The feeding habits of Alestes baremose and Hydrocynus forskali (Pisces) in Lake Albert, East Africa

Abstract

The stomach contents of 1922 Alestes baremose Joannis and 1184 Hydrocynus forskali Cuvier caught in Lake Albert, East Africa were examined. The fish were caught in gill nets in three main different types of habitat; in lagoons, inshore in the main body of the lake and offshore. Zooplankton, ephemeropteran imagines and higher plant species constituted almost the whole diet of A, baremose, although the relative importance of these three items varied with habitat. In the lagoons and inshore Hydrocynus forskali was mainly piscivorous, but offshore where the largest specimens occur it was feeding mainly on Caridina nilotica. The role of Hydrocynus species as predators in Lake Albert is discussed and it is shown that in this lake predation intensity bythis genus must be considered entirely in terms of H.forskali.