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 lakes 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.