Distribution of Oreochromis niloticus (L.) in the Ugandan waters of Lake Victoria

Abstract

The Lake Victoria fish fauna was dominated by cichlids before the establishment of the exotic species Oreochromis niloticus (L.) and Latus niloticus (L.). With the alterations in the ecology of Lake Victoria, changes may be expected to occur in the population dynamics of the fish species. In two zones of Lake Victoria, the size structure, distribution and abundance, condition factors, length-weight relationship and sex ratios of O. niloticus were determined. Larger fish were found in zone II than in zone III, where very few larger fish were recorded. More O. niloticus were caught in zone III, especially in Itome Bay, than in zone II but catch by weight was greater in zone II. More males than females were encountered in both zones. Oreochromis niloticus had similar condition factors in both zones.