Filter-feeding habit of the African catfish Burchell, 1822 (Pisces: Clariidae) in Lake Chamo, Ethiopia

The feeding habit of the African catfish Clarias gariepinus (Burchell) was studied by assessing the stomach contents of 419 fish (287 juveniles - 17.1-44.7 cm TL and 132 adults - 55.2-109.0 cm TL) collected between February 2003 and January 2004 in Lake Chamo.  Different kinds of food items were found in the stomachs such as zooplankton, insects, fish scales, fish and detritus. Zooplankton occurred in 75.4% of the stomachs and accounted for 83.1% of the total volume of food consumed. Detritus occurred in 33.7% of the stomachs and contributed 10.9% of the total volume of food items. Fish ( O . niloticus ) occurred in 15.5% of the stomachs and accounted for 4.2% of the total volume of the food organisms. Fish scales were found in 20.5% of the stomachs and contributed 1.2% of the total volume of food items. Insects occurred in 27.2% of the stomachs but their volumetric contribution was relatively low accounting for only 0.6% of the total volume. Generally juvenile fish tended to feed on relatively higher proportion of insects and detritus while adults tended to feed more on zooplankton. Keywords/phrases : Clarias gariepinus , Filter-feeding, Lake Chamo Ethiop. J. Biol. Sci ., 8(1): 15-30, 2009