Diversity of fishes in Beles and Gilgel beles Rivers, abay basin, Ethiopia

Abstract

Diversity of fish species of Beles and Gilgel Beles Rivers were studied. Fishes were sampled using gill nets of various stretched mesh sizes, and hooks and lines. Identification of fish was made to species level by comparing the sample characters with taxonomic keys found in literatures and specimens deposited. Shannon diversity index (H`) was used to evaluate species diversity of fishes. A total of 1124 individual fishes belonging to 5 orders, 7 families, 13 genera and 23 species were caught in Beles and Gilgel Beles Rivers. Cyprinidae was best-represented family with the highest number of fish species in the rivers while Labeo and Labeobarbus were the best-represented genera. A higher number of species were recorded in the Beles River (22 species) than in the Gilgel Beles River (5 species). The diversity index was higher in the Beles River (H´=2.43) than in the Gilgel Beles River (H´ = 0.88). In general, Beles River is richer than Gilgel Beles River, in terms of total numbers of fish caught and number of species recorded. In order to have a better knowledge of the fish populations in the study area, further studies are required on diversity, abundance and biology of the fishes. Therefore, sustainable utilization and conservation measures should be taken in the two rivers.