Characterization of feeding habits, prey diversity and diet overlap of two sympatric species: Bronze catfish, Netuma bilineata (Valenciennes, 1840) and blacktip sea catfish, Plicofollis dussumieri (Valenciennes, 1840) in the northern Arabian Sea

Abstract

Summary This study describes the diet composition, diet overlap and prey diversity in two economically and ecologically important marine catfish species: the bronze catfish (Netuma bilineata) and the blacktip sea catfish (Plicofollis dussumieri) collected between January and December 2015 from the northern Arabian Sea coast of Pakistan. Stomach data of 342 bronze catfish and 283 blacktip sea catfish were examined. Diet composition and feeding strategy of each species by identification of stomach contents were weighed and enumerated. Both species primarily consumed teleosts, Brachyura and small amounts of a wide variety of prey items; however, specialization was a more common trait for the bronze catfish than for the black tip sea catfish. The Morisita-Horn index showed considerable diet overlap in percentage of mean weights (0.847) than in numbers (0.612) between co-prey pairs of both species. The highest Bray-Curtis similarity between the southwest monsoon (SWM) and south inter monsoon (SIM) was observed in bronze catfish and lowest between autumn inter monsoon (AIM) seasons in both species. While Bray-Curtis dissimilarity was observed, both species share diet niches and diet overlap. The present study evaluation of the feeding strategy and potential competition between two sympatric species of marine catfishes can provide the framework for their conservation and management in the region.