Effects of dietary lipid levels on growth, body composition and antioxidants of clamworm (Perinereis aibuhitensis)

To determine the effects of dietary lipid levels on growth performance, body composition and antioxidant parameters of clamworm (Perinereis aibuhitensis), 1050 clamworms were fed diets with seven lipid levels (2.37%, 4.35%, 6.29%, 8.41%, 10.31%, 12.29% and 14.33%, named L2.37, L4.35, L6.29, L8.41, L10.31, L12.29 and L14.33, respectively) for 10 weeks. Each diet was randomly assigned to triplicate groups of 50 clamworms. The results showed that the growth performance and protein efficiency ratio were significantly affected by the lipid levels. Clamworms fed L8.41 diet exhibited higher growth performance than others and the maximum specific growth rate can be possibly obtained when the diets were supplemented with 7.54% lipid level. The dietary lipid levels had significant influences on the whole body crude protein, crude lipid, moisture contents and ash profile of P. aibuhitensis. The eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) were also enhanced with increasing dietary lipid levels in whole body analyses. The contents of malonaldehyde (MDA) and lipid peroxidation (LPO) in clamworms increased significantly with increasing dietary lipid levels. Meanwhile, the activities of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPX) and total autioxidative capacity (T-AOC) tended to strengthen with dietary lipid levels increasing from 2.37% to 10.31% (except the GPX with 12.29% dietary lipid levels), and weaken with dietary lipid levels increasing from 10.31% to 14.33%. These results demonstrated that a proper dietary lipid level of 7.54%-10.31% could maintain solid growth performance and antioxidant capacity of juvenile P. aibuhitensis.