical and sub-tropical regions. In this paper, the related environmental aspects are considered, where both legal and technical issues are addressed. The multiple purpose platforms can enlarge the benefit from different functions, and reduce the environmental impacts through synergies among single impact as well. This proposed study demonstrates the impact assessment through multiple, integrated technologies. © 2014 IEEE.}, keywords = {}, pubstate = {published}, tppubtype = {inproceedings} } The objective of the FP7 funded TROPOS project is to design a modular multi-use platform for use in deep waters, with a focus on the Mediterranean, tropical and sub-tropical regions. In this paper, the related environmental aspects are considered, where both legal and technical issues are addressed. The multiple purpose platforms can enlarge the benefit from different functions, and reduce the environmental impacts through synergies among single impact as well. This proposed study demonstrates the impact assessment through multiple, integrated technologies. © 2014 IEEE. |
Papandroulakis, N; Lika, K; Kristiansen, T S; Oppedal, F; Divanach, P; Pavlidis, M Behaviour of European sea bass, Dicentrarchus labrax L., in cages - impact of early life rearing conditions and management Journal Article Aquaculture Research, 45 (9), pp. 1545–1558, 2014, ISSN: 1355557X, (Publisher: Blackwell Publishing Ltd). @article{papandroulakis_behaviour_2014, title = {Behaviour of European sea bass, Dicentrarchus labrax L., in cages - impact of early life rearing conditions and management}, author = {N Papandroulakis and K Lika and T S Kristiansen and F Oppedal and P Divanach and M Pavlidis}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84904957506&doi=10.1111%2fare.12103&partnerID=40&md5=2b75258c38f880692350144e12b4c676}, doi = {10.1111/are.12103}, issn = {1355557X}, year = {2014}, date = {2014-01-01}, journal = {Aquaculture Research}, volume = {45}, number = {9}, pages = {1545--1558}, abstract = {European sea bass, Dicentrarchus labrax L., groups reared under different conditions during larval stages (mesocosm and intensive rearing) were monitored during on-growing in sea cages until marketable size (350-400 g). Four caged groups were followed for a period of 17 months each at a pilot scale farm, where vertical distribution behaviour was monitored. This was performed while fish were under calm conditions, during feeding and when stress events occurred. Also during two specific periods: (i) spawning and (ii) high water temperature. Clear differences in the behavioural pattern of swimming depth, displacement and used space between the groups were observed. The individuals from the mesocosm rearing were more sensitive to human presence, showing stronger reactions (speed of displacement and vertical distribution). Most pronounced differences were observed during the 'extreme' warm period and the reproductive season. Within the seasons, European sea bass responded during feeding and stress showing a tendency to move deeper compared to calm conditions. The increased displacements were longer during feeding and stress. © 2012 John Wiley & Sons Ltd.}, note = {Publisher: Blackwell Publishing Ltd}, keywords = {}, pubstate = {published}, tppubtype = {article} } European sea bass, Dicentrarchus labrax L., groups reared under different conditions during larval stages (mesocosm and intensive rearing) were monitored during on-growing in sea cages until marketable size (350-400 g). Four caged groups were followed for a period of 17 months each at a pilot scale farm, where vertical distribution behaviour was monitored. This was performed while fish were under calm conditions, during feeding and when stress events occurred. Also during two specific periods: (i) spawning and (ii) high water temperature. Clear differences in the behavioural pattern of swimming depth, displacement and used space between the groups were observed. The individuals from the mesocosm rearing were more sensitive to human presence, showing stronger reactions (speed of displacement and vertical distribution). Most pronounced differences were observed during the 'extreme' warm period and the reproductive season. Within the seasons, European sea bass responded during feeding and stress showing a tendency to move deeper compared to calm conditions. The increased displacements were longer during feeding and stress. © 2012 John Wiley & Sons Ltd. |
Lika, K; Kooijman, S A L M; Papandroulakis, N Metabolic acceleration in Mediterranean Perciformes Journal Article Journal of Sea Research, 94 , pp. 37–46, 2014, ISSN: 13851101, (Publisher: Elsevier B.V.). @article{lika_metabolic_2014, title = {Metabolic acceleration in Mediterranean Perciformes}, author = {K Lika and S A L M Kooijman and N Papandroulakis}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84921325214&doi=10.1016%2fj.seares.2013.12.012&partnerID=40&md5=c3c29fdbd2e48c6de6f72f440d2cadd3}, doi = {10.1016/j.seares.2013.12.012}, issn = {13851101}, year = {2014}, date = {2014-01-01}, journal = {Journal of Sea Research}, volume = {94}, pages = {37--46}, abstract = {Larval stages are considered the most critical of fish development. During a very short period of time (2 to 3. months), larvae undergo major morphoanatomical and functional changes in order to transform into juveniles while remaining functioning (developing, eating, surviving). Depending on species and environmental conditions, patterns in larval development may vary. We study the patterns of larval development for nine fish species of Perciformes reared under aquaculture conditions and compare them in terms of species-specific parameters derived from DEB theory. We extended the standard DEB model to include metabolic acceleration during the larval period, where maximum specific assimilation and energy conductance increase with length between birth and metabolic metamorphosis. Metabolic acceleration has as a consequence that larvae initially grow slower than juveniles and adults. Our results indicate that the species with higher acceleration have lower growth rates at birth and they also suggest that metabolic acceleration is related to spawning season. High metabolic acceleration of demersal species is associated with summer-autumn spawning in the Mediterranean, where temperature is high and food availability is low. © 2013 Elsevier B.V.}, note = {Publisher: Elsevier B.V.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Larval stages are considered the most critical of fish development. During a very short period of time (2 to 3. months), larvae undergo major morphoanatomical and functional changes in order to transform into juveniles while remaining functioning (developing, eating, surviving). Depending on species and environmental conditions, patterns in larval development may vary. We study the patterns of larval development for nine fish species of Perciformes reared under aquaculture conditions and compare them in terms of species-specific parameters derived from DEB theory. We extended the standard DEB model to include metabolic acceleration during the larval period, where maximum specific assimilation and energy conductance increase with length between birth and metabolic metamorphosis. Metabolic acceleration has as a consequence that larvae initially grow slower than juveniles and adults. Our results indicate that the species with higher acceleration have lower growth rates at birth and they also suggest that metabolic acceleration is related to spawning season. High metabolic acceleration of demersal species is associated with summer-autumn spawning in the Mediterranean, where temperature is high and food availability is low. © 2013 Elsevier B.V. |
2013 |
Quevedo, E; Carton, M; Delory, E; Castro, A; Hernandez, J; Llinas, O; Lara, De J; Papandroulakis, N; Anastasiadis, P; Bard, J; Jeffrey, H; Ingram, D; Wesnigk, J Multi-use offshore platform configurations in the scope of the FP7 TROPOS Project Inproceedings OCEANS 2013 MTS/IEEE Bergen: The Challenges of the Northern Dimension, Bergen, Norway, 2013. @inproceedings{quevedo_multi-use_2013, title = {Multi-use offshore platform configurations in the scope of the FP7 TROPOS Project}, author = {E Quevedo and M Carton and E Delory and A Castro and J Hernandez and O Llinas and J De Lara and N Papandroulakis and P Anastasiadis and J Bard and H Jeffrey and D Ingram and J Wesnigk}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-84886439294&partnerID=40&md5=54c0c539eacf3e570cd2171b94fc0321}, year = {2013}, date = {2013-01-01}, booktitle = {OCEANS 2013 MTS/IEEE Bergen: The Challenges of the Northern Dimension}, address = {Bergen, Norway}, abstract = {The FP7 funded TROPOS project approach is to develop a modular multi-use platform for use in deep waters, with a focus on the Mediterranean, tropical and sub-tropical regions. In this paper, three different platforms configurations, - which have been designed to show the synergies and compatibilities among the platform uses of Transport, Energy, Aquaculture and Leisure - are presented. © 2013 IEEE.}, keywords = {}, pubstate = {published}, tppubtype = {inproceedings} } The FP7 funded TROPOS project approach is to develop a modular multi-use platform for use in deep waters, with a focus on the Mediterranean, tropical and sub-tropical regions. In this paper, three different platforms configurations, - which have been designed to show the synergies and compatibilities among the platform uses of Transport, Energy, Aquaculture and Leisure - are presented. © 2013 IEEE. |
Papandroulakis, N; Mesa-Rodriguez, A; Anastasiadis, P; Lisac, D; Asderis, M; Pavlidis, M Installation, operation and evaluation of a submerged cage at 45M depth in crete for the rearing of red porgy Pagrus pagrus Journal Article Aquaculture Research, 44 , pp. 1196 – 1205, 2013. @article{papandroulakis_installation_2013, title = {Installation, operation and evaluation of a submerged cage at 45M depth in crete for the rearing of red porgy Pagrus pagrus}, author = {N Papandroulakis and A Mesa-Rodriguez and P Anastasiadis and D Lisac and M Asderis and M Pavlidis}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-84880132630&partnerID=40&md5=23315b2563356028af8312af6d07c3c5}, year = {2013}, date = {2013-01-01}, journal = {Aquaculture Research}, volume = {44}, pages = {1196 -- 1205}, abstract = {Socio-economic factors related to management of costal zones and biological parameters related to species-specific requirements set limitations for the rearing location of net-pen sea cages. A cage was designed and installed at 45 m depth based on the REFA Tension Length Cage technology at the cage facility of the Hellenic Centre for Marine Research in Crete. The cage-net module consisted of a net-pen contained within a hexagonal rigid frame to maintain the shape of the net. Vertical beams of the frame glider on six tension legs were placed in a circle. The operation of the cage was evaluated using a group of red porgy (Pagrus pagrus) for a rearing period of 4 months whereas a second group reared in a surface net-pen cage served as control. Growth performance was similar between the experimental groups. The rearing method significantly affected fish skin pigmentation. Individuals reared in the submerged cage had a brighter skin colour and lower skin melatonin content compared with the ones reared in the surface cage. The presented submerged cage may provide a feasible alternative for rearing fish in exposed areas and particularly species requiring specific biological conditions, such as narrow temperature ranges and low light intensity. © 2012 John Wiley & Sons Ltd.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Socio-economic factors related to management of costal zones and biological parameters related to species-specific requirements set limitations for the rearing location of net-pen sea cages. A cage was designed and installed at 45 m depth based on the REFA Tension Length Cage technology at the cage facility of the Hellenic Centre for Marine Research in Crete. The cage-net module consisted of a net-pen contained within a hexagonal rigid frame to maintain the shape of the net. Vertical beams of the frame glider on six tension legs were placed in a circle. The operation of the cage was evaluated using a group of red porgy (Pagrus pagrus) for a rearing period of 4 months whereas a second group reared in a surface net-pen cage served as control. Growth performance was similar between the experimental groups. The rearing method significantly affected fish skin pigmentation. Individuals reared in the submerged cage had a brighter skin colour and lower skin melatonin content compared with the ones reared in the surface cage. The presented submerged cage may provide a feasible alternative for rearing fish in exposed areas and particularly species requiring specific biological conditions, such as narrow temperature ranges and low light intensity. © 2012 John Wiley & Sons Ltd. |
Makridis, P; Papandroulakis, N; Divanach, P Use of Phaeobacter sp. probiotic bacteria for the rearing of sea bass larvae (Dicentrarchus labrax). Journal Article Communications in agricultural and applied biological sciences, 78 (4), pp. 259–261, 2013, ISSN: 13791176. @article{makridis_use_2013, title = {Use of Phaeobacter sp. probiotic bacteria for the rearing of sea bass larvae (Dicentrarchus labrax).}, author = {P Makridis and N Papandroulakis and P Divanach}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84907261002&partnerID=40&md5=2d43cf01b17d910e6d0c1e4186e768bd}, issn = {13791176}, year = {2013}, date = {2013-01-01}, journal = {Communications in agricultural and applied biological sciences}, volume = {78}, number = {4}, pages = {259--261}, keywords = {}, pubstate = {published}, tppubtype = {article} } |
