Dietary protein requirement of juvenile mud crab Scylla paramamosain

Abstract This experiment was carried out to investigate the optimal dietary protein levels for juvenile Scylla paramamosain. Six isoenergtic and isolipidic semi-purified diets were formulated with graded protein levels, and the final protein concentrations were 32.69%, 38.54%, 42.92%, 49.89%, 52.09% and 60.07%, respectively. Each diet was offered to triplicate groups of 28 mud crabs (initial weight 0.04 ± 0.001 g, carapace length 3.3 ± 0.05 mm) for 8 weeks. The results showed that the mud crabs fed diets with 32.69% and 60.07% protein had significantly lower survival than those in other treatments (p   .05). According to the polynomial regression analysis, 47.06% dietary protein was required for juvenile S. paramamosain to obtain maximum growth rate.