FOOD AND FEEDING HABITS OF THE CATFISH, BAGRUS DOCMAK (FORSSKAL, 1775) (PISCES:BAGRIDAE) IN LAKE CHAMO, ETHIOPIA

Abstract

The natural food of the catfish Bagrus docmak was studied
from February -1995 to February 1996 in Lake Chama, Ethiopia. The
stomach contents. of a total of 534 fish samples, ranging in size £rom 33-99 cm fork length (LF) and 500-17400 g in tOtal weight (WT) were
investigated. The diet of B. docmak was composed of ins~ (larvae,
nymphs and adults), aquatic snails and different fish species such as
Synodontis schall, Labeo horie, Oreochromis. niloticus, Barbus sp. and
Hydrocynus forskalii. Juvenile B. docmak « 40 em LF) ingested more insects than fish while older fish were largely piscivorous, with fish constituting more than 98% of their diet by weight. S. schall was the most important prey and occurred in more than 81 % of all the stomachs of large B. docmak. The prey:predator (S. schall:B. docmak) length ratio varied between 1:2 and 1:6. The feeding habit of B. docmak in Lake Chama is compared with that of other tropical African lakes that have similar ichthyofauna.