Observations on the breeding biology of <i>Sarotherodon macrochir</i> (Boulenger) in Lake Mcllwaine, Rhodesia

Sarotherodon macrochir matures at 17–18 cm standard length in Lake Mcllwaine and males grow larger than females. There is an extensive breeding season with the main breeding taking place during September‐February, the hottest period of the year, which is just before the rainy season. Female S. macrochir produce about 1000 to 5000 eggs in their ovaries and can brood up to 800 eggs in their mouths. Mean brooding efficiency is about 75 % but this declines as the fish increase in size.