Evaluation Of Enteromorpha Prolifera As A Feed Component In Large Yepplow Croaker (Pseucosciaena Crocea) Diets

A 9-week feeding trial was conducted to investigate the effects of dietary Enteromorpha prolifera on growth performance and body composition of juvenile large yellow croaker (Pseudosciaena crocea) (11.41±1.59 g) in floating sea cages (1.5 x 1.5 x 2.0 m). Four isonitrogenous and isoenergetic diets were formulated to contain graded levels (0,5,10 and 15%) of Enteromorpha prolifera. Survival ranged from 98.7% to 99.7%, and was independent of dietary treatment (P>0.05). There were no significant differences in the feeding rate (FR) among dietary treatments (P>0.05). The specific growth rate (SGR) increased with increasing levels of Enteromorpha prolifera. When the supplementation of Enteromorpha prolifera was more than 5%, SGR was significantly higher compared to the control group (0%). The feed efficiency ratio (FER) in fish fed diet with 5% Enteromorpha prolifera (diet 2) was higher than the other groups, while fish fed the diet with 10%(diet 3) was the lowest (P<0.05). The protein retention (PR) decreased as the level of Enteromorpha prolifera increased in diets (5,10, and 15%). The protein body content displayed a similar trend to that of PR. No significant difference was observed in body moisture and ash among the dietary treatments. An increase in minerals of potassium (K), magnesium (Mg) and sodium (Na) in body was observed with increase of dietary seaweed concentrations. On basis of the SGR and FER, supplementation levels of Enteromorpha prolifera can reach at least 15% without affecting the growth and still maintain a high survival rate for juvenile large yellow croaker.