Comparison on some biological aspects of Labeobarbus intermedius Rüppell 1835 and Labeo forskalii Rüppell 1836 in Beles and Gilgel Beles rivers, abay basin, Ethiopia

Abstract

Length-weight relationship, Fulton Condition Factor, Sex ratio and fecundity of Labeobarbus intermedius and Labeo forskalii of Beles and Gilgel Beles Rivers were studied. Fishes were sampled using gill nets of various stretched mesh sizes, and hooks and lines. A total of 548 Labeobarbus intermedius and Labeo forskalii fishs were caught in Beles and Gilgel Beles Rivers. Descriptive statistics was used to present the data. One way ANOVA was used to analyze the Fulton condition factor of fishes. The length-weight relationships were curvilinear for L. forskalii and L. intermedius in both rivers. L. forskalii showed isometric growth while L. intermedius exhibited positive allometric growth in Beles and Gilgel Beles Rivers. L. forskalii and L. intermedius were found to be in better condition in both rivers (ANOVA, P 0.05). Females were more numerous than males in the total sexed specimens. Absolute fecundity of L. intermedius increased with an increase in fish size, and ranged from 1535 to 13864 with a mean of 3173 eggs. In general, L. forskalii and L. intermedius were found in better condition in Gilgel Beles and Beles Rivers, respectively. Therefore, sustainable utilization and conservation measures should be taken in the two rivers.