DNA barcoding delineates the identity of invasive South American sucker mouth armoured catfishes of genus Pterygoplichthys of East Kolkata Wetland, West Bengal, India as single species

Abstract

Invasive suckermouth armoured sailfin catfishes of Pterygoplichthys genus is a threat to natural fish biodiversity. We
attempted to identify suckