The Trophic Structure and Diversity of Haplochromines among the Kyoga Minor Lakes

Abstract

Before the introduction and establishment of the Nile perch, Lates nilolicus (L). Lakes Victoria and Kyoga had a diverse fish fauna, dominated by haplochromine cichlids. The haplochromines had evolved into many trophic groups which occupied virtually all trophic levels and contributed to the ecological efficiency of the lakes. Establishment of Nile perch in the main lakes was followed by a decline and in some cases complete disappearance of many haplochromine trophic groups. This is thought to have affected the efficiency of the ecosystem. This study examined the species composition and trophic diversity among haplochromines in Kyoga Minor lakes where Nile perch was not introduced and compared this with historical data from Lake Victoria. Six Kyoga Minor lakes and the main Lake Kyoga (Iyingo) were sampled. Forty one haplochromine species were recorded in the Kyoga lake basin and only fourteen species were recorded from the main Lake Kyoga. Species and trophic diversity of haplochromines were highest in the Kyoga Minor lakes as compared to Lake Kyoga