The diet of Oreochromis lidole (Trewavas) and other chambo species in Lakes Malaŵi and Malombe

Oreochromis lidole (Trewavas) is a member of a flock of tilapünes endemic to the Lake Mala% catchment area, of which it is considered to be the most pelagic and planktivorous species. Analysis of the stomach contents of adults from the South East Arm of Lake Malaŵ, from fish caught by both the offshore trawl fishery, and the inshore gillnet fishery, indicates a very narrow dietary breadth, dominated by the filamentous diatom Melosira . The presence of quantities of sand in the stomach indicates that at least some of the food is obtained from sediment feeding. During the breeding season, in November, brooding female O. lidole caught in shallow water exhibited a much broader diet, resembling the more inshore species O. squarnipinnis (Gunther) and O. karongae (Trewavas), with a higher proportion of filamentous chlorophytes and a large amount of sand. Juvenile chambo initially feed mainly on epilithic and epiphytic algae, turning more to plankton and sediment at larger sizes. In general, the different Oreochromiv spp. Caught in the same place at the same time have very similar diets, suggesting that any avoidance of competition for food resources results from habitat partitioning.