Gatesoupe, F -J; Covès, D; Ortega, A; Papandroulakis, N; Vadstein, O; de la Gándara, F Aquaculture Research, 44 , pp. 1511 – 1523, 2013. @article{gatesoupe_spatiotemporal_2013, title = {A spatiotemporal study of bacterial community profiles associated with atlantic bluefin tuna larvae, thunnus thynnus l., in three mediterranean hatcheries}, author = {F -J Gatesoupe and D Covès and A Ortega and N Papandroulakis and O Vadstein and F de la Gándara}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-84883561140&partnerID=40&md5=6f51e88136f163b5b20c3380b332a978}, year = {2013}, date = {2013-01-01}, journal = {Aquaculture Research}, volume = {44}, pages = {1511 -- 1523}, abstract = {During the first 2 years of larval rearing trials with Atlantic bluefin tuna, survival was a challenging issue. As bacterial colonization of the gut has been shown to play a key role for other species, we studied the profiles of the microbiota associated with individual larvae at different stages in three distant hatcheries. The Bacterial Community Profile (BCP) was quantified based on PCR-DGGE analyses of partial amplicons from 16S rDNA. Considerable individual variability in BCP was observed before onset of feeding, and the BCP did not show regular fluctuation during ontogenesis. Microalgae were added to the rearing tanks in two of the three hatcheries, but it was not possible to distinguish the effect of location from the effect of algal addition on BCP. In one hatchery, the larvae were reared either with algal addition or in mesocosm, but due to high individual variability, no significant difference in BCP was detected between the two groups. It was hypothesized that this variability was caused by differences in health, physiological status and developmental stage of the larvae. A practical conclusion from the study is the need to analyse a considerable number of individuals to reflect statistically significant differences between the microbial communities associated with rearing groups. © 2012 John Wiley & Sons Ltd.}, keywords = {}, pubstate = {published}, tppubtype = {article} } During the first 2 years of larval rearing trials with Atlantic bluefin tuna, survival was a challenging issue. As bacterial colonization of the gut has been shown to play a key role for other species, we studied the profiles of the microbiota associated with individual larvae at different stages in three distant hatcheries. The Bacterial Community Profile (BCP) was quantified based on PCR-DGGE analyses of partial amplicons from 16S rDNA. Considerable individual variability in BCP was observed before onset of feeding, and the BCP did not show regular fluctuation during ontogenesis. Microalgae were added to the rearing tanks in two of the three hatcheries, but it was not possible to distinguish the effect of location from the effect of algal addition on BCP. In one hatchery, the larvae were reared either with algal addition or in mesocosm, but due to high individual variability, no significant difference in BCP was detected between the two groups. It was hypothesized that this variability was caused by differences in health, physiological status and developmental stage of the larvae. A practical conclusion from the study is the need to analyse a considerable number of individuals to reflect statistically significant differences between the microbial communities associated with rearing groups. © 2012 John Wiley & Sons Ltd. |
2011 |
Katharios, P; Kokkari, K; Papadaki, M; Papandroulakis, N Systemic granulomas in cultured meagre, Argyrosomus regius. Inproceedings pp. 537–538, European Aquaculture Society, Rhodes, Greece, 2011, (Publication Title: Aquaculture Europe 11 Type: Conference Paper). @inproceedings{katharios_systemic_2011, title = {Systemic granulomas in cultured meagre, Argyrosomus regius.}, author = {P Katharios and K Kokkari and M Papadaki and N Papandroulakis}, year = {2011}, date = {2011-10-01}, pages = {537--538}, publisher = {European Aquaculture Society}, address = {Rhodes, Greece}, note = {Publication Title: Aquaculture Europe 11 Type: Conference Paper}, keywords = {}, pubstate = {published}, tppubtype = {inproceedings} } |
Fanouraki, E; Mylonas, C C; Papandroulakis, N; Pavlidis, M Species specificity in the magnitude and duration of the acute stress response in Mediterranean marine fish in culture Journal Article General and Comparative Endocrinology, 173 (2), pp. 313–322, 2011, ISSN: 00166480, (Publisher: Academic Press Inc.). @article{fanouraki_species_2011, title = {Species specificity in the magnitude and duration of the acute stress response in Mediterranean marine fish in culture}, author = {E Fanouraki and C C Mylonas and N Papandroulakis and M Pavlidis}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-79961127644&doi=10.1016%2fj.ygcen.2011.06.004&partnerID=40&md5=193a6e0e97c4f57c5cf13a1562900142}, doi = {10.1016/j.ygcen.2011.06.004}, issn = {00166480}, year = {2011}, date = {2011-01-01}, journal = {General and Comparative Endocrinology}, volume = {173}, number = {2}, pages = {313--322}, abstract = {The aim of the present study was to examine the species-specific stress response for seven Mediterranean fishes in culture. Also, to evaluate the method of measuring free cortisol concentration in the rearing water as a non-invasive and reliable indicator of stress in marine species, of aquaculture importance. Gilthead sea bream, Sparus aurata (Sparidae); common dentex, Dentex dentex (Sparidae); common Pandora, Pagellus erythrinus (Sparidae); sharpsnout sea bream, Diplodus puntazzo (Sparidae); dusky grouper, Epinephelus marginatus (Serranidae); meagre, Argyrosomus regius (Sciaenidae) and European sea bass, Dicentrarchus labrax (Moronidae) were subjected to identical acute stress (5-6 min chasing and 1-1.5. min air exposure) under the same environmental conditions and samples were analyzed by the same procedures. Results indicated that there was a clear species-specificity in the magnitude, timing and duration of the stress response in terms of cortisol, glucose and lactate. European sea bass showed a very high response and dusky grouper and meagre a very low response, except plasma glucose concentrations of dusky grouper which was constantly high, while sharpsnout sea bream presented a protracted stress response, up to 8 h. The present study confirmed that free cortisol release rate into the water can be used as a reliable stress indicator. © 2011 Elsevier Inc.}, note = {Publisher: Academic Press Inc.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The aim of the present study was to examine the species-specific stress response for seven Mediterranean fishes in culture. Also, to evaluate the method of measuring free cortisol concentration in the rearing water as a non-invasive and reliable indicator of stress in marine species, of aquaculture importance. Gilthead sea bream, Sparus aurata (Sparidae); common dentex, Dentex dentex (Sparidae); common Pandora, Pagellus erythrinus (Sparidae); sharpsnout sea bream, Diplodus puntazzo (Sparidae); dusky grouper, Epinephelus marginatus (Serranidae); meagre, Argyrosomus regius (Sciaenidae) and European sea bass, Dicentrarchus labrax (Moronidae) were subjected to identical acute stress (5-6 min chasing and 1-1.5. min air exposure) under the same environmental conditions and samples were analyzed by the same procedures. Results indicated that there was a clear species-specificity in the magnitude, timing and duration of the stress response in terms of cortisol, glucose and lactate. European sea bass showed a very high response and dusky grouper and meagre a very low response, except plasma glucose concentrations of dusky grouper which was constantly high, while sharpsnout sea bream presented a protracted stress response, up to 8 h. The present study confirmed that free cortisol release rate into the water can be used as a reliable stress indicator. © 2011 Elsevier Inc. |
Mozes, N; Papandroulakis, N; Vergara, J M; Biswas, A; Takii, K; Ntatsopoulos, A Production Systems Incollection Sparidae: Biology and Aquaculture of Gilthead Sea Bream and other Species, pp. 169 – 198, 2011. @incollection{mozes_production_2011, title = {Production Systems}, author = {N Mozes and N Papandroulakis and J M Vergara and A Biswas and K Takii and A Ntatsopoulos}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-84880137091&partnerID=40&md5=1b39bd7731e72f1fb3eae849a1e8b211}, year = {2011}, date = {2011-01-01}, booktitle = {Sparidae: Biology and Aquaculture of Gilthead Sea Bream and other Species}, pages = {169 -- 198}, abstract = {Fish farming of sparids has started with the success in artificially hatched red sea bream (Pagrus major) larvae in Japan and domestication of sea bream (Sparus aurat) in the Mediterranean. Over the years the culture of these two species has developed into large-scale industries. This chapter focuses on production systems, covering with the hatchery stage, describing different rearing techniques and technologies, and finalizing with growout metabolic aspects and related environmental issues. Hatcheries of sparids include larval rearing, planktonic food chain production (both phytoplankton and zooplankton), and nursery sections. The process of larval rearing represents probably the major bottleneck of the rearing, as in all aquaculture activities. Hatcheries applying intensive or semi-intensive techniques are producing juveniles at size of 2-5 g that are transferred to an ongrowing cage or land-based systems, or may include a preongrowing period (up to a size of 10-30 g) in case of open sea cages. Floating cages in protected or semiprotected sites are the dominant technology used for the production of sea bream in the Mediterranean and are widely used for red sea bream in Japan aswell. Limited locations and increasing competition and conflicts with other users of coastal areas have promoted the development of offshore open sea cages. Land-based systems are used for sparids in Japan and in the Mediterranean for many years and developed from extensive to a modern and intensive production system, yet with limited use. The chapter also includes a quantitative description of four basic metabolic rates required for the design of a production system, using the sea bream as a model (growth; feeding; respiration of O2 and CO2; excretion of metabolites) and describes the required environment for culture in terms of water quality and photoperiod manipulations. At the last section, the impact of sparids production on environmental issues is discussed, including aspects of source impact, escapes, nutrient enrichment, and long-term sustainability issues. Finally, some future directions of research and development of sparids production systems is discussed, including further development of the mesocosm approach, advancing offshore technologies, and improving performances of land-based recirculating and integrated systems. © 2011 Blackwell Publishing Ltd.}, keywords = {}, pubstate = {published}, tppubtype = {incollection} } Fish farming of sparids has started with the success in artificially hatched red sea bream (Pagrus major) larvae in Japan and domestication of sea bream (Sparus aurat) in the Mediterranean. Over the years the culture of these two species has developed into large-scale industries. This chapter focuses on production systems, covering with the hatchery stage, describing different rearing techniques and technologies, and finalizing with growout metabolic aspects and related environmental issues. Hatcheries of sparids include larval rearing, planktonic food chain production (both phytoplankton and zooplankton), and nursery sections. The process of larval rearing represents probably the major bottleneck of the rearing, as in all aquaculture activities. Hatcheries applying intensive or semi-intensive techniques are producing juveniles at size of 2-5 g that are transferred to an ongrowing cage or land-based systems, or may include a preongrowing period (up to a size of 10-30 g) in case of open sea cages. Floating cages in protected or semiprotected sites are the dominant technology used for the production of sea bream in the Mediterranean and are widely used for red sea bream in Japan aswell. Limited locations and increasing competition and conflicts with other users of coastal areas have promoted the development of offshore open sea cages. Land-based systems are used for sparids in Japan and in the Mediterranean for many years and developed from extensive to a modern and intensive production system, yet with limited use. The chapter also includes a quantitative description of four basic metabolic rates required for the design of a production system, using the sea bream as a model (growth; feeding; respiration of O2 and CO2; excretion of metabolites) and describes the required environment for culture in terms of water quality and photoperiod manipulations. At the last section, the impact of sparids production on environmental issues is discussed, including aspects of source impact, escapes, nutrient enrichment, and long-term sustainability issues. Finally, some future directions of research and development of sparids production systems is discussed, including further development of the mesocosm approach, advancing offshore technologies, and improving performances of land-based recirculating and integrated systems. © 2011 Blackwell Publishing Ltd. |
Pavlidis, M; Karantzali, E; Fanouraki, E; Barsakis, C; Kollias, S; Papandroulakis, N Aquaculture, 315 , pp. 125 – 130, 2011. @article{pavlidis_onset_2011, title = {Onset of the primary stress in European sea bass Dicentrarhus labrax, as indicated by whole body cortisol in relation to glucocorticoid receptor during early development}, author = {M Pavlidis and E Karantzali and E Fanouraki and C Barsakis and S Kollias and N Papandroulakis}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-79954613934&partnerID=40&md5=82f46f8197433d61b232af188da3979d}, year = {2011}, date = {2011-01-01}, journal = {Aquaculture}, volume = {315}, pages = {125 -- 130}, abstract = {The temporal patterns of whole body cortisol, the onset of the primary stress response and mRNA abundance of the two glucocorticoid receptors isoforms during early ontogeny was investigated for the first time in the European sea bass, Dicentrarchus labrax. The ontogenetic profile of basal cortisol content was similar to that observed in other pelagic marine species, with minimum values at hatching (0.12±0.01ngg-1), a slight increase at first feeding (2.44±0.71ngg-1) and a first peak at flexion (47.91±6.72ngg-1). However, basal cortisol content at flexion and at the more advanced developmental stages was one of the highest reported for fish. Exposure to a physical stressor (high currents) increased whole body cortisol above control levels at all developmental stages examined (first feeding, pre-larvae, flexion, post flexion, end of metamorphosis and juveniles). However, the magnitude of the cortisol response was low at first feeding and high in juvenile fish. There was a greater number of GR-1 than GR-2 transcripts levels in embryos, pre-larvae and larvae of European sea bass. GR-1 transcripts showed minimum mRNA abundance in embryos and at post flexion and maximum at the end of metamorphosis and in juveniles. The mRNA transcript levels of GR-2 showed a slight increase at hatch to reach a peak in post flexion larvae and in juveniles but these differences were not statistically significant. These results indicate that the onset of cortisol production in European sea bass is near the transition from endogenous to exogenous feeding and show that fish are capable of a stress-induced stimulation of cortisol production even at first feeding. © 2010 Elsevier B.V.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The temporal patterns of whole body cortisol, the onset of the primary stress response and mRNA abundance of the two glucocorticoid receptors isoforms during early ontogeny was investigated for the first time in the European sea bass, Dicentrarchus labrax. The ontogenetic profile of basal cortisol content was similar to that observed in other pelagic marine species, with minimum values at hatching (0.12±0.01ngg-1), a slight increase at first feeding (2.44±0.71ngg-1) and a first peak at flexion (47.91±6.72ngg-1). However, basal cortisol content at flexion and at the more advanced developmental stages was one of the highest reported for fish. Exposure to a physical stressor (high currents) increased whole body cortisol above control levels at all developmental stages examined (first feeding, pre-larvae, flexion, post flexion, end of metamorphosis and juveniles). However, the magnitude of the cortisol response was low at first feeding and high in juvenile fish. There was a greater number of GR-1 than GR-2 transcripts levels in embryos, pre-larvae and larvae of European sea bass. GR-1 transcripts showed minimum mRNA abundance in embryos and at post flexion and maximum at the end of metamorphosis and in juveniles. The mRNA transcript levels of GR-2 showed a slight increase at hatch to reach a peak in post flexion larvae and in juveniles but these differences were not statistically significant. These results indicate that the onset of cortisol production in European sea bass is near the transition from endogenous to exogenous feeding and show that fish are capable of a stress-induced stimulation of cortisol production even at first feeding. © 2010 Elsevier B.V. |
