FOOD AND FEEDING-HABITS OF HAPLOCHROMIS (TELEOSTEI, CICHLIDAE) FROM LAKE KIVU IN AFRICA .1. INTERSPECIFIC TROPHIC RELATIONS

The present study deals with the analysis of stomach contents of 456 Haplochromis belonging to 10 distinct species endemic to lake Kivu. It is shown that there is no marked food competition between Haplochromis species. Each species occupies in the lake an ecological niche sufficiently distinct from others and competition for important preys is avoided. The exceptional cases in which competition for food was observed, concern some prey of minor importance suggesting a partial overlap of some Haplochromis species to prey on abundant prey items. It may be concluded that absence of marked food competition among Haplochromis species, is a consequence of adaptative radiation which has resulted in a distinct feeding habit of the different species or the consequence of fixed adaptations probably due to passed competition.