Food and feeding of the ribbonfish Trichiurus lepturus Linnaeus off Karnataka, south-west coast of India

Abstract

Trichiurus lepturus samples landed by trawl boats at Mangalore Fishing Harbour were collected regularly from January, 2008 to December, 2012. Stomach of 4,581 ribbonfishes ranging in size from 40 to 110 cm total length (TL) were analysed to study their feeding habits. Prey mainly belonged to three major taxonomic groups i.e., fishes, crustaceans and cephalopods. Index of relative importance (IRI) values were higher for fishes followed by crustaceans and cephalopods. Acetes sp., Stolephorous devisi, Loligo sp., Saurida tumbil, Sardinella longiceps and Decapterus russelli were the major food items. Juveniles of T. lepturus and unidentified fish as well as shrimp remains were found occasionally in the gut indicating cannibalistic behaviour. Higher feeding intensity in terms of stomach fullness index (SFI) was observed during April, June and October and lower values during November and December. The monthly change in the empty stomach ratio (ESR) varied from 66.58% in September to 79.14% in June. Generally higher values of ESR were noticed during March to August and lower values during September to February.