2010 |
Rigos, G; Katharios, P; Papandroulakis, N Single intramuscular administration of long-acting oxytetracycline in grouper (Epinephelus marginatus) Journal Article Turkish Journal of Veterinary and Animal Sciences, 34 (5), pp. 441–445, 2010, ISSN: 13000128. @article{rigos_single_2010, title = {Single intramuscular administration of long-acting oxytetracycline in grouper (Epinephelus marginatus)}, author = {G Rigos and P Katharios and N Papandroulakis}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-78650669591&doi=10.3906%2fvet-0906-10&partnerID=40&md5=31f361ba713c356eb768142370d17368}, doi = {10.3906/vet-0906-10}, issn = {13000128}, year = {2010}, date = {2010-01-01}, journal = {Turkish Journal of Veterinary and Animal Sciences}, volume = {34}, number = {5}, pages = {441--445}, abstract = {The plasma concentration of long-acting oxytetracycline (OTC-LA) was measured following a single intramuscular (IM) injection (50 mg/kg) in grouper (Epinephelus marginatus), a common inhabitant of marine aquaria and a potential candidate for fish farming. The experiment was carried out at 20 °C and sampling points were selected at 0.25, 0.5, 1, 2, 4, 6, 8, 12, 24, and 48 h post-administration. OTC concentration in grouper circulation was maintained at high levels for the whole experiment (8.35-39.67 μg/mL) with maximum plasma concentration measured at 1 h postinjection. The area under the curve values was also promising since AUC0-24 and AUC 0-48 were calculated to be high (363.45 and 668.73 μg h/mL, respectively). Due to the high OTC levels accomplished for prolonged period of time, a single administration of OTC-LA could be an ideal route in cases when multiple handling is unwanted and big animals such as grouper are to be treated. © Tübi̇tak.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The plasma concentration of long-acting oxytetracycline (OTC-LA) was measured following a single intramuscular (IM) injection (50 mg/kg) in grouper (Epinephelus marginatus), a common inhabitant of marine aquaria and a potential candidate for fish farming. The experiment was carried out at 20 °C and sampling points were selected at 0.25, 0.5, 1, 2, 4, 6, 8, 12, 24, and 48 h post-administration. OTC concentration in grouper circulation was maintained at high levels for the whole experiment (8.35-39.67 μg/mL) with maximum plasma concentration measured at 1 h postinjection. The area under the curve values was also promising since AUC0-24 and AUC 0-48 were calculated to be high (363.45 and 668.73 μg h/mL, respectively). Due to the high OTC levels accomplished for prolonged period of time, a single administration of OTC-LA could be an ideal route in cases when multiple handling is unwanted and big animals such as grouper are to be treated. © Tübi̇tak. |
Ghysen, A; Schuster, K; Coves, D; de la Gandara, F; Papandroulakis, N; Ortega, A Development of the posterior lateral line system in Thunnus thynnus, the atlantic blue-fin tuna, and in its close relative Sarda sarda Journal Article International Journal of Developmental Biology, 54 , pp. 1317 – 1322, 2010. @article{ghysen_development_2010, title = {Development of the posterior lateral line system in Thunnus thynnus, the atlantic blue-fin tuna, and in its close relative Sarda sarda}, author = {A Ghysen and K Schuster and D Coves and F de la Gandara and N Papandroulakis and A Ortega}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-77957722338&partnerID=40&md5=7078edf09e5c0cbbae23cc9c296e6260}, year = {2010}, date = {2010-01-01}, journal = {International Journal of Developmental Biology}, volume = {54}, pages = {1317 -- 1322}, abstract = {The lateral line system of amphibians and fish comprises a large number of individual mechanosensory organs, the neuromasts, and their sensory neurons. The pattern of neuromasts varies markedly between species, yet the embryonic pattern is highly conserved from the relatively basal zebrafish, Danio rerio, to more derived species. Here we examine in more detail the development of the posterior lateral line (PLL) in embryos and early larvae of one of the most derived fish species, the blue-fin tuna Thunnus thynnus, and of its close relative, the Atlantic bonito Sarda sarda. We show that the basic features of embryonic PLL development, including the migratory properties of the PLL primordium, the patterning of neuromasts and their innervation, are largely conserved between zebrafish and tuna. However, Thunnus and Sarda embryos differ from Danio in three respects: the larger size of the neuromast cupula, the capability of mature neuromasts to migrate dorsally, and the presence of a single, precisely located terminal neuromast. © 2010 UBC Press.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The lateral line system of amphibians and fish comprises a large number of individual mechanosensory organs, the neuromasts, and their sensory neurons. The pattern of neuromasts varies markedly between species, yet the embryonic pattern is highly conserved from the relatively basal zebrafish, Danio rerio, to more derived species. Here we examine in more detail the development of the posterior lateral line (PLL) in embryos and early larvae of one of the most derived fish species, the blue-fin tuna Thunnus thynnus, and of its close relative, the Atlantic bonito Sarda sarda. We show that the basic features of embryonic PLL development, including the migratory properties of the PLL primordium, the patterning of neuromasts and their innervation, are largely conserved between zebrafish and tuna. However, Thunnus and Sarda embryos differ from Danio in three respects: the larger size of the neuromast cupula, the capability of mature neuromasts to migrate dorsally, and the presence of a single, precisely located terminal neuromast. © 2010 UBC Press. |
2009 |
Mylonas, C C; Pavlidis, M; Papandroulakis, N; Zaiss, M M; Tsafarakis, D; Papadakis, I E; Varsamos, S Growth performance and osmoregulation in the shi drum (Umbrina cirrosa) adapted to different environmental salinities Journal Article Aquaculture, 287 (1-2), pp. 203–210, 2009, ISSN: 00448486. @article{mylonas_growth_2009, title = {Growth performance and osmoregulation in the shi drum (Umbrina cirrosa) adapted to different environmental salinities}, author = {C C Mylonas and M Pavlidis and N Papandroulakis and M M Zaiss and D Tsafarakis and I E Papadakis and S Varsamos}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-58049194052&doi=10.1016%2fj.aquaculture.2008.10.024&partnerID=40&md5=a637928fdea05d4d7f37eda6ccf92d9c}, doi = {10.1016/j.aquaculture.2008.10.024}, issn = {00448486}, year = {2009}, date = {2009-01-01}, journal = {Aquaculture}, volume = {287}, number = {1-2}, pages = {203--210}, abstract = {In order to investigate the ability of shi drum (Umbrina cirrosa) to be reared at diverse locations, growth and osmoregulatory performance were assessed at full-strength seawater (40 psu), nearly iso-osmotic water (10 psu) and low salinity water (4 psu). At the end of the 84-day experimental period, fish reared at 4 psu displayed shorter mean fork length, lower mean body weight, lower specific growth rate and higher food conversion efficiency than fish reared at 10 or 40 psu. The effect of salinity on growth performance was also reflected by changes in plasma triglycerides and cholesterol, with fish reared at 4 psu exhibiting the lowest mean concentrations, while there was no significant difference in mean plasma glucose concentrations among treatments. Plasma osmolality was lower at 4 psu from day 42 onwards, while there was no significant difference in mean plasma K+ and Cl- concentrations. Plasma sodium and gill Na+/K+-ATPase activity showed minimum values on day 42 at 4 psu, but at the end of the experiment there was no difference among groups. Pavement cells, mucus cells and chloride cells were identified by histology on the gill epithelium. In shi drum reared at full seawater, mucus cells contained a mixture of acid and neutral mucins, whereas in fish adapted to hypo-osmotic environment neutral mucins were mainly observed. There was a significant increase in chloride cell number over the course of the study in all fish, but there was no difference among the three experimental salinities. Finally, in fish reared at 40 psu salinity, chloride cells increased in size significantly compared to fish adapted to 4 psu, whereas at 10 psu after 42 d there was a significant reduction in chloride cell size. These results indicate that shi drum reared from full-strength seawater to iso-osmotic salinity do not face any osmoregulatory imbalance, while fish reared in hypo-osmotic water displayed osmoregulatory impairment and low growth performance. © 2008 Elsevier B.V. All rights reserved.}, keywords = {}, pubstate = {published}, tppubtype = {article} } In order to investigate the ability of shi drum (Umbrina cirrosa) to be reared at diverse locations, growth and osmoregulatory performance were assessed at full-strength seawater (40 psu), nearly iso-osmotic water (10 psu) and low salinity water (4 psu). At the end of the 84-day experimental period, fish reared at 4 psu displayed shorter mean fork length, lower mean body weight, lower specific growth rate and higher food conversion efficiency than fish reared at 10 or 40 psu. The effect of salinity on growth performance was also reflected by changes in plasma triglycerides and cholesterol, with fish reared at 4 psu exhibiting the lowest mean concentrations, while there was no significant difference in mean plasma glucose concentrations among treatments. Plasma osmolality was lower at 4 psu from day 42 onwards, while there was no significant difference in mean plasma K+ and Cl- concentrations. Plasma sodium and gill Na+/K+-ATPase activity showed minimum values on day 42 at 4 psu, but at the end of the experiment there was no difference among groups. Pavement cells, mucus cells and chloride cells were identified by histology on the gill epithelium. In shi drum reared at full seawater, mucus cells contained a mixture of acid and neutral mucins, whereas in fish adapted to hypo-osmotic environment neutral mucins were mainly observed. There was a significant increase in chloride cell number over the course of the study in all fish, but there was no difference among the three experimental salinities. Finally, in fish reared at 40 psu salinity, chloride cells increased in size significantly compared to fish adapted to 4 psu, whereas at 10 psu after 42 d there was a significant reduction in chloride cell size. These results indicate that shi drum reared from full-strength seawater to iso-osmotic salinity do not face any osmoregulatory imbalance, while fish reared in hypo-osmotic water displayed osmoregulatory impairment and low growth performance. © 2008 Elsevier B.V. All rights reserved. |
2008 |
Tevdoradze, E; Kokashvili, T; Skhirtladze, N; Balarjishvili, N; Tskhvediani, A; Lashkhi, N; Kutateladze, M; Tediashvili, M; Katharios, P; Papandroulakis, N Isolation and preliminary characterization of Phages specific to Mediterranean fish pathogens. Inproceedings Phage Biology, Ecology and Therapy Meeting, Tbilisi, Georgia, 2008. @inproceedings{tevdoradze_isolation_2008, title = {Isolation and preliminary characterization of Phages specific to Mediterranean fish pathogens.}, author = {E Tevdoradze and T Kokashvili and N Skhirtladze and N Balarjishvili and A Tskhvediani and N Lashkhi and M Kutateladze and M Tediashvili and P Katharios and N Papandroulakis}, year = {2008}, date = {2008-06-01}, booktitle = {Phage Biology, Ecology and Therapy Meeting}, address = {Tbilisi, Georgia}, keywords = {}, pubstate = {published}, tppubtype = {inproceedings} } |
Katharios, P; Papadaki, M; Papandroulakis, N; Divanach, P Severe mortality in mesocosm-reared sharpsnout sea bream Diplodus puntazzo larvae due to epitheliocystis infection Journal Article Diseases of Aquatic Organisms, 82 (1), pp. 55–60, 2008, ISSN: 01775103. @article{katharios_severe_2008, title = {Severe mortality in mesocosm-reared sharpsnout sea bream Diplodus puntazzo larvae due to epitheliocystis infection}, author = {P Katharios and M Papadaki and N Papandroulakis and P Divanach}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-56649123097&doi=10.3354%2fdao01968&partnerID=40&md5=1c652a653ce36b0e7ae3f6a7b9d1aff6}, doi = {10.3354/dao01968}, issn = {01775103}, year = {2008}, date = {2008-01-01}, journal = {Diseases of Aquatic Organisms}, volume = {82}, number = {1}, pages = {55--60}, abstract = {This paper describes severe mortalities recorded in sharpsnout sea bream Diplodus puntazzo larvae reared in mesocosms. The mortalities were attributed to epitheliocystis infection. The pathology associated with the disease is described using histological techniques. Microscopical examination showed a massive infection of the skin, fins, and oral cavity, with impaired feeding, respiration, and osmoregulation being the most likely cause of death. This is the first report of epitheliocystis disease in sharpsnout sea bream and in fish at such an early developmental stage. © Inter-Research 2008.}, keywords = {}, pubstate = {published}, tppubtype = {article} } This paper describes severe mortalities recorded in sharpsnout sea bream Diplodus puntazzo larvae reared in mesocosms. The mortalities were attributed to epitheliocystis infection. The pathology associated with the disease is described using histological techniques. Microscopical examination showed a massive infection of the skin, fins, and oral cavity, with impaired feeding, respiration, and osmoregulation being the most likely cause of death. This is the first report of epitheliocystis disease in sharpsnout sea bream and in fish at such an early developmental stage. © Inter-Research 2008. |
