NATURAL DIETS OF SYNODONTIS MEMBRANACEUS FROM IKERE GORGE IN OYO STATE, NIGERIA

Abstract

Natural dietary items in the stomach of Synodontis membranaceus from Ikere Gorge in Oyo State, Nigeria were investigated between the months of October to December 2004 and June to August 2005. Fish species were obtained from fishermen every fortnight using gill net and cast net. Specimens were chilled with iced blocks at the point of collection and transported to the laboratory. 642 fish specimens were examined and their stomach contents analysed. Frequency of occurrence and numerical methods were employed in the study. The result of the analysis showed that the food items found covered a wide spectrum, ranging from various types of planktons to invertebrates and plants. A seasonal variation was also noted in the stomach contents of S. membranaceus over the period of study. The predominant food items found in the stomach were Polycytis spp, Closterium spp, Oedogonium spp., plant tissues, insect parts, paramecium sp., unidentified algae and detritus. This suggests that S. membranaceus is an omnivore.