P. Akbary - Fisheries Group,Faculty of Marine Sciences, Chabahar Maritime University, Chabahar, Iran
N. Shahraki - Fisheries Group,Faculty of Marine Sciences, Chabahar Maritime University, Chabahar, Iran

This research aimed to assess the effect methanol extract from Padina astraulis (Hauk , ۱۸۸۷) on biochemical response and digestive enzyme activities in grey mullet, Mugil cephalus (Linnaeus, ۱۷۵۸). A control diet without and three other empirical regimens were prepared with the addition of of P.astraulis extract (PE diet) at the incorporation levels of ۵, ۱۰ and ۱۵ g kg-۱ diet, respectively. Three hundred sixty grey mullet with an introductory mean weight of ۰.۸۲ g were randomly dispersed into twelve fish tanks and fed twice a day (۰۹:۰۰ and ۱۷:۰۰) for ۶۰ days. After ۶۰ days of the feeding trial, no significantly different was noticed in terms of survival rate between control and the groups supplemented with PE (p>۰.۰۵). Dietary PE significantly increased serum total protein, globulin levels and amylase, lipase and protease enzyme activities in treated fish (p<۰.۰۵). Moreover, there was considerable decline (p<۰.۰۵) in cholesterol, glucose and triglyceride levels in those fish which received PE diet over the control. The current research illustrates the appropriateness of P. astraulis extract as a novel dietary additive in grey mullet diet for improving metabolism of lipid and carbohydrate and enhancing digestive enzyme activities in grey mullet.

Padina astraulis, Mugil cephalus, Biochemical response, Digestive enzymes, Dietary supplement