Changes in the Diet of Synodontis victoriae and Synodontis afrofischeri in Lake Victoria, Tanzanian waters.

Abstract

The diet of Synodontis victoriae and S.afrofischeri was investigated from samples collected for stomach analysis in May 2013, October 2013, and April 2014 in the Tanzanian waters of Lake Victoria. The diet of S. victoriae was dominated by freshwater shrimps Caridina nilotica followed by unidentified fish remains, the cyprinids Rastrineobola argentea and Enteromius profundus as well as insects, molluscs, haplochromines and worms. The diet of S. afrofischeri was dominated by R. argentea followed by insects, fish remains, worms, molluscs, C. nilotica, algae and haplochromines. There was considerable variation in the diets of both species collected at different times and they displayed considerable plasticity in their diet. Both species exhibited a wider range of diet, utilizing food items that may not have been available before the changes in the lake that followed the Nile perch upsurge in the 1980s.

Keywords: Caridina nilotica, Diet expansion, Food and Feeding habits, Rastrineobola argentea, Seasonal variation