Occurrence of a Pterygoplichthys disjunctivus (Weber, 1991) population in Cauvery River System, Tamil Nadu, South India

This study reports the first occurrence of exotic loricariid catfish Pterygoplichthys disjunctivus, introduced for aquarium, in tributaries and fed pond of Cauvery River, Thiruvengadu, Tamil Nadu (South India). The morphological features of P. disjunctivus samples are given and compared with closely related species of the same genus. The observed invasive species is highly aggressive in nature and it was reported to represent about 80% of the total fish community of the study area, reflected the depletion of fish. The impacts of this species on the biodiversity of native fishes in inland water body are also reported. Key words: Loricariid catfish, Cauvery basin, native species, alien fish species.