A Reproduction and physiology
Fish nutrition and feeding
SELFDOTT proposes to implement knowledge already obtained on the artificial control of reproduction of the Atlantic bluefin tuna (BFT), Thunnus thynnus, to obtain viable eggs, and study embryonic and larval development for the production of fry (juveniles). At the same time, suitable and environmentally performing feeds for the growout of BFT will be developed, thus reducing or eliminating the practice of raw fish importation and feeding by the fattening industry. Wild juvenile and mature BFT will be reared in captivity at two sites in the Mediterranean, and will be used to study puberty, gametogenesis, and the influence of diet on reproductive maturation and gamete quality. Mature fish will be induced to spawn using hormone implants and the eggs will be collected using devices designed specifically for cages. A population genetic analysis will be conducted to identify the origin of the broodstock in relation to known wild stocks. Parentage analysis will allow estimating the contribution of successful spawners to the reproduction, and the use of many markers on the resulting crosses will allow the creation of a genetic map. To establish the knowledge-base for controlled development of BFT larvae, the mesocosm and artificial larval rearing methods will be employed. The ontogenesis of essential biological functions will be studied, including environmental perception, digestion, immunity and behaviour. A protocol for the commercial-scale larval rearing of BFT will be recommended at the end of the project. Whole body and stomach composition of wild fish will be analyzed and serve as a guide to formulate nutritionally complete artificial feeds for BFT. Juveniles will be captured from the wild, adapted to captive conditions and used to carry out weaning and feeding experiments, using moist and dry pelleted diets. The environmental impact of the formulated feeds will be examined and compared to existing raw-fish practises. SELFDOTT will produce the basic knowledge necessary for the development of a self-sustained aquaculture industry for the BFT in the Mediterranean, thus enhancing the competitiveness of the EU aquaculture industry, while at the same time reducing the pressure on the wild BFT stocks and ensuring the conservation and recovery of this magnificent fish.