Fanouraki, E; Papandroulakis, N; Ellis, T; Mylonas, C C; Scott, A P; Pavlidis, M Water cortisol is a reliable indicator of stress in European sea bass, Dicentrarchus labrax Journal Article Behaviour, 145 (10), pp. 1267–1281, 2008, ISSN: 00057959. @article{fanouraki_water_2008, title = {Water cortisol is a reliable indicator of stress in European sea bass, Dicentrarchus labrax}, author = {E Fanouraki and N Papandroulakis and T Ellis and C C Mylonas and A P Scott and M Pavlidis}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-53549135481&doi=10.1163%2f156853908785765818&partnerID=40&md5=42a3c0a4a9e00431db12a315e5bb27c7}, doi = {10.1163/156853908785765818}, issn = {00057959}, year = {2008}, date = {2008-01-01}, journal = {Behaviour}, volume = {145}, number = {10}, pages = {1267--1281}, abstract = {This study examined cortisol release into the water by European sea bass, Dicentrarchus labrax. The time-course of plasma and water cortisol concentrations were determined in adult fish subjected to acute stress, by sampling blood and water at 0 h (before stress) and 0.5, 1, 2, 4, 8 and 24 h after stress. Sea bass showed a typical stress response, with plasma glucose and lactate concentrations peaking at 2 h, and plasma cortisol levels peaking at 1 h. Cortisol release rate into the water increased in response to stress and was positively correlated with plasma cortisol concentrations. In a further trial, juvenile fish were confined at densities of 20 and 50 kg/m3 and water cortisol was evaluated over a 24 h period. Cortisol release rates peaked between 0-1 h in the high and 1-2 h in the low density group. In conclusion, these results provide strong evidence that cortisol release rate into the water can be used as a non-invasive method for the assessment of the stress response and that although sea bass presents a high blood stress response after exposure to acute husbandry stressors, it is releasing less cortisol into the water compared to other species previously examined. © 2008 Brill.}, keywords = {}, pubstate = {published}, tppubtype = {article} } This study examined cortisol release into the water by European sea bass, Dicentrarchus labrax. The time-course of plasma and water cortisol concentrations were determined in adult fish subjected to acute stress, by sampling blood and water at 0 h (before stress) and 0.5, 1, 2, 4, 8 and 24 h after stress. Sea bass showed a typical stress response, with plasma glucose and lactate concentrations peaking at 2 h, and plasma cortisol levels peaking at 1 h. Cortisol release rate into the water increased in response to stress and was positively correlated with plasma cortisol concentrations. In a further trial, juvenile fish were confined at densities of 20 and 50 kg/m3 and water cortisol was evaluated over a 24 h period. Cortisol release rates peaked between 0-1 h in the high and 1-2 h in the low density group. In conclusion, these results provide strong evidence that cortisol release rate into the water can be used as a non-invasive method for the assessment of the stress response and that although sea bass presents a high blood stress response after exposure to acute husbandry stressors, it is releasing less cortisol into the water compared to other species previously examined. © 2008 Brill. |
Fauvel, C; Suquet, M; Severe, A; Mylonas, C C; Nikos, Papandroulakis N Slow-release GnRHa treatment prevented atresia during vitellogenesis and induced ovulation of captive wreckfish (Polyprion americanus) Journal Article Cybium, 32 (2 SUPPL.), pp. 191, 2008, ISSN: 03990974. @article{fauvel_slow-release_2008, title = {Slow-release GnRHa treatment prevented atresia during vitellogenesis and induced ovulation of captive wreckfish (Polyprion americanus)}, author = {C Fauvel and M Suquet and A Severe and C C Mylonas and N Papandroulakis Nikos}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-73349093302&partnerID=40&md5=826b3fc6c38bb4145d12218fc6873683}, issn = {03990974}, year = {2008}, date = {2008-01-01}, journal = {Cybium}, volume = {32}, number = {2 SUPPL.}, pages = {191}, abstract = {The potential of wreckfish (Polyprion americanus) to breed in captivity was examined. Ovarian activity varied seasonally, with vitellogenesis beginning in November and ending in May. Slow-release implant with gonadotropinreleasing hormone agonist (GnRHa) prevented atresia, and both GnRHa injections or implants at the end of vitellogenesis triggered ovulation after 7 days. Spontaneous spawning was obtained only in one female, and the few eggs produced were of poor viability. Manual stripping and artificial fertilization produced viable gametes and embryos. Therefore, present captivity conditions inhibited final oocyte maturation (FOM) and spawning, but not vitellogenesis and spermatogenesis. GnRHa treatments stimulate FOM and ovulation of viable eggs.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The potential of wreckfish (Polyprion americanus) to breed in captivity was examined. Ovarian activity varied seasonally, with vitellogenesis beginning in November and ending in May. Slow-release implant with gonadotropinreleasing hormone agonist (GnRHa) prevented atresia, and both GnRHa injections or implants at the end of vitellogenesis triggered ovulation after 7 days. Spontaneous spawning was obtained only in one female, and the few eggs produced were of poor viability. Manual stripping and artificial fertilization produced viable gametes and embryos. Therefore, present captivity conditions inhibited final oocyte maturation (FOM) and spawning, but not vitellogenesis and spermatogenesis. GnRHa treatments stimulate FOM and ovulation of viable eggs. |
Pavlidis, M; Karkana, M; Fanouraki, E; Papandroulakis, N Environmental control of skin colour in the red porgy, Pagrus pagrus Journal Article Aquaculture Research, 39 , pp. 837 – 849, 2008. @article{pavlidis_environmental_2008, title = {Environmental control of skin colour in the red porgy, Pagrus pagrus}, author = {M Pavlidis and M Karkana and E Fanouraki and N Papandroulakis}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-44349156079&partnerID=40&md5=0b17bd17f9a8402649183a7efc5e4dad}, year = {2008}, date = {2008-01-01}, journal = {Aquaculture Research}, volume = {39}, pages = {837 -- 849}, abstract = {Fish display sophisticated skin chromatic properties that are of considerable ecological, physiological and behavioural importance. The aim of study was to investigate the role of important physical parameters (background colour, lighting spectrum, light intensity and water temperature) on skin colour to gain better knowledge of the environmental factors that regulate pigmentation in cultured red porgy, Pagrus pagrus. All tested physical parameters had a significant effect on skin lightness, especially in the dorsal body area; low light intensity, blue spectrum, a water temperature of 19°C and a white background significantly increased skin lightness. This effect was mediated through changes in melanophore motility and/or skin melanin concentration. None of the examined factors affected skin hue while a significant decrease in skin entire colour index (a combination of hue and chroma) was found only in white background-adapted fish. It is concluded that all tested physical factors are important regulators of skin lightness. © 2008 The Authors.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Fish display sophisticated skin chromatic properties that are of considerable ecological, physiological and behavioural importance. The aim of study was to investigate the role of important physical parameters (background colour, lighting spectrum, light intensity and water temperature) on skin colour to gain better knowledge of the environmental factors that regulate pigmentation in cultured red porgy, Pagrus pagrus. All tested physical parameters had a significant effect on skin lightness, especially in the dorsal body area; low light intensity, blue spectrum, a water temperature of 19°C and a white background significantly increased skin lightness. This effect was mediated through changes in melanophore motility and/or skin melanin concentration. None of the examined factors affected skin hue while a significant decrease in skin entire colour index (a combination of hue and chroma) was found only in white background-adapted fish. It is concluded that all tested physical factors are important regulators of skin lightness. © 2008 The Authors. |
Papandroulakis, N; Mylonas, C C; Syggelaki, E; Katharios, P; Divanach, P First reproduction of captive-reared wreckfish (Polyprion americanus) using GnRH implants. Inproceedings Aquaculture Europe 08, European Aquaculture Society, Krakow, Poland, 2008, (Backup Publisher: European Aquaculture Society). @inproceedings{papandroulakis_first_2008, title = {First reproduction of captive-reared wreckfish (Polyprion americanus) using GnRH implants.}, author = {N Papandroulakis and C C Mylonas and E Syggelaki and P Katharios and P Divanach}, year = {2008}, date = {2008-01-01}, booktitle = {Aquaculture Europe 08}, publisher = {European Aquaculture Society}, address = {Krakow, Poland}, note = {Backup Publisher: European Aquaculture Society}, keywords = {}, pubstate = {published}, tppubtype = {inproceedings} } |
Katharios, P; Papandroulakis, N; Papadaki, M; Syggelaki, E; Tzamarias, D; Gounalaki, N; Divanach, P Pseudomonas putida infection in captive wreckfish Polyprion americanus. A case report. Inproceedings Aquaculture Europe 08, pp. 307, European Aquacultrure Society, Krakow, Poland, 2008, (Backup Publisher: European Aquacultrure Society). @inproceedings{katharios_pseudomonas_2008, title = {Pseudomonas putida infection in captive wreckfish Polyprion americanus. A case report.}, author = {P Katharios and N Papandroulakis and M Papadaki and E Syggelaki and D Tzamarias and N Gounalaki and P Divanach}, year = {2008}, date = {2008-01-01}, booktitle = {Aquaculture Europe 08}, pages = {307}, publisher = {European Aquacultrure Society}, address = {Krakow, Poland}, note = {Backup Publisher: European Aquacultrure Society}, keywords = {}, pubstate = {published}, tppubtype = {inproceedings} } |
2006 |
P., Katharios; N., Papandroulakis; C., Hayward; M., Asderis; Divanach, P Parasitic monogeneans in cultured fish in Crete. Methods for treatment. Inproceedings HCMR, (Ed.): 8th Congress of Oceanography and Fisheries, Thessaloniki, Greece, 2006. @inproceedings{katharios_parasitic_2006, title = {Parasitic monogeneans in cultured fish in Crete. Methods for treatment.}, author = {Katharios P. and Papandroulakis N. and Hayward C. and Asderis M. and P Divanach}, editor = {HCMR}, year = {2006}, date = {2006-06-01}, booktitle = {8th Congress of Oceanography and Fisheries}, address = {Thessaloniki, Greece}, keywords = {}, pubstate = {published}, tppubtype = {inproceedings} } |
Chatzifotis, S; Martin-Prat, Villamor A; Limberis, N; Papandroulakis, N; Divanach, P First data on growth of cultured brown meagre Sciaena umbra using diets with different protein and fat contents Journal Article Fisheries Science, 72 (1), pp. 83–88, 2006, ISSN: 09199268. @article{chatzifotis_first_2006, title = {First data on growth of cultured brown meagre Sciaena umbra using diets with different protein and fat contents}, author = {S Chatzifotis and A Villamor Martin-Prat and N Limberis and N Papandroulakis and P Divanach}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-33645073706&doi=10.1111%2fj.1444-2906.2006.01120.x&partnerID=40&md5=710f8cdfc624dfbc7ecd98730393dbf5}, doi = {10.1111/j.1444-2906.2006.01120.x}, issn = {09199268}, year = {2006}, date = {2006-01-01}, journal = {Fisheries Science}, volume = {72}, number = {1}, pages = {83--88}, abstract = {Brown meagre Sciaena umbra Linnaeus 1758 is a demersal species living at depths of 0-200 m with a wide distribution in the Mediterranean Sea, Black Sea and eastern Atlantic Ocean. It exhibits nocturnal behavior and occupies bottom caves and seabeds covered with vegetation. This study presents the first data on brown meagre growth under culture conditions and contributes some basic information on its dietary protein requirement by feeding isoenergetic diets with different protein-lipid ratios by means of self-feeders. Fish with 78.8 ± 15.8 g (mean ± standard deviation) body weight were divided into four groups and subjected to four different feeding regimes with three replications for 77 days. In the first group, fish were supplied with a high protein and low fat diet (HPLF, 52: 8 w/w fat-protein ratio), the second one a medium protein and medium fat diet (MPMF, 42: 14), the third with a low protein and high fat diet (LPHF, 31: 23). In the fourth group, fish had access to both HPLF and LPHF diets. Fish fed on HPLF and MPMF diets showed significantly better growth and feed conversion ratios than fish fed on the LPHF diet. Fish with access to HPLF and LPHF diets exhibited comparable growth to the HPLF group but their feed conversion ratio was significantly higher. The condition factor and hepatosomatic index revealed no significant differences between dietary regimes. The liver of brown meagre may serve as a depository organ for energy, judging from its relatively high lipid content (39-43%).}, keywords = {}, pubstate = {published}, tppubtype = {article} } Brown meagre Sciaena umbra Linnaeus 1758 is a demersal species living at depths of 0-200 m with a wide distribution in the Mediterranean Sea, Black Sea and eastern Atlantic Ocean. It exhibits nocturnal behavior and occupies bottom caves and seabeds covered with vegetation. This study presents the first data on brown meagre growth under culture conditions and contributes some basic information on its dietary protein requirement by feeding isoenergetic diets with different protein-lipid ratios by means of self-feeders. Fish with 78.8 ± 15.8 g (mean ± standard deviation) body weight were divided into four groups and subjected to four different feeding regimes with three replications for 77 days. In the first group, fish were supplied with a high protein and low fat diet (HPLF, 52: 8 w/w fat-protein ratio), the second one a medium protein and medium fat diet (MPMF, 42: 14), the third with a low protein and high fat diet (LPHF, 31: 23). In the fourth group, fish had access to both HPLF and LPHF diets. Fish fed on HPLF and MPMF diets showed significantly better growth and feed conversion ratios than fish fed on the LPHF diet. Fish with access to HPLF and LPHF diets exhibited comparable growth to the HPLF group but their feed conversion ratio was significantly higher. The condition factor and hepatosomatic index revealed no significant differences between dietary regimes. The liver of brown meagre may serve as a depository organ for energy, judging from its relatively high lipid content (39-43%). |
Katharios, P; Papandroulakis, N; Divanach, P Treatment of Microcotyle sp. (Monogenea) on the gills of cage-cultured red porgy, Pagrus pagrus following baths with formalin and mebendazole Journal Article Aquaculture, 251 (2-4), pp. 167–171, 2006, ISSN: 00448486. @article{katharios_treatment_2006, title = {Treatment of Microcotyle sp. (Monogenea) on the gills of cage-cultured red porgy, Pagrus pagrus following baths with formalin and mebendazole}, author = {P Katharios and N Papandroulakis and P Divanach}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-31344445980&doi=10.1016%2fj.aquaculture.2005.05.046&partnerID=40&md5=91ab895aa4134d0252eb1817aaaa56a2}, doi = {10.1016/j.aquaculture.2005.05.046}, issn = {00448486}, year = {2006}, date = {2006-01-01}, journal = {Aquaculture}, volume = {251}, number = {2-4}, pages = {167--171}, abstract = {Two bath treatment trials for the control of the monogenean Microcotyle sp. in the gills of cultured red porgy, Pagrus pagrus using formalin (200 ppm for 1 h) and mebendazole (400 ppm for 1 h) were conducted. Formalin was very effective removing all the parasites from the gills of the infected fish while mebendazole produced no significant result. Based on the results of the trial, formalin was selected for the treatment of a large population of heavily infected red porgies held in sea cages. The results of the treatment are discussed. © 2005 Elsevier B.V. All rights reserved.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Two bath treatment trials for the control of the monogenean Microcotyle sp. in the gills of cultured red porgy, Pagrus pagrus using formalin (200 ppm for 1 h) and mebendazole (400 ppm for 1 h) were conducted. Formalin was very effective removing all the parasites from the gills of the infected fish while mebendazole produced no significant result. Based on the results of the trial, formalin was selected for the treatment of a large population of heavily infected red porgies held in sea cages. The results of the treatment are discussed. © 2005 Elsevier B.V. All rights reserved. |
