Key research areas
Sex differentiation, gametogenesis, reproductive cycles, induced spawning, sperm quality
The facilities include tanks of various volumes (3 x 35 m3, 7 x 15 m3, 2 x 10 m3, 8 x 5 m3and 14 x 2 m3) for the maintenance of breeders of different species. All but the smallest tanks can operate either in flow-through or recirculation mode, and are equipped with temperature and photoperiod control using LED lights. The species maintained include European sea bass (Dicentrarchus labrax), gilthead sea bream (Sparus aurata), sharpsnout sea bream (Diplodus puntazzo), shi drum (Umbrina cirrosa), meagre (Argyrosomus regius), and greater amberjack (Seriola dumerili). Eggs are maintained in temperature-controlled egg incubators, and larvae can be maintained until the end of yolk absorption.
Recently, a new Recirculation Aquaculture System (RAS) has been designed (StavRAS Aquatic Solutions Ltd, Cyprus) for the maintenance of our marine broodstock, and the first system has been installed and is in operation since August 2023. The system is equipped with state-of-the-art filters (mechanical, biological, CO2 stripping, Ozonation, UV disinfection, etc.) that will provide optimal water quality for the reproductive performance of the fish, while at the same time will ensure that no pathogenic organism can be multiplied and cause an infection. In the next few years, three more such systems will be installed in the facility, to house the majority of our broodstocks.
A wet laboratory is used for the sampling (blood, gonadal biopsies and tissue extraction) and the initial evaluation of gamete and egg quality obtained from the various experimental and production broodstocks. Light compound and stereo microscopes are used to evaluate the quality of oocytes obtained via ovarian biopsies, in order to monitor the stage of oogenesis and select females for hormonal spawning induction. A computer-assisted sperm analysis (CASA) system is available for the evaluation of sperm quality, looking at sperm motility characteristics.
Supporting the facility is an analytical laboratory equipped with a variety of equipment for the study of reproductive biology and endocrinology. Hormonal analyses are curried out using ELISAs, and include the sex steroid hormones, gonadotropins and gonadotropin releasing hormone agonists (GnRHa). Histological evaluations are done using methacrylate resin and various stains. Controlled temperature incubators are used for the evaluation of egg and larval quality using the micro-titer plate method. A spectrophotometer is used to monitor water quality in the broodstock tanks. The laboratory is also equipped for the production of polymer-based, controlled-release devices for GnRHa, used for the induction of spawning and enhancement of sperm production (EVAc implants and PLGA microspheres).
- Protocol for the evaluation of egg and larval quality using 96 well microtiter plates
- Protocol for the induction of spawning in meagre (Argyrosomus regius)
- Protocol for the collection of eggs and evaluation of quality using a 48-well microtiter (mct or ELISA) plate