Relationships between diet and environmental parameters for cassava croaker in continental shelf waters of Côte D’Ivoire

Abstract

Identifying the dietary niche of aquatic predators is essential to understanding the structure of aquatic ecosystems. Dietary analysis is key to formulation of a feeding strategy and the breadth of a predator’s diet. The objective of this study was to evaluate the diet of cassava croaker (Pseudotolithus senegalensis) off the Ivorian coast, characterised by different hydrological regimes, as an entry point for this species’ acclimation. Diets and feeding intensities of cassava croaker were evaluated through analysis of the stomach contents of fish collected monthly, off the Ivorian continental shelf water, during January 2014 to December 2015. A total of 1, 238 fish stomachs were analysed, 551 (44.50%) emptied and 687 (55.50%) contained preys. Six different prey species belonged to three groups, namely crustaceans, fishes and cephalopods and were identified as cassava croaker stomach contents. The preponderance index indicated that crustaceans were the main food of cassava croaker. Crustaceans dominated 85% frequency of occurrence. The diets varied significantly with fish size; young ones (months after) preyed on crustaceans; whereas larger fishes (LS > 20.45 cm) preyed on both crustaceans and fishes.