Katharios, P; Hayward, C; Papandroulakis, N; Divanach, P Pathology of Lamellodiscus spp. (Monogenea) parasitizing the gills of sharpsnout seabream and preliminary results of formalin treatment Journal Article Bulletin of the European Association of Fish Pathologists, 26 (5), pp. 196–201, 2006, ISSN: 01080288. @article{katharios_pathology_2006, title = {Pathology of Lamellodiscus spp. (Monogenea) parasitizing the gills of sharpsnout seabream and preliminary results of formalin treatment}, author = {P Katharios and C Hayward and N Papandroulakis and P Divanach}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-33845670054&partnerID=40&md5=09814c007ac1f9256a311f1d53bc1f34}, issn = {01080288}, year = {2006}, date = {2006-01-01}, journal = {Bulletin of the European Association of Fish Pathologists}, volume = {26}, number = {5}, pages = {196--201}, abstract = {This report describes the pathological effects Lamellodiscus spp. on the gills of the sharpsnout seabream, Diplodus puntazzo and the efficacy of formalin as a treatment. Two species of Lamellodiscus were identified: Lamellodiscus ergensi and L. bidens. The attachment of parasites caused destruction, fusion and hyperplasia of the gill filaments. Formalin was effective in removing the worms when applied as a bath treatment at a concentration of 200mg/ml for one hour.}, keywords = {}, pubstate = {published}, tppubtype = {article} } This report describes the pathological effects Lamellodiscus spp. on the gills of the sharpsnout seabream, Diplodus puntazzo and the efficacy of formalin as a treatment. Two species of Lamellodiscus were identified: Lamellodiscus ergensi and L. bidens. The attachment of parasites caused destruction, fusion and hyperplasia of the gill filaments. Formalin was effective in removing the worms when applied as a bath treatment at a concentration of 200mg/ml for one hour. |
Pavlidis, M; Papandroulakis, N; Divanach, P A method for the comparison of chromaticity parameters in fish skin: Preliminary results for coloration pattern of red skin Sparidae Journal Article Aquaculture, 258 (1-4), pp. 211 – 219, 2006. @article{pavlidis_method_2006, title = {A method for the comparison of chromaticity parameters in fish skin: Preliminary results for coloration pattern of red skin Sparidae}, author = {M Pavlidis and N Papandroulakis and P Divanach}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-33746956857&partnerID=40&md5=00f1e5f14d6fc540ca0f76a0817c61dd}, doi = {https://doi.org/10.1016/j.aquaculture.2006.05.028}, year = {2006}, date = {2006-01-01}, journal = {Aquaculture}, volume = {258}, number = {1-4}, pages = {211 -- 219}, abstract = {Skin coloration patterns in fish are of great physiological, behavioural and ecological importance, can be considered as an index of animal welfare in aquaculture and as an important quality factor for the retail value, especially of red skinned fish. In the present study we developed an appropriate method for comparisons of the skin chromaticity parameters in wild (Pagrus pagrus, Pagrus caeruleostictus, and Dentex gibbosus) and farmed red skin Sparidae and investigated the effect of storage time on skin colour of farmed Pagrus pagrus. The three-dimensional characteristics of colour appearance (lightness - L*, hue - H°ab and chroma -Cab *) were calculated. A new index, named Entire Colour Index (ECI), was developed to express hue and chroma which as combined variables, cannot be considered separately. In all species there was a remarkable dorsoventral gradient in mean L* and H°ab, with the ventral area being statistically significant brighter than the dorsal one. ECI value was species specific but did not show any statistically significant dorsoventral gradient, with the exception of P. pagrus. Skin melanin and carotenoids content presented differences between the Pagrus and the Dentex species that may explain the differences in the observed chromaticity pattern. Storage time affected lightness and hue only in the dorsal skin area. However, the effect of storage on ice was better reflected in mean ECI value which showed a marked decrease from Day 3 to Day 7 in both the dorsal (Day 0: 8.96 ± 0.40; Day 7: 2.86 ± 0.29) and ventral (Day 0: 8.97 ± 0.18; Day 7: 4.10 ± 0.29) skin area. Our results provide data for a non-subjective determination of skin colour pattern and show that ECI offers a good index of the actual colour in a meaningful and objective way. © 2006 Elsevier B.V. All rights reserved.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Skin coloration patterns in fish are of great physiological, behavioural and ecological importance, can be considered as an index of animal welfare in aquaculture and as an important quality factor for the retail value, especially of red skinned fish. In the present study we developed an appropriate method for comparisons of the skin chromaticity parameters in wild (Pagrus pagrus, Pagrus caeruleostictus, and Dentex gibbosus) and farmed red skin Sparidae and investigated the effect of storage time on skin colour of farmed Pagrus pagrus. The three-dimensional characteristics of colour appearance (lightness - L*, hue - H°ab and chroma -Cab *) were calculated. A new index, named Entire Colour Index (ECI), was developed to express hue and chroma which as combined variables, cannot be considered separately. In all species there was a remarkable dorsoventral gradient in mean L* and H°ab, with the ventral area being statistically significant brighter than the dorsal one. ECI value was species specific but did not show any statistically significant dorsoventral gradient, with the exception of P. pagrus. Skin melanin and carotenoids content presented differences between the Pagrus and the Dentex species that may explain the differences in the observed chromaticity pattern. Storage time affected lightness and hue only in the dorsal skin area. However, the effect of storage on ice was better reflected in mean ECI value which showed a marked decrease from Day 3 to Day 7 in both the dorsal (Day 0: 8.96 ± 0.40; Day 7: 2.86 ± 0.29) and ventral (Day 0: 8.97 ± 0.18; Day 7: 4.10 ± 0.29) skin area. Our results provide data for a non-subjective determination of skin colour pattern and show that ECI offers a good index of the actual colour in a meaningful and objective way. © 2006 Elsevier B.V. All rights reserved. |
2005 |
Papandroulakis, N; Mylonas, C C; Maingot, E; Divanach, P First results of greater amberjack (Seriola dumerili) larval rearing in mesocosm Journal Article Aquaculture, 250 (1-2), pp. 155–161, 2005, ISSN: 00448486. @article{papandroulakis_first_2005, title = {First results of greater amberjack (Seriola dumerili) larval rearing in mesocosm}, author = {N Papandroulakis and C C Mylonas and E Maingot and P Divanach}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-27344450721&doi=10.1016%2fj.aquaculture.2005.02.036&partnerID=40&md5=85aba7698333eb1cdf77b60229a40d1b}, doi = {10.1016/j.aquaculture.2005.02.036}, issn = {00448486}, year = {2005}, date = {2005-01-01}, journal = {Aquaculture}, volume = {250}, number = {1-2}, pages = {155--161}, abstract = {Species diversification is considered a major approach for the sustainable development of aquaculture. The greater amberjack (Seriola dumerili) has particular characteristics-advantages making it an appropriate candidate: high growth rate, large size, and established worldwide market. In the present study, the mesocosm method for larval rearing was applied, since it has been shown to be effective in the larval rearing of several species so far. This method is a semi-intensive technology, based on daily exogenous food addition, but also having the capacity of some endogenous productivity. Greater amberjack eggs were obtained from wild-caught fish matured in captivity in 6 years, after induced spawning with implants containing gonadotropin-releasing hormone agonist (GnRHa). A total of 9800 eggs survived after embryo appearance and were incubated in a 40-m3 tank with natural seawater of 40 psu. Rearing lasted 40 days. After mouth opening on day 2 post hatching, exogenous feeding with rotifers, Artemia nauplii and inert feed was initiated, while endogenous produced copepods contributed as food for the larvae from day 7 post hatching onwards. During rearing, larvae grew with an exponential rate of 0.073 day -1 in terms of total length (TL), and reached 39.9 ± 5.4 mm and 0.5 ± 0.1 g body weight at the end of the trial. All larvae inflated their swim bladder and completed metamorphosis at about 5 mm and 8 mm TL, respectively. Schooling behavior was first observed when larvae reached 9-10 mm TL, while aggression against the smallest individuals was first noticed the same period. The final population of about 350 individuals (3.5% survival) was transferred at the end of the trial for subsequent on-growing. The results obtained indicate the reliability of the technology for the larval rearing of the greater amberjack, and also its appropriateness for diversification with difficult marine species. © 2005 Elsevier B.V. All rights reserved.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Species diversification is considered a major approach for the sustainable development of aquaculture. The greater amberjack (Seriola dumerili) has particular characteristics-advantages making it an appropriate candidate: high growth rate, large size, and established worldwide market. In the present study, the mesocosm method for larval rearing was applied, since it has been shown to be effective in the larval rearing of several species so far. This method is a semi-intensive technology, based on daily exogenous food addition, but also having the capacity of some endogenous productivity. Greater amberjack eggs were obtained from wild-caught fish matured in captivity in 6 years, after induced spawning with implants containing gonadotropin-releasing hormone agonist (GnRHa). A total of 9800 eggs survived after embryo appearance and were incubated in a 40-m3 tank with natural seawater of 40 psu. Rearing lasted 40 days. After mouth opening on day 2 post hatching, exogenous feeding with rotifers, Artemia nauplii and inert feed was initiated, while endogenous produced copepods contributed as food for the larvae from day 7 post hatching onwards. During rearing, larvae grew with an exponential rate of 0.073 day -1 in terms of total length (TL), and reached 39.9 ± 5.4 mm and 0.5 ± 0.1 g body weight at the end of the trial. All larvae inflated their swim bladder and completed metamorphosis at about 5 mm and 8 mm TL, respectively. Schooling behavior was first observed when larvae reached 9-10 mm TL, while aggression against the smallest individuals was first noticed the same period. The final population of about 350 individuals (3.5% survival) was transferred at the end of the trial for subsequent on-growing. The results obtained indicate the reliability of the technology for the larval rearing of the greater amberjack, and also its appropriateness for diversification with difficult marine species. © 2005 Elsevier B.V. All rights reserved. |
Lika, K; Papandroulakis, N Modeling feeding processes: A test of a new model for sea bream (Sparus aurata) larvae Journal Article Canadian Journal of Fisheries and Aquatic Sciences, 62 , pp. 425 – 435, 2005. @article{lika_modeling_2005, title = {Modeling feeding processes: A test of a new model for sea bream (Sparus aurata) larvae}, author = {K Lika and N Papandroulakis}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-21244489012&partnerID=40&md5=6d09799439dfccab3d0ab5e65d566178}, year = {2005}, date = {2005-01-01}, journal = {Canadian Journal of Fisheries and Aquatic Sciences}, volume = {62}, pages = {425 -- 435}, abstract = {An organism’s feeding rate is governed by constraints imposed by processes associated with consumption. We present a general feeding model that incorporates encounter, successful pursuit, handling, and digestion in one functional representation where we treat digestion as a parallel process. The model produces type II functional response curves. However, the asymptotic maximum feeding rate is determined by the sum of the time spent for handling and digesting a prey minus the gain in time, since the digestion process is parallel to the handling process. We use our model in combination with existing models of encounter, successful pursuit, and digestion to evaluate the feeding rate of fish larvae. We test the model against experimental data for sea bream (Sparus aurata) larvae and find a very close quantitative correspondence between predictions and experiments. Sensitivity analysis shows that for the early developmental stages, the model is sensitive to parameters related to the visual and locomotion abilities of larvae to detect and capture the prey. Later, when they establish these abilities, the choice of accepting or not the prey becomes more important. © 2005 NRC Canada.}, keywords = {}, pubstate = {published}, tppubtype = {article} } An organism’s feeding rate is governed by constraints imposed by processes associated with consumption. We present a general feeding model that incorporates encounter, successful pursuit, handling, and digestion in one functional representation where we treat digestion as a parallel process. The model produces type II functional response curves. However, the asymptotic maximum feeding rate is determined by the sum of the time spent for handling and digesting a prey minus the gain in time, since the digestion process is parallel to the handling process. We use our model in combination with existing models of encounter, successful pursuit, and digestion to evaluate the feeding rate of fish larvae. We test the model against experimental data for sea bream (Sparus aurata) larvae and find a very close quantitative correspondence between predictions and experiments. Sensitivity analysis shows that for the early developmental stages, the model is sensitive to parameters related to the visual and locomotion abilities of larvae to detect and capture the prey. Later, when they establish these abilities, the choice of accepting or not the prey becomes more important. © 2005 NRC Canada. |
