Reproductive dynamics, food and feeding habits of the African big barb ( Labeobarbus intermedius ) (Rüppell, 1835) (Pisces: Cyprinidae) in Lake Tinishu Abaya, Ethiopia

The reproductive biology and feeding habits of Labeobarbus intermedius (Rüppell, 1835) in Lake Tinishu Abaya were investigated from February 2023 to January 2024 using 365 specimens collected by gillnets. The overall sex ratio was skewed toward males (1:0.65, M:F) and differed significantly from the expected 1:1 ratio. The length at first maturity (Lm50) was 22.1 cm fork length (FL) for males and 22.7 cm FL for females. Mean fecundity was 765 ± 120 eggs per female, with peak spawning occurring during June, July and November, although reproduction occurred throughout the year. Diet analysis showed that insects, phytoplankton, macrophytes, and detritus were the principal food items. Seasonal variation in diet was evident, with insects and phytoplankton dominating during the dry season, while macrophytes and detritus were more important during the wet season. An ontogenetic dietary shift was also observed, with juveniles consuming more insects and zooplankton and adults feeding mainly on macrophytes and detritus. These findings suggest that protecting fish smaller than 22.7 cm FL and restricting fishing during peak spawning periods would support sustainable management of the fishery.