The effects of using crab zoeae (Maja brachydactyla) on growth and biochemical composition of Octopus vulgaris (Cuvier 1797) paralarvae

Octopus vulgaris farming at large scale can only be attained using live prey during the paralarvae stage. Presently, only Artemia complies with this requirement. Nevertheless, its sole use delivers poor paralarvae growth and survival. Some species of marine zooplankton are better prey for marine fish larvae compared to Artemia, since its composition is richer in several important nutritional components. Among these are phospholipids and specific fatty acids, namely docosahexaenoic acid, eicosapentaenoic acid and arachidonic acid. During the present experiment, octopus paralarvae were fed a co-feeding scheme of spider crab (Maja brachydactyla) zoeae and Artemia (1:2, Artemia/Crab zoeae). The use of spider crab zoeae was justified by their availability in commercial facilities, where adult spider crabs are maintained to be sold to the public. There, fecund and spawning females are present in large numbers, and zoeae availability is often high and implies no production or zoeae collection costs. O. vulgaris paralarvae fed on Artemia and crab zoeae grew larger (3.00 ± 0.56 mg dw−1) after 30 days, compared to previous published papers. Also, the paralarvae lipid content was substantially enhanced in highly unsaturated fatty acids and phospholipids. However, survival after 30 days was still very low (1.75 % after 30 days) and needs to be greatly improved.Publicado

Nutrition as a key factor for Cephalopod Aquaculture

Cephalopods are fast-growing animals, active swimmers and top predators, which require substantial amounts of food. As such, they show high metabolic rates dependent on a carnivorous diet, thus hypothetically linked to a predominant amino acid metabolism. Their body composition is mainly constituted by high levels of total protein, and their lipids, although quantitatively low, reveal the presence of substantial amounts of long-chain polyunsaturated fatty acids. All in all, little is known about their nutritional requirements, especially during the early stages, very prone to high mortalities under culture. This chapter is a brief account of key information concerning relevant points linked to the nutritional requirements that cephalopods have for proteins, lipids, carotenoids, carbohydrates, minerals and vitamins. Moreover, some considerations on populational metabolism are also presented.Peer reviewe