The complete life cycle in captivity of the spider crab, Maja brachydactyla, Herbst 1788

The present research describes the complete life cycle in captivity, including spawning, larval culture and fattening of juveniles until commercial size. Additionally, size, weight and age at each moulting stage were recorded, as well as zoeas biochemical composition. The most significant results obtained were as follows. Embryonic development lasted for 33days. Each female had between three and five spawns, separated by 4-5days each. Larval culture lasted for 20days at 14-17 degrees C. The zoeas turn to megalopa at similar to 11days after hatch/DAH), and from megalopa to juvenile at similar to 20 DAH. Average survival was similar to 13%. Juvenile growth rate was higher during the first 8months (0.22%-0.46% bw/day), and then gradually decreased when changing from live to frozen diets. Survival during the fattening phase was 63%. The final moult occurs at 450 DAH, when males and females have a carapace total length of 12.38+1.23 and 13.57+1.23cm, respectively, and 541.56+104.26 and 670.68+162.6g in total weight respectively. Biochemical composition of cultured zoeas showed a high amount of phospholipids and long-chain fatty acids, docosahexaenoic acid (DHA), eicosapentaenoic acid (EPA) and arachidonic acid (ARA). Low survival rates in larval culture and especially after passing to the benthic life style are the main problems regarding spider crab culture, and need to be improved.