Szisch, V; Papandroulakis, N; Fanouraki, E; Pavlidis, M Ontogeny of the thyroid hormones and cortisol in the gilthead sea bream, Sparus aurata Journal Article General and Comparative Endocrinology, 142 , pp. 186 – 192, 2005. @article{szisch_ontogeny_2005, title = {Ontogeny of the thyroid hormones and cortisol in the gilthead sea bream, Sparus aurata}, author = {V Szisch and N Papandroulakis and E Fanouraki and M Pavlidis}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-18144427445&partnerID=40&md5=95ebcdb3f57636df10429eeea10cafa2}, year = {2005}, date = {2005-01-01}, journal = {General and Comparative Endocrinology}, volume = {142}, pages = {186 -- 192}, abstract = {The aim of the study was to elucidate the pattern of changes in the whole body concentrations of thyroid hormones (TH) and cortisol in eggs, pre-larvae, and larvae in the gilthead sea bream, Sparus aurata. The ontogeny of these hormones was related to specific morphological characteristics that characterize early development. TH and cortisol were detected in substantial amounts in the eggs of sea bream. T3 concentration in eggs was found to be higher than that of T4 (T3, 4.02 ± 0.38 ng g-1; T4, 1.63 ± 0.28 ng g-1), as it is often observed in marine teleosts. T4 decreased until hatching (T4, 1.01 ± 0.58 ng g-1), while T3 reached a minimum at the time of first feeding (T3, 0.19 ± 0.02 ng g-1). As development proceeded, both hormones displayed a similar pattern of changes with increasing concentrations until the completion of metamorphosis (T3, 15.84 ± 2.92 ng g-1; T4, 9.78 ± 2.39 ng g-1), indicating that the hypothalamo-adenohypophysial-thyroid axis begins to function soon after first feeding. The pattern of changes of cortisol (F) concentration was almost parallel to that of T4, starting from 0.83 ng g-1 in eggs. Minimum F concentration was observed at hatching (0.39 ± 0.03 ng g-1) and maximum at melanophores and scale formation (14.82 ± 2.71 and 14.82 ± 3.12 ng g-1, respectively). Results provide data for the first time on the ontogeny of thyroid hormones and cortisol during the early development in sea bream and are in agreement with results in other fish species for an important action of TH during early development. © 2005 Elsevier Inc. All rights reserved.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The aim of the study was to elucidate the pattern of changes in the whole body concentrations of thyroid hormones (TH) and cortisol in eggs, pre-larvae, and larvae in the gilthead sea bream, Sparus aurata. The ontogeny of these hormones was related to specific morphological characteristics that characterize early development. TH and cortisol were detected in substantial amounts in the eggs of sea bream. T3 concentration in eggs was found to be higher than that of T4 (T3, 4.02 ± 0.38 ng g-1; T4, 1.63 ± 0.28 ng g-1), as it is often observed in marine teleosts. T4 decreased until hatching (T4, 1.01 ± 0.58 ng g-1), while T3 reached a minimum at the time of first feeding (T3, 0.19 ± 0.02 ng g-1). As development proceeded, both hormones displayed a similar pattern of changes with increasing concentrations until the completion of metamorphosis (T3, 15.84 ± 2.92 ng g-1; T4, 9.78 ± 2.39 ng g-1), indicating that the hypothalamo-adenohypophysial-thyroid axis begins to function soon after first feeding. The pattern of changes of cortisol (F) concentration was almost parallel to that of T4, starting from 0.83 ng g-1 in eggs. Minimum F concentration was observed at hatching (0.39 ± 0.03 ng g-1) and maximum at melanophores and scale formation (14.82 ± 2.71 and 14.82 ± 3.12 ng g-1, respectively). Results provide data for the first time on the ontogeny of thyroid hormones and cortisol during the early development in sea bream and are in agreement with results in other fish species for an important action of TH during early development. © 2005 Elsevier Inc. All rights reserved. |
2004 |
Mylonas, C C; Papandroulakis, N; Smboukis, A; Papadaki, M; Divanach, P Induction of spawning of cultured greater amberjack (Seriola dumerili) using GnRHa implants Journal Article Aquaculture, 237 (1-4), pp. 141–154, 2004, ISSN: 00448486. @article{mylonas_induction_2004, title = {Induction of spawning of cultured greater amberjack (Seriola dumerili) using GnRHa implants}, author = {C C Mylonas and N Papandroulakis and A Smboukis and M Papadaki and P Divanach}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-3142566876&doi=10.1016%2fj.aquaculture.2004.04.015&partnerID=40&md5=1d5f2c1607615bf23df2ad0e72aaa783}, doi = {10.1016/j.aquaculture.2004.04.015}, issn = {00448486}, year = {2004}, date = {2004-01-01}, journal = {Aquaculture}, volume = {237}, number = {1-4}, pages = {141--154}, abstract = {The objective of the current study was to examine the possibility of maturing Mediterranean greater amberjack (Seriola dumerili) in culture at two different facilities in Greece and inducing spawning using gonadotropin releasing-hormone agonist (GnRHa) implants. Males in both stocks (n=8) were in spermiating condition in mid June, though sperm motility was low ranging between 5% and 30%, while motility duration ranged between 2.1 and 2.5 min. Females of the first stock (n=4) at the same time had ovaries with either primary oocytes or early vitellogenic oocytes at advanced stages of atresia, indicating a failure in oogenesis. On the contrary, the only female of the second stock contained oocytes at all stages of oogenesis, including early final oocyte maturation (FOM; oocyte diameter 650 μm). Implantation with a GnRHa implant induced the first spawn about 36 h later. In the absence of another spawn, a gonadal biopsy was taken 15 days later, indicating the existence of more oocytes at post vitellogenesis and some with almost complete lipid droplet coalescence. A second GnRHa implantation at this time resulted in consecutive egg releases after 36 h, 4 and 5 days, with fertilized eggs only at 36 h and 5 days. The study underlines the existence of important reproductive dysfunctions of greater amberjack in captivity, and demonstrates that GnRHa implants can be used for the induction of multiple spawns of viable eggs. © 2004 Elsevier B.V. All rights reserved.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The objective of the current study was to examine the possibility of maturing Mediterranean greater amberjack (Seriola dumerili) in culture at two different facilities in Greece and inducing spawning using gonadotropin releasing-hormone agonist (GnRHa) implants. Males in both stocks (n=8) were in spermiating condition in mid June, though sperm motility was low ranging between 5% and 30%, while motility duration ranged between 2.1 and 2.5 min. Females of the first stock (n=4) at the same time had ovaries with either primary oocytes or early vitellogenic oocytes at advanced stages of atresia, indicating a failure in oogenesis. On the contrary, the only female of the second stock contained oocytes at all stages of oogenesis, including early final oocyte maturation (FOM; oocyte diameter 650 μm). Implantation with a GnRHa implant induced the first spawn about 36 h later. In the absence of another spawn, a gonadal biopsy was taken 15 days later, indicating the existence of more oocytes at post vitellogenesis and some with almost complete lipid droplet coalescence. A second GnRHa implantation at this time resulted in consecutive egg releases after 36 h, 4 and 5 days, with fertilized eggs only at 36 h and 5 days. The study underlines the existence of important reproductive dysfunctions of greater amberjack in captivity, and demonstrates that GnRHa implants can be used for the induction of multiple spawns of viable eggs. © 2004 Elsevier B.V. All rights reserved. |
Papandroulakis, N; Kentouri, M; Divanach, P Biological performance of red porgy (Pagrus pagrus) larvae under intensive rearing conditions with the use of an automated feeding system Journal Article Aquaculture International, 12 , pp. 191 – 203, 2004. @article{papandroulakis_biological_2004, title = {Biological performance of red porgy (Pagrus pagrus) larvae under intensive rearing conditions with the use of an automated feeding system}, author = {N Papandroulakis and M Kentouri and P Divanach}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-3042549353&partnerID=40&md5=f683700be4763c4677be7bf71340bc32}, year = {2004}, date = {2004-01-01}, journal = {Aquaculture International}, volume = {12}, pages = {191 -- 203}, abstract = {Pagrus pagrus is one of the promising species for the industry in the Mediterranean but its rearing is still far from satisfactory. In the present work, the conditions and results of larval rearing with the use of an automatic feeding system are presented. Eight populations were reared for 20 days with the ’pseudo green water’ methodology in two successive trials. Larvae were fed enriched rotifers during the entire rearing period, a mixed diet of rotifers and Artemia (Instar I when larvae reached 5 mm in length, replaced by Instar II after larvae reached 5.5 mm) and a formulated diet (after day 16 post hatching). A computerized system for feeding management was used. A total of 388,000 eggs were incubated and after 20 days, 237,973 larvae (TL = 6.96 ± 0.17 mm) were produced with a survival rate of 61.4 ± 6.3%. Individuals grew in terms of wet weight with an exponential rate of 0.167 ± 0.008 daily (R2 = 0.983) with no variations between replicates. Mean individual daily consumption at first feeding (day 4-post hatching), was 0.20 ± 0.06 mg of food (0.03 ± 0.01 dry weight), that is, 180-300 rotifers, while on day 20, consumption increased by 10 (2.081 ± 0.106 mg and 0.276 ± 0.014 in wet and dry weight, respectively). When compared with sea bream, consumption was higher by approximately 3-4-fold. The mean food conversion ratio of the experimental period was 4. In comparison with sea bream larviculture, food consumption of red porgy is higher, and a different feeding strategy is required to satisfy the requirements of the larvae. © 2004 Kluwer Academic Publishers.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Pagrus pagrus is one of the promising species for the industry in the Mediterranean but its rearing is still far from satisfactory. In the present work, the conditions and results of larval rearing with the use of an automatic feeding system are presented. Eight populations were reared for 20 days with the ’pseudo green water’ methodology in two successive trials. Larvae were fed enriched rotifers during the entire rearing period, a mixed diet of rotifers and Artemia (Instar I when larvae reached 5 mm in length, replaced by Instar II after larvae reached 5.5 mm) and a formulated diet (after day 16 post hatching). A computerized system for feeding management was used. A total of 388,000 eggs were incubated and after 20 days, 237,973 larvae (TL = 6.96 ± 0.17 mm) were produced with a survival rate of 61.4 ± 6.3%. Individuals grew in terms of wet weight with an exponential rate of 0.167 ± 0.008 daily (R2 = 0.983) with no variations between replicates. Mean individual daily consumption at first feeding (day 4-post hatching), was 0.20 ± 0.06 mg of food (0.03 ± 0.01 dry weight), that is, 180-300 rotifers, while on day 20, consumption increased by 10 (2.081 ± 0.106 mg and 0.276 ± 0.014 in wet and dry weight, respectively). When compared with sea bream, consumption was higher by approximately 3-4-fold. The mean food conversion ratio of the experimental period was 4. In comparison with sea bream larviculture, food consumption of red porgy is higher, and a different feeding strategy is required to satisfy the requirements of the larvae. © 2004 Kluwer Academic Publishers. |
Papandroulakis, N; Suquet, M; Spedicato, M T; Machias, A; Fauvel, C; Divanach, P Feeding rates, growth performance and gametogenesis of wreckfish (Polyprion americanus) kept in captivity Journal Article Aquaculture International, 12 , pp. 395 – 407, 2004. @article{papandroulakis_feeding_2004, title = {Feeding rates, growth performance and gametogenesis of wreckfish (Polyprion americanus) kept in captivity}, author = {N Papandroulakis and M Suquet and M T Spedicato and A Machias and C Fauvel and P Divanach}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-33749494732&partnerID=40&md5=452a6a205ec500f8fdcd8736ff3a50f1}, year = {2004}, date = {2004-01-01}, journal = {Aquaculture International}, volume = {12}, pages = {395 -- 407}, abstract = {Wreckfish (Polyprion americanus) is a panoceanic, antitropical distributed species. Despite the high market price, high growth rate, good quality flesh and the potential for aquaculture, research data are scarce. In this study, the growth performance and food intake was investigated in juvenile fish, while gametogenesis was studied in adult fish. Three groups were created from 19 individuals, which were collected during neustonic sampling, using fish aggregating devices, in association with floating objects and during tuna fishing with drift nets from Greece (Crete), Italy (Ionian Sea) and the Atlantic coast of France from September 1999 to March 2001. All individuals (initial weight between 0.5 g and 4.5kg) were reared in aquaculture facilities so as to monitor growth performance and food intake. Food (de-frozen fish - bogue, mackerel and squid - or moist pellets) was delivered ad libitum. Total length and wet weight were measured regularly. Daily food intake, the food conversion index and daily growth rate were calculated. Individuals, aging 0+, grew exceptionally fast, reaching 2.0kg (total length 50cm) in 12 months and 5.0kg (total length 65cm) in 24, while at later stages, the growth rate decreased and depended on the water temperature during rearing. Food consumption varied during the rearing period according to the developmental stage and the rearing conditions. The food conversion ratio ranged between 0.9 and 2.5 on dry weight basis during the period of the study. Gametogenesis was monitored in a separate stock of 15 individuals (11.7 ± 3.7 kg) by biopsis while blood samples were taken for steroid estimation. Increased oocyte diameter was observed in females from August to January, while plasma estradiol levels also increased from October to March. However, neither egg or sperm were collected from the stock. Young wreckfish presented a high growth rate in captivity, thus supporting the feasibility of the species for rearing. Further research, however, is required for the reproduction of the species. © 2004 Kluwer Academic Publishers.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Wreckfish (Polyprion americanus) is a panoceanic, antitropical distributed species. Despite the high market price, high growth rate, good quality flesh and the potential for aquaculture, research data are scarce. In this study, the growth performance and food intake was investigated in juvenile fish, while gametogenesis was studied in adult fish. Three groups were created from 19 individuals, which were collected during neustonic sampling, using fish aggregating devices, in association with floating objects and during tuna fishing with drift nets from Greece (Crete), Italy (Ionian Sea) and the Atlantic coast of France from September 1999 to March 2001. All individuals (initial weight between 0.5 g and 4.5kg) were reared in aquaculture facilities so as to monitor growth performance and food intake. Food (de-frozen fish - bogue, mackerel and squid - or moist pellets) was delivered ad libitum. Total length and wet weight were measured regularly. Daily food intake, the food conversion index and daily growth rate were calculated. Individuals, aging 0+, grew exceptionally fast, reaching 2.0kg (total length 50cm) in 12 months and 5.0kg (total length 65cm) in 24, while at later stages, the growth rate decreased and depended on the water temperature during rearing. Food consumption varied during the rearing period according to the developmental stage and the rearing conditions. The food conversion ratio ranged between 0.9 and 2.5 on dry weight basis during the period of the study. Gametogenesis was monitored in a separate stock of 15 individuals (11.7 ± 3.7 kg) by biopsis while blood samples were taken for steroid estimation. Increased oocyte diameter was observed in females from August to January, while plasma estradiol levels also increased from October to March. However, neither egg or sperm were collected from the stock. Young wreckfish presented a high growth rate in captivity, thus supporting the feasibility of the species for rearing. Further research, however, is required for the reproduction of the species. © 2004 Kluwer Academic Publishers. |
