Fish Species Composition and Habitat Preferences in the Hadejia River, Jigawa State

The Hadejia River is a significant tributary of the Lake Chad Basin system, supporting important inland fisheries and rural livelihoods in Jigawa State, North West Nigeria. This study investigated the fish species composition, relative abundance, and habitat associations in the Hadejia River at five stations representing different habitats including open channels, marginal vegetation zones, rocky riffles, and pool areas. Sampling was conducted bimonthly over four months using a combination of gill nets, cast nets, and electrofishing. Specimens were identified to species level, counted, and weighed. Habitat variables including water depth, current velocity, substrate type, and macrophyte cover were recorded at each station. A total of 36 fish species from 17 families were documented. Cyprinidae, Cichlidae, and Characidae were the most diverse families. Tilapia zillii was the most abundant species overall. Electrofishing revealed 8 species not captured by conventional nets, particularly in riffle habitats. Species richness was highest in pool habitats with complex structural features. Canonical correspondence analysis identified current velocity and substrate type as the primary drivers of species composition variation between habitats. Marginal vegetation zones supported highest juvenile abundance across multiple species, confirming nursery habitat function. Catches declined progressively toward the most modified sections of the river, which have been subject to gabion construction and channelisation. The study provides habitat-specific fish community data to support ecologically-sensitive river management in Jigawa. Keywords: fish species composition, habitat preference, Hadejia River, freshwater ecology, Jigawa State.