GEOGRAPHICAL COLOR VARIATION IN CICHLID FISHES AT THE SOUTHERN END OFLAKE TANGANYIKA

Geographical colour variation and distribution of 48 common cichlid fi sh species were studied at 20 sites along an 85 km shoreline at the so uthern end of Lake Tanganyika, Africa. Sixteen species had two or more colour morphs and 11 species showed a limited distribution in the stu dy area. They were all rock-dwellers. Distributional borders of the co lor morphs and species with a limited distribution mostly lay in two l ong sandy beaches, 7 and 13 km long. We suggest that the long sandy be aches can be effective barriers against dispersal of shallow-water roc k-dwelling cichlid fishes.