Diet of the Atlantic sailfish Istiophorus albicans (Latreille, 1804) caught in Coastal marine waters of Côte d’Ivoire, West Africa

Abstract

Seasonal and size-related patterns in feeding habits of the Atlantic sailfish Istiophorus albicans in coastal marine waters of Côte d’Ivoire (a West African country) were investigated along with food composition. The study was carried out from December 2015 to November 2016. Fish size ranged from 150 cm to 195 cm LJFL (lower-jaw fork length). The fish were caught with gillnets deployed over the continental shelf by artisanal fishers. Of the stomachs examined, 32.65% contained at least one prey item while 21.43% contained Fish crystalline lens and Cephalopod crystalline lens as well as remaining Fish bones and Cephalopod beaks. Additionally, 45.92% of stomachs examined were empty or contained digestive fluids. No seasonal and size-related patterns were however found in the occurrence of non-empty stomachs, probably as a result of predominance of empty stomachs. The overall diet composition in terms of numerical importance was 86% Fish, of which flying gurnard, Dactylopterus volitans (Linnaeus, 1758) were the commonest (75.40%), far exceeding even all the Scombrids lamped together (1.84%). Prey size range was quite extended as it varied from smaller Cephalopod prey (3.1 – 3.8 cm ML, mantle length) to relatively larger Fish prey (43.5 cm SL, standard length), suggesting that the Atlantic sailfish could virtually feed on prey of various size.