Dietary biofloc supplementation in black tiger shrimp, Penaeus monodon : effect on immunity, antioxidant and metabolic enzyme activities.

Abstract

A 60-day indoor experiment was conducted tostudy the effect of dietary supplementation of bio-floc on metabolic enzyme activities and immuneresponses inPenaeus monodonjuveniles. Bioflocdeveloped in indoor fibreglass-reinforced plastic(FRP) tanks (1000 L) was used as dietary supple-ment inP. monodon(2.90 0.10 g) reared in1000-L FRP tanks. Graded level of dried bioflocwas included in shrimp basal diets, 0% (control,B0), 4% (B4), 8% (B8) and 12% (B12). The levelof metabolic enzymes like malate dehydrogenase(MDH), aspartate aminotransferase (AST) and ala-nine aminotransferase (ALT) was not significantlydifferent with control up to 8% dietary supplemen-tation. A higher level of total haemocyte count(THC) was noticed in B8 (22.16 2.179106cells mL 1) and B4 (21.11 0.569106cellsmL 1)comparedwithcontrol,C(14.61 2.749106cells mL 1). Biofloc-supple-mented groups recorded significantly higher(P<0.05) serum SOD and catalase activity(P<0.01) in comparison with control. The groupsfed with 4% dietary biofloc supplement recordedhighest relative percentage survival (RPS), 45%after challenge withVibrio harveyifollowed by36% and 27% RPS in B8 and B12 groups. Basedon these results, it can be concluded that supple-mentation of biofloc even at 4% level in the feedimproves immune responses and metabolic activi-ties in black tiger shrimp juveniles.