Occurrence of Suckermouth Armoured Sailfin Catfishes in Vellayani Fresh Water Lake, Kerala, Southwest Coast of India

The sailfin catfish belonging to the genus Pterygoplichthys of the Loricariidae family has been widely introduced to tropical and subtropical freshwater environments worldwide. It caused serious ecological impacts. Vellayani Lake is the largest fresh water lake in Thiruvananthapuram district, and is the second largest fresh water lake in Kerala. About 42 species of freshwater fishes have been documented from the lake by various authors, primarily from the Department of Aquatic Biology and Fisheries, University of Kerala. A report on the occurrence of exotic South American suckermouth armoured catfish Pterygoplichthys pardalis (Castelnau, 1855), and Pterygoplichthys disjunctivus (Weber, 1991) from this lake is presented in this paper. Morphological study (Weber, 1991 & 1992 and Armbruster et al.2006) was used for the fish identification.