An investigation into the food and feeding ecology of a potential aquaculture candidate, Sarotherodon galilaeus multifasciatus in a meteoritic crater lake in Ghana

Abstract

An investigation into the food and feeding ecology of the cichlid, Sarotherodon galilaeus multifasciatus in a tropical meteoritic lake in Ghana was undertaken. Stomachs of the fishes, at two length classes,
representing adults and juveniles, were examined and the food items identified. The juveniles of Sarotherodon galilaeus multifasciatus feed mainly on insect and insect larvae and relatively small quantities of diatoms but avoiding macrophytes. A striking feature in the composition of juvenile diet was the considerable quantities of ingested sand, which constituted about 16% of stomach contents. Ingested sand may be helpful in maceration of food in the pyloric stomach. A sandy substratum may, therefore, appear ecologically important for juveniles of the species. Adult stomachs contained mainly phytoplankton, chironomid and insect larvae with no ingested sand. No significant differences were found in the stomach contents of the fishes for the dry and wet seasons due, partly, to the lack of any considerable seasonal differences in allochthonous inputs into the lake waters. The fishes exploit a wide range of food resources in the open, sub-littoral and littoral zones of the lake. Further studies to include growth and
recruitment are recommended to enhance future production of the species under culture conditions .