Papandroulakis, N; Kentouri, M; Maingot, E; Divanach, P Mesocosm: A reliable technology for larval rearing of Diplodus puntazzo and Diplodus sargus sargus Journal Article Aquaculture International, 12 , pp. 345 – 355, 2004. @article{papandroulakis_mesocosm_2004, title = {Mesocosm: A reliable technology for larval rearing of Diplodus puntazzo and Diplodus sargus sargus}, author = {N Papandroulakis and M Kentouri and E Maingot and P Divanach}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-33644987838&partnerID=40&md5=76b681983b3ee6f2281fdabaab3a4b3d}, year = {2004}, date = {2004-01-01}, journal = {Aquaculture International}, volume = {12}, pages = {345 -- 355}, abstract = {Species diversification is today considered as a major issue for the sustainable development of the Mediterranean aquaculture. For successful propagation of any species however, larval rearing is considered a bottleneck and therefore the development of appropriate tools is essential. Mesocosm is a semi-intensive technology that facilitates larval rearing of several species integrating principles of both intensive and extensive aquaculture, which solves biological problems and many of their technical, human and economical consequences. The extensive (and now even the semi-extensive) strategy is used in the most critical segments of the rearing process during the early developmental stages, when larvae are still extremely weak, sensitive to intensive environment, easily stressed and difficult to feed. The intensive strategy is used as soon as larvae are considered mature enough to be reared easily using classical methods. The technology was used for the rearing of two species, with potential for aquaculture, the sharpsnout seabream (Diplodus puntazzo) and the white seabream (Diplodus sargus sargus). Three groups of each species were monitored for a period of 50-70 days post hatching. Survival for both species was about 54% at the end of the trials. Sharpsnout seabream larvae reached 19.6 ± 0.9 mm total length and 107.2±31.9mg body weight 50 days post hatching. White seabream larvae 60 days post hatching reached 32.7 ± 2.7 mm total length and 450±70mg body weight. In order to verify the economical viability of the technology, the individual production cost for each species was estimated and reached €0.027 for white seabream and €0.043 for sharpsnout seabream. Results indicate the reliability of the technology for the larval rearing of the two species. © 2004 Kluwer Academic Publishers.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Species diversification is today considered as a major issue for the sustainable development of the Mediterranean aquaculture. For successful propagation of any species however, larval rearing is considered a bottleneck and therefore the development of appropriate tools is essential. Mesocosm is a semi-intensive technology that facilitates larval rearing of several species integrating principles of both intensive and extensive aquaculture, which solves biological problems and many of their technical, human and economical consequences. The extensive (and now even the semi-extensive) strategy is used in the most critical segments of the rearing process during the early developmental stages, when larvae are still extremely weak, sensitive to intensive environment, easily stressed and difficult to feed. The intensive strategy is used as soon as larvae are considered mature enough to be reared easily using classical methods. The technology was used for the rearing of two species, with potential for aquaculture, the sharpsnout seabream (Diplodus puntazzo) and the white seabream (Diplodus sargus sargus). Three groups of each species were monitored for a period of 50-70 days post hatching. Survival for both species was about 54% at the end of the trials. Sharpsnout seabream larvae reached 19.6 ± 0.9 mm total length and 107.2±31.9mg body weight 50 days post hatching. White seabream larvae 60 days post hatching reached 32.7 ± 2.7 mm total length and 450±70mg body weight. In order to verify the economical viability of the technology, the individual production cost for each species was estimated and reached €0.027 for white seabream and €0.043 for sharpsnout seabream. Results indicate the reliability of the technology for the larval rearing of the two species. © 2004 Kluwer Academic Publishers. |
2003 |
Pavlidis, M; Angellotti, L; Papandroulakis, N; Divanach, P Evaluation of transportation procedures on water quality and fry performance in red porgy (Pagrus pagrus) fry Journal Article Aquaculture, 218 , pp. 187 – 202, 2003. @article{pavlidis_evaluation_2003, title = {Evaluation of transportation procedures on water quality and fry performance in red porgy (Pagrus pagrus) fry}, author = {M Pavlidis and L Angellotti and N Papandroulakis and P Divanach}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-0037468983&partnerID=40&md5=80ecd722fd5c0e27d85db4c0de5ae08f}, year = {2003}, date = {2003-01-01}, journal = {Aquaculture}, volume = {218}, pages = {187 -- 202}, abstract = {The effect of stocking density (10, 20, 30, 40 kg/m3), water renewal (0% or 100% renewal rate per hour), hauling temperature (14, 19, 24 °C), salinity (20, 25, 30, 35, 40 psu), and use of anaesthesia (0, 10, 20, or 50 ppm ethynelglycol-monophenylether) prior to transportation on red porgy’s fry performance, liver glycogen, and water quality parameters was tested to evaluate transportation procedures in a promising candidate for aquaculture. Simulated transport was performed in plastic containers (volume 60 1) for 48 h. Water samples were taken at 4-h intervals after transport for the determination of pH, carbon dioxide (CO2), un-ionised ammonia (NH3) and ammonium (NH4 +). Additionally, liver samples were collected at 4 and 48 h for glycogen determination. There were no statistically significant fluctuations in dissolved CO2 concentration in all tested conditions. Stocking density did not affect NH3 and NH4 + average values and hepatic glycogen content in groups exposed to a water renewal rate of 100%, while increasing NH3 and NH4 + average values with increasing stocking density was observed in groups with no water renewal. Under the same stocking density, a significant change in NH3 and NH4 + fluctuations over the duration of the experiment was observed with concentrations increasing, with a mean exponential rate (± SD) of 0.060 ± 0.005 (NH3) and 0.062 ± 0.005 (NH4 +) per hour in groups with no water renewal, and -0.033 ± 0.004 (NH3) and -0.024 ± 0.007 (NH4 +) per hour in groups with 100% water renewal. Water temperature affected significantly the hepatic glycogen content and survival during transport. There was no significant effect of salinity and anaesthetic (except at a dose of 50 ppm) on fry survival and on the water quality parameters. It is suggested that red porgy should be transported in stocking densities of 20-25 kg/m3 and at a hauling temperature similar to that kept at the exporter’s fish rearing tanks (preferable 19 °C). Besides, it is recommended to avoid temperature differences between the hauling water and the water used for renewal during fry transportation. © 2003 Elsevier Science B.V. All rights reserved.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The effect of stocking density (10, 20, 30, 40 kg/m3), water renewal (0% or 100% renewal rate per hour), hauling temperature (14, 19, 24 °C), salinity (20, 25, 30, 35, 40 psu), and use of anaesthesia (0, 10, 20, or 50 ppm ethynelglycol-monophenylether) prior to transportation on red porgy’s fry performance, liver glycogen, and water quality parameters was tested to evaluate transportation procedures in a promising candidate for aquaculture. Simulated transport was performed in plastic containers (volume 60 1) for 48 h. Water samples were taken at 4-h intervals after transport for the determination of pH, carbon dioxide (CO2), un-ionised ammonia (NH3) and ammonium (NH4 +). Additionally, liver samples were collected at 4 and 48 h for glycogen determination. There were no statistically significant fluctuations in dissolved CO2 concentration in all tested conditions. Stocking density did not affect NH3 and NH4 + average values and hepatic glycogen content in groups exposed to a water renewal rate of 100%, while increasing NH3 and NH4 + average values with increasing stocking density was observed in groups with no water renewal. Under the same stocking density, a significant change in NH3 and NH4 + fluctuations over the duration of the experiment was observed with concentrations increasing, with a mean exponential rate (± SD) of 0.060 ± 0.005 (NH3) and 0.062 ± 0.005 (NH4 +) per hour in groups with no water renewal, and -0.033 ± 0.004 (NH3) and -0.024 ± 0.007 (NH4 +) per hour in groups with 100% water renewal. Water temperature affected significantly the hepatic glycogen content and survival during transport. There was no significant effect of salinity and anaesthetic (except at a dose of 50 ppm) on fry survival and on the water quality parameters. It is suggested that red porgy should be transported in stocking densities of 20-25 kg/m3 and at a hauling temperature similar to that kept at the exporter’s fish rearing tanks (preferable 19 °C). Besides, it is recommended to avoid temperature differences between the hauling water and the water used for renewal during fry transportation. © 2003 Elsevier Science B.V. All rights reserved. |
Machias, A; Somarakis, S; Papandroulakis, N; Spedicato, M -T; Suquet, M; Lembo, G; Divanach, P Settlement of the wreckfish (Polyprion americanus) Journal Article Marine Biology, 142 (1), pp. 45–52, 2003, ISSN: 0025-3162. @article{machias_settlement_2003, title = {Settlement of the wreckfish (Polyprion americanus)}, author = {A Machias and S Somarakis and N Papandroulakis and M -T Spedicato and M Suquet and G Lembo and P Divanach}, url = {http://link.springer.com/10.1007/s00227-002-0918-2}, doi = {10.1007/s00227-002-0918-2}, issn = {0025-3162}, year = {2003}, date = {2003-01-01}, urldate = {2020-08-18}, journal = {Marine Biology}, volume = {142}, number = {1}, pages = {45--52}, abstract = {The wreckfish (Polyprion americanus) is a panoceanic, long-lived, deep-water demersal species, characterized by an extended pelagic juvenile phase associated with floating objects. In the present study morphometric data from 435 specimens collected from Greece (Crete), Italy (Ionian Sea) and the Atlantic coast of France from September 1999 to March 2001 were analyzed to estimate the settlement size of the species and associated changes in morphology. The fishery sample included specimens from both the pelagic and the demersal stage. Length-at-settlement (TL50) and 95% confidence intervals were estimated by fitting a logistic function. Eleven morphometric characters were analyzed, and the existing inflection points, reflecting alterations in body shape, were defined: (1) iteratively, as the transition point, splitting the data set into two groups, for which the reduced major axis functions, between a character and total length, of the successive groups best fit (minimum sum of squares of residuals) the combined data set and (2) where the second derivative of the fitted third-order polynomial functions to morphometric ratios equaled zero. The main size range within which wreckfish settled was 56-65 cm, and the means of the inflection points defined by the two methods were 61 and 64 cm. These results indicate changes in functional morphology associated with settlement. The monitoring of wreckfish juveniles caught in the wild and kept individually in captivity showed changes in growth and food intake at approximately the estimated settlement length and suggested that temperature was the most likely factor triggering settlement.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The wreckfish (Polyprion americanus) is a panoceanic, long-lived, deep-water demersal species, characterized by an extended pelagic juvenile phase associated with floating objects. In the present study morphometric data from 435 specimens collected from Greece (Crete), Italy (Ionian Sea) and the Atlantic coast of France from September 1999 to March 2001 were analyzed to estimate the settlement size of the species and associated changes in morphology. The fishery sample included specimens from both the pelagic and the demersal stage. Length-at-settlement (TL50) and 95% confidence intervals were estimated by fitting a logistic function. Eleven morphometric characters were analyzed, and the existing inflection points, reflecting alterations in body shape, were defined: (1) iteratively, as the transition point, splitting the data set into two groups, for which the reduced major axis functions, between a character and total length, of the successive groups best fit (minimum sum of squares of residuals) the combined data set and (2) where the second derivative of the fitted third-order polynomial functions to morphometric ratios equaled zero. The main size range within which wreckfish settled was 56-65 cm, and the means of the inflection points defined by the two methods were 61 and 64 cm. These results indicate changes in functional morphology associated with settlement. The monitoring of wreckfish juveniles caught in the wild and kept individually in captivity showed changes in growth and food intake at approximately the estimated settlement length and suggested that temperature was the most likely factor triggering settlement. |
2002 |
Papandroulakis, Nikos; Papaioannou, Dimitris; Divanach, Pascal An automated feeding system for intensive hatcheries Journal Article Aquacultural Engineering, 26 (1), pp. 13–26, 2002, ISSN: 01448609. @article{papandroulakis_automated_2002, title = {An automated feeding system for intensive hatcheries}, author = {Nikos Papandroulakis and Dimitris Papaioannou and Pascal Divanach}, url = {https://linkinghub.elsevier.com/retrieve/pii/S0144860901000917}, doi = {10.1016/S0144-8609(01)00091-7}, issn = {01448609}, year = {2002}, date = {2002-03-01}, urldate = {2020-08-06}, journal = {Aquacultural Engineering}, volume = {26}, number = {1}, pages = {13--26}, keywords = {}, pubstate = {published}, tppubtype = {article} } |
Papandroulakis, N; Divanach, P; Kentouri, M Enhanced biological performance of intensive sea bream (Sparus aurata) larviculture in the presence of phytoplankton with long photophase Journal Article Aquaculture, 204 , pp. 45 – 63, 2002. @article{papandroulakis_enhanced_2002, title = {Enhanced biological performance of intensive sea bream (Sparus aurata) larviculture in the presence of phytoplankton with long photophase}, author = {N Papandroulakis and P Divanach and M Kentouri}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-0037148117&partnerID=40&md5=05a492b10b2b9875a20edf9b69f585b8}, year = {2002}, date = {2002-01-01}, journal = {Aquaculture}, volume = {204}, pages = {45 -- 63}, abstract = {Sea bream larvae were reared under intensive conditions either with (pseudo-green water technique) or without (clear water technique) the addition of phytoplankton in the rearing tanks, under 24- or 18-h photophases. Phytoplankton presence in the rearing medium resulted in 44 ± 17% survival and individuals of 2.0 ± 0.2 mg wet weight after 20 days of rearing. With the clear water method, both survival and growth decreased to 16 ± 6% and 1.1 ± 0.2 mg, respectively. The daily consumption rate (as milligram of carbon consumed per milligram body carbon) at the beginning of exogenous feeding was 0.5 day-1 for all experimental conditions. At later stages, individuals reared with phytoplankton present had a daily consumption rate of about 0.7 day-1, while those reared with the clear water technique presented consumption rates from 1.0 (for 24-h photophase) to 1.9 day-1 (for 18-h photophase). The mean food assimilation efficiency of the larvae, expressed as a Food Conversion Index (FCI), was between 6.3 ± 1.4 (for 18-h photophase) and 8.2 ± 1.2 (for 24-h photophase) for the individuals reared in the presence of phytoplankton. For larvae reared using the clear water technique, FCI was between 12.8 ± 2.4 (for 24-h photophase) and 20.1 ± 5.3 (for 18-h photophase). © 2002 Elsevier Science B.V. All rights reserved.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Sea bream larvae were reared under intensive conditions either with (pseudo-green water technique) or without (clear water technique) the addition of phytoplankton in the rearing tanks, under 24- or 18-h photophases. Phytoplankton presence in the rearing medium resulted in 44 ± 17% survival and individuals of 2.0 ± 0.2 mg wet weight after 20 days of rearing. With the clear water method, both survival and growth decreased to 16 ± 6% and 1.1 ± 0.2 mg, respectively. The daily consumption rate (as milligram of carbon consumed per milligram body carbon) at the beginning of exogenous feeding was 0.5 day-1 for all experimental conditions. At later stages, individuals reared with phytoplankton present had a daily consumption rate of about 0.7 day-1, while those reared with the clear water technique presented consumption rates from 1.0 (for 24-h photophase) to 1.9 day-1 (for 18-h photophase). The mean food assimilation efficiency of the larvae, expressed as a Food Conversion Index (FCI), was between 6.3 ± 1.4 (for 18-h photophase) and 8.2 ± 1.2 (for 24-h photophase) for the individuals reared in the presence of phytoplankton. For larvae reared using the clear water technique, FCI was between 12.8 ± 2.4 (for 24-h photophase) and 20.1 ± 5.3 (for 18-h photophase). © 2002 Elsevier Science B.V. All rights reserved. |
2001 |
Papandroulakis, N; Divanach, P; Anastasiadis, P; Kentouri, M The pseudo-green water technique for intensive rearing of sea bream (Sparus aurata) larvae Journal Article Aquaculture International, 9 , pp. 205 – 216, 2001. @article{papandroulakis_pseudo-green_2001, title = {The pseudo-green water technique for intensive rearing of sea bream (Sparus aurata) larvae}, author = {N Papandroulakis and P Divanach and P Anastasiadis and M Kentouri}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-0035741183&partnerID=40&md5=25026d07e6e77837a60e0648627158db}, year = {2001}, date = {2001-01-01}, journal = {Aquaculture International}, volume = {9}, pages = {205 -- 216}, abstract = {The "pseudo green water" technology for sea bream (Sparus aurata) larval rearing was evaluated by analyzing results of a 2-year study, performed in a pilot scale system. The technology is characterized by the daily addition of phytoplankton in the rearing tanks during the first month of rearing. Effects of egg origin, spawning season and initial larval density on the larval rearing were investigated. Fish reared in "pseudo green water" systems for 60 days, presented high biological performance in terms of survival (56 ± 16%), mean weight (62 ± 12 mg), total length (20 ± 1 mm), conformity with wild standard (88 ± 9%), and functional swim bladder (93 ± 4%). The results present homogenity between the categories (origin of eggs, time of spawning, initial egg density) studied, proving the stability of the technology.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The "pseudo green water" technology for sea bream (Sparus aurata) larval rearing was evaluated by analyzing results of a 2-year study, performed in a pilot scale system. The technology is characterized by the daily addition of phytoplankton in the rearing tanks during the first month of rearing. Effects of egg origin, spawning season and initial larval density on the larval rearing were investigated. Fish reared in "pseudo green water" systems for 60 days, presented high biological performance in terms of survival (56 ± 16%), mean weight (62 ± 12 mg), total length (20 ± 1 mm), conformity with wild standard (88 ± 9%), and functional swim bladder (93 ± 4%). The results present homogenity between the categories (origin of eggs, time of spawning, initial egg density) studied, proving the stability of the technology. |
2000 |
Maurizi, A; Diaz, J P; Divanach, P; Papandroulakis, N; Connes, R The effect of glycerol dissolved in the rearing water on the transition to exotrophy in gilthead sea bream Sparus aurata larvae Journal Article Aquaculture, 189 , pp. 119 – 131, 2000. @article{maurizi_effect_2000, title = {The effect of glycerol dissolved in the rearing water on the transition to exotrophy in gilthead sea bream Sparus aurata larvae}, author = {A Maurizi and J P Diaz and P Divanach and N Papandroulakis and R Connes}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-0034715335&partnerID=40&md5=2ad2493b26d28332d0f11b019e7a552a}, year = {2000}, date = {2000-01-01}, journal = {Aquaculture}, volume = {189}, pages = {119 -- 131}, abstract = {The effects of glycerol added to seawater at different concentrations were tested in monocultures of Chlorella minutissima and Brachionus plicatilis in mixed cultures of these two species and on starved or fed Sparus aurata larvae. Glycerol enhanced the growth of Chlorella and seemed to indirectly benefit the rotifers that feed on it. Its beneficial effect on gilthead sea bream prelarvae and larvae resulted in glycogen accumulation in the liver and absence of signs of cholestasis-like pathology. This effect varied according to the glycerol concentration in the water, to its addition timing and to light and feeding conditions. The gluconeogenic origin of the hepatic glycogen reserves is discussed, together with the mediating role of the food chain in glycerol larval assimilation. (C) 2000 Elsevier Science B.V.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The effects of glycerol added to seawater at different concentrations were tested in monocultures of Chlorella minutissima and Brachionus plicatilis in mixed cultures of these two species and on starved or fed Sparus aurata larvae. Glycerol enhanced the growth of Chlorella and seemed to indirectly benefit the rotifers that feed on it. Its beneficial effect on gilthead sea bream prelarvae and larvae resulted in glycogen accumulation in the liver and absence of signs of cholestasis-like pathology. This effect varied according to the glycerol concentration in the water, to its addition timing and to light and feeding conditions. The gluconeogenic origin of the hepatic glycogen reserves is discussed, together with the mediating role of the food chain in glycerol larval assimilation. (C) 2000 Elsevier Science B.V. |
Moschou, E A; Lasarte, Azpiroz U; Fouskaki, M; Chaniotakis, N A; Papandroulakis, N; Divanach, P Direct electrochemical flow analysis system for simultaneous monitoring of total ammonia and nitrite in seawater Journal Article Aquacultural Engineering, 22 , pp. 255 – 268, 2000. @article{moschou_direct_2000, title = {Direct electrochemical flow analysis system for simultaneous monitoring of total ammonia and nitrite in seawater}, author = {E A Moschou and U Azpiroz Lasarte and M Fouskaki and N A Chaniotakis and N Papandroulakis and P Divanach}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-0034128510&partnerID=40&md5=b82b0b1ee44766fb1f6d6e77b70ec3a9}, year = {2000}, date = {2000-01-01}, journal = {Aquacultural Engineering}, volume = {22}, pages = {255 -- 268}, abstract = {The design and the performance of a new portable flow analysis (FA) system for the continuous, fast and accurate measurement of total ammonia and nitrite content in non-filtered seawater samples is demonstrated. The complete system has been optimized to operate within the ammonia and nitrite concentration range of 0.05-10 ppm. The system offers good reproducibility (textless 5%) and stability (textless 0.02 ppm/h) at constant temperature, while the analysis time is in the order of 1.5-4 min depending on the sample analyzed. The analysis results of seawater samples obtained with the FA system were compared to that obtained with the standard colorimetric method and establish the suitability of the analyzer for the precise and continuous measurements of untreated samples for both in field and laboratory applications. In addition, its small size and weight offer the advantage of portability, while its datalogging capabilities also allow for independent ammonia and nitrite monitoring. (C) 2000 Elsevier Science B.V.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The design and the performance of a new portable flow analysis (FA) system for the continuous, fast and accurate measurement of total ammonia and nitrite content in non-filtered seawater samples is demonstrated. The complete system has been optimized to operate within the ammonia and nitrite concentration range of 0.05-10 ppm. The system offers good reproducibility (textless 5%) and stability (textless 0.02 ppm/h) at constant temperature, while the analysis time is in the order of 1.5-4 min depending on the sample analyzed. The analysis results of seawater samples obtained with the FA system were compared to that obtained with the standard colorimetric method and establish the suitability of the analyzer for the precise and continuous measurements of untreated samples for both in field and laboratory applications. In addition, its small size and weight offer the advantage of portability, while its datalogging capabilities also allow for independent ammonia and nitrite monitoring. (C) 2000 Elsevier Science B.V. |
Papandroulakis, N; Markakis, G; Divanach, P; Kentouri, M Feeding requirements of sea bream (Sparus aurata) larvae under intensive rearing conditions: Development of a fuzzy logic controller for feeding Journal Article Aquacultural Engineering, 21 , pp. 285 – 299, 2000. @article{papandroulakis_feeding_2000, title = {Feeding requirements of sea bream (Sparus aurata) larvae under intensive rearing conditions: Development of a fuzzy logic controller for feeding}, author = {N Papandroulakis and G Markakis and P Divanach and M Kentouri}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-0034008999&partnerID=40&md5=08b95efaa79a087e5c80a9df9872afc1}, year = {2000}, date = {2000-01-01}, journal = {Aquacultural Engineering}, volume = {21}, pages = {285 -- 299}, abstract = {Applied methods for larval rearing suffer from the difficulty of accurately predicting larvae quantitative feeding requirements for optimum growth. Even when known, requirements change according to the behavior of each population reared. Computer based feeding systems require tools for adapting the delivered amounts of food to the needs of the reared population. In this work the daily feeding requirements of sea bream (Sparus aurata) larvae were estimated, and based on these estimations a fuzzy logic controller (FLC) for feeding was designed and developed. Sea bream larvae were reared, in triplicate, under intensive conditions in a pilot scale rearing system for 20 days with the pseudo-green water method. Larvae reached 6.7 ± 0.6 mm (mean value and S.D.) at the end of the experimental period while the mean survival of the populations was 48.0 ± 12.6%. Consumption was 0.017 ± 0.009 mg of carbon per individual at first feeding and increased to 0.198 ± 0.032 mg at day 20 post-hatching. The findings were used for the development of a FLC for feeding that adapts the amount of food delivered to the larvae according to changes in the reared population. The FLC utilizes five linguistic variables describing the state of the population and a rule base composed of 316 rules. The developed FLC allows the use of computer based feeding systems during rearing of early larval stages. (C) 2000 Elsevier Science B.V.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Applied methods for larval rearing suffer from the difficulty of accurately predicting larvae quantitative feeding requirements for optimum growth. Even when known, requirements change according to the behavior of each population reared. Computer based feeding systems require tools for adapting the delivered amounts of food to the needs of the reared population. In this work the daily feeding requirements of sea bream (Sparus aurata) larvae were estimated, and based on these estimations a fuzzy logic controller (FLC) for feeding was designed and developed. Sea bream larvae were reared, in triplicate, under intensive conditions in a pilot scale rearing system for 20 days with the pseudo-green water method. Larvae reached 6.7 ± 0.6 mm (mean value and S.D.) at the end of the experimental period while the mean survival of the populations was 48.0 ± 12.6%. Consumption was 0.017 ± 0.009 mg of carbon per individual at first feeding and increased to 0.198 ± 0.032 mg at day 20 post-hatching. The findings were used for the development of a FLC for feeding that adapts the amount of food delivered to the larvae according to changes in the reared population. The FLC utilizes five linguistic variables describing the state of the population and a rule base composed of 316 rules. The developed FLC allows the use of computer based feeding systems during rearing of early larval stages. (C) 2000 Elsevier Science B.V. |
1997 |
Divanach, P; Papandroulakis, N; Anastasiadis, P; Koumoundouros, G; Kentouri, M Aquaculture, 156 , pp. 145 – 155, 1997. @article{divanach_effect_1997, title = {Effect of water currents on the development of skeletal deformities in sea bass (Dicentrarchus labtax L.) with functional swimbladder during postlarval and nursery phase}, author = {P Divanach and N Papandroulakis and P Anastasiadis and G Koumoundouros and M Kentouri}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-0030678081&partnerID=40&md5=ff2eb4edf54484b5987625d1168e5cac}, year = {1997}, date = {1997-01-01}, journal = {Aquaculture}, volume = {156}, pages = {145 -- 155}, abstract = {Lordosis in reared sea bass was previously related either to the absence of swimbladder, or to bad or late inflation of this organ when damages were irreversible. Our results prove that these explanations are insufficient and that similar deformations may occur frequently in fry with functional swimbladder during the early weaning phase, if currents in tanks are higher than 10 cm s-1.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Lordosis in reared sea bass was previously related either to the absence of swimbladder, or to bad or late inflation of this organ when damages were irreversible. Our results prove that these explanations are insufficient and that similar deformations may occur frequently in fry with functional swimbladder during the early weaning phase, if currents in tanks are higher than 10 cm s-1. |