Diet comparison in three species of Distichodus Müller & Troschel, 1845 (Distichodontidae, Pisces) of Pool Malebo, Congo River (Democratic Republic of Congo)

Abstract

The diet of Distichodus antonii, D. affinis and D. lusosso was studied in Malebo Pool (Congo River, Kinshasa, D.R. Congo) through the analysis of 396 stomach contents in relation to the size of fish and the hydrological seasons. The Index of preponderance (% Ip) was calculated. The analysis of the preponderance index (Ip) showed that D. antonii and D. affinis are herbivorous. D. antonii feeds mainly on leaves and stems of Echinochloa pyramidalis, while D. affinis consumes in addition roots and detritus. Periphyton was regularly found in the stomach contents of the three species. During the two hydrological seasons, a significant overlap of diet was observed between all the sizes of D. affinis and D. antonii. In D. lusosso, overlap of diet was not observed. Distichdus lusosso is generalist; its food is composed of detritus, animal preys such as fishes, shrimps, crabs, nymphs and larvae of insects, molluscs. This study shows that D. lusosso takes advantage of diversified food items compared with D. antonii and D. affinis. These dietary strategies developed by theses three species contribute probably to their coexistence in Pool Malebo.© 2010 International Formulae Group. All rights reserved.Keywords: Food and feeding, Distichodus species, fish size, competition, D. R. Congo.