Decreasing dietary lipids improves larval survival and growth of Japanese eel Anguilla japonica

• Published in: Fisheries science Vol. 80; no. 3; pp. 581 - 587
• Main Authors: Furuita, Hirofumi, Murashita, Koji, Matsunari, Hiroyuki, Yamamoto, Takeshi, Nagao, Jiro, Nomura, Kazuharu, Tanaka, Hideki
• Format: Journal Article
• Language: English
• Published: Tokyo Springer Japan 01.05.2014; Springer Nature B.V
• Subjects: Anguilla japonica; Animal reproduction; Aquaculture; Biomedical and Life Sciences; Diet; Eggs; Enzymes; Experiments; Feeds; Fish; Fish & Wildlife Biology & Management; Fisheries; Fishery sciences; Food Science; Freshwater & Marine Ecology; Ingredients; Laboratories; Larvae; Life Sciences; Lipids; Marine; Nutritive value; Original Article; Peptides; Research centers; Sharks; Studies; Survival; Japan; Diet; Larvae; Lipids
• ISSN: 0919-9268; 1444-2906
• DOI: 10.1007/s12562-014-0713-2

Shark eggs-based diet is the only diet by which eel larvae can grow to glass eels in captivity. However, the high level of lipids in the diet is suggested to negatively affect eel larvae. This paper examines the effect of defatted shark eggs (DSE) and hen egg yolk (HY) on growth and survival of larvae of Japanese eel Anguilla japonica . Lyophilized shark egg and commercial HY were defatted with n -hexane, and four experimental diets were prepared using both defatted and untreated shark eggs and HY. Larvae were reared for 3 weeks by feeding the experimental diets. The highest survival rate was observed in the larvae fed DSE, and larvae fed HY showed the lowest survival rate. The best growth was found in larvae fed DSE, followed by shark eggs and defatted HY, and the worst growth was in HY-fed larvae. These results show that decreasing dietary lipids improves the nutritional value of both shark eggs and HY for eel larvae. Regulation of the dietary lipid level may positively affect the larval performance of eels by combination of ingredients with a low lipid content.