IMMUNOMODULATORY EFFECTS OF DIETARY INTAKE OF CHITOSAN ON NON-SPECIFIC IMMUNE RESPONSE OF MUGIL CEPHALUS CHALLENGED WITH AEROMONAS HYDROPHILA

Abstract

The aim of this study was to observe the effect of dietary chitosan on Mugil cephalus non-specific immunity. M. cephalus with an average weight of 45±2 g were fed diet for 70 days containing control, and control diet with 1%, 2%, and 5% chitosan, respectively. On days 30 and 58, fish from each treatment group (1%, 2%, and 5% chitosan group) were challenged with Aeromonas hydrophila to study response of chitosan-fed fish to the bacterial challenge. When compared to the control group, the chitosan fed (2%) groups had higher phagocytic index, phagocytic ratio, and serum bactericidal activity (P≤0.05). When the fish in all treatments were given A. hydrophila intraperitoneally, the relative percentage survival (RPS) was higher in the chitosan (2%) category (P≤0.05) than in the other treatments. The control group performed poorly in all non-specific immune response assays, which was accompanied by a decline in survival and growth rates. Thus, including chitosan at a concentration of 2% in a fish's diet improved non-specific immunity, decreased fish mortality, and improved fish growth.