Gut Content Analysis of Indian Mackerel (Rastrelliger kanagurta)

Abstract

Analysis of gut content is widely used to ascertain the food and feeding habit of fish species. Diets of fishes represent an integration of many important ecological components that included behavior, condition, habitat use, energy intake and inter/intra specific interactions. The food and feeding of the Indian mackerel Rastrelliger kanagurta [1]was studied based on 42 fishes ranging in size from 13 to 25 cm Total Length (TL), collected by purse seiner during the summer period (February to April), the period in which the fish is available along the Massawa Coast. The methodologies followed in this study are Occurrence method for recording the stomach contents; Gravimetric method to evaluate the net weight of individuals per stomach in each food category [2,3]; Volumetric (Displacement) method used for estimation of various food items [4] and also Index of Preponderance used to evaluate the relative value of different organisms in the diet [5]. There was a preponderance of empty stomachs is noticed. The dominant food item observed was Copepod. The fish (Bregmaceros sp.), Sand and fish scale also formed part of the stomach content.