Getahun, Abebe (Professor)Mengist, Minwyelet (PhD)Anteneh, Wassie (PhD)Erarto, Felegush2020-11-192023-11-092020-11-192023-11-092020-01-01http://etd.aau.edu.et/handle/123456789/23389Information regarding habitat requirements of different fish species at early life stages plays important roles for monitoring, protecting or managing fish populations and their habitats. Although spawning migration of Labeobarbus species to Gumara River has been reported by various studies, organized information on abundance, distribution, habitat use and preference of young-of-the-year were not available. Such information is very important for the management of the declining endemic Labeobarbus species of Lake Tana. So, the aim of this study was to investigate abundance, habitat use and characterization of young-of-the-year of the Labeobarbus species. Habitat use and characterization of young-of-the-year of the migratory riverine spawning Labeobarbus species of Lake Tana were studied in Gumara River and its tributaries from November 2018 to April 2019. Physico-chemical parameters were measured using probes and there were significant variation (p<0.05) among sampling sites. Fish sampling was conducted using point abundance sampling by electrofishing across banks and mid-channel to cover all habitat types. A total of 3,880 fish specimens were collected from all sampling sites. Out of the total catch, about 24.36% of the contributions were from young-of-the-year of the Labeobarbus species. The abundance of fishes varied between sampling months and sites and this might be attributed to the differences in physico-chemical parameters, substrate type, altitude, depth and velocity of the water. The Shannon’s index (H'=1.21) and evenness value (J'=0.53) in Gumara River indicate moderate pollution and uniform distribution of individuals. Among the six sampling sites, the highest (H' = 1.30) and lowest (H' =0.94) diversity index were recorded at sites in the upstream near to Wanzaye hot spring and below the bridge, respectively. In terms of mesohabitat, the species diversity and evenness were higher in riffle (H' = 1.25, J' = 0.57) than run (H' = 1.15, J' = 0.55) and the pool (H' = 1.11, J' = 0.50). The result showed that the species prefer at a mesohabitat scale riffles and later pools in Gumara River and this is mainly due to the drying of riffle habitats during the dry season and hence forced to shift to pool habitats. At a microhabitat scale also juveniles prefer sites with moderate water depth, low to medium water velocity; gravel substrate type and vegetation cover. Pool habitat served as the only option until the next rainfall comes. Therefore, emphasis should be given to the factors which may lead to the collapse of the pool habitats, especially water abstraction through pumping for small scale irrigation. The detailed study on the habitat modeling and the habitat suitability index should be done for proper management of the Lake Tana fishery.enAbundanceElectrofishingHabitat PreferencesLake TanaYoung-of-the-YearThesis