Fish Assemblages And Stream Habitat Types In South Indian Streams

Abstract

Based on the habitat types, thirty species of cyprinids in nine streams located in the Western Ghat mountain ranges, hotspot of biodiversity have been classified into six guilds. Shallow pools (<60cm deep and velocities <30 cm/s) were preferred by juveniles and adults of big sized barbs such as Hypselobarbus micropogon, Tor khudree and Neolissochilus wynaadensis. Slow riffles (< 60 cm deep and velocities 30-59 cm/s) were preferred by juveniles of surface dwellers such as Barilius canarensis, B. gatensis, Devario aequipinnatus, Salmophasia boopis, Salmophasia acinaces and Chela labuca; bottom and substrate dwellers such as Garramullya and Garra stenorhynchus. Fast riffles (< 60 cm deep and velocities ≥ 60 cm/s) were preferred by the surface dwelling species and species of Garra. Almost all the cyprinid species preferred the medium pool (60-149 cm deep and velocities <30 cm/s). Big sized barbs and torines (game fish) were confined to deep pools (≥150 cm deep). Among the nine streams raceway is identified in one stream (60-149cm deep and velocities ≥30 cm/s) which was preferred by juveniles and adults of Garra stenorhynchus and Barilius gatensis. Guild structures of cyprinid species are consistent in almost all the streams.