Study on stomach contents of sailfin silversides, Telmatherina sarasinorum Kottelat 1991, in Matano Lake, South Sulawesi, Indonesia

Abstract

The silverside sailfin, Telmatherina sarasinorum Kottelat 1991, is an endemic fish that lives in Matano Lake, South Sulawesi. The purpose of this study is to analyze the stomach contents of T. sarasinorum. The study was conducted from March 2018 to February 2019. Samples were collected using bag nets (with mesh size of 0.5 inches). The fish collected (N=2124 individuals) consisted of 1318 male fish and 806 female fish with a total body length ranging from 30.1 to 89.85 mm. Gastrointestinal contents were analyzed using Index of Preponderance (IP), niche breadth, and feeding overlap. The data was processed based on gender temporally and spatially. The results showed that the fish’s main diet was insects (IP 71.04% in males, 95.40% in females) and fish eggs (IP 26.04% in males, 3.71% in females). The value of niche breadth in males and females was low, ranging from 0.0005-0.2291 (male) and 0.0048-0.2295 (female) indicating that this species was a fish that specializes in utilizing food. There was a high competition for food between males and females which was indicated by a fairly large overlap value, which was 0.7767 temporally and 0.7725 spatially.