Habits and food ethology of Synodontis membranaceus Geoffroy Saint-Hilaire, 1809 (Siluriformes, Mochokidae) in the Bagoué River (Côte d’Ivoire)

Abstract

The diet of Synodontis membranaceus Geoffroy Saint-Hilaire, 1809 was studied in the Bagoue River (Cote d’Ivoire). A total of 255 stomachs were examined. The Food Relative Importance Index was used to assess the relative importance of the prey consumed. Spearman's rank correlation test was applied to compare the diet of S. membranaceus based on climatic seasons, sampling stations and individual size. Analysis of stomach contents revealed that S. membranaceus consumes insects, arachnids, molluscs, macrophytes, phytoplankton, zooplankton and detritus. Fish eggs and scales, nematodes and indeterminate food are also part of his diet. Some stomachs contained grains of sand and mud. These results indicate that this species is benthophageal omnivorous. No changes in diet were observed depending on the seasons, stations and size of the specimens examined. These results indicated dietary flexibility in the S. membranaceus feeding strategy.