Effect of dietary supplementation of Padina astraulis (Hauk) extract on biochemical response and digestive enzyme activities of grey mullet, Mugil cephalus (Linnaeus)

Abstract

This study was aimed to assess the effect methanol extract from Padina astraulis (Hauk) on biochemical response and digestive enzyme activities in grey mullet Mugil cephalus (Linnaeus). A control diet without and a series of experimental diets were prepared with supplementation of P.astraulis extract (PE diet) at the inclusion level of 5, 10 and 15 g kg-1 diet. Three hundred sixty grey mullet with an initial mean weight of 0.82 g were randomly distributed into twelve tanks and fed twice a day (09:00 and 17:00) for 60 days. After 60 days of the feeding trial, no different was observed in survival between control and PE supplemented groups (P>0.05).Dietary PE significantly increased serum total protein, globulin levels and amylase, lipase and protease enzyme activities in treated fish (P<0.05). Moreover, there was significant decline (P<0.05) in cholesterol, glucose and triglyceride levels in those fish which received PE diet over the control. The present study elucidates the suitability of P. astraulis extract as a novel dietary supplement in grey mullet diet for improving metabolism of lipid and carbohydrate and enhancing digestive enzyme activities in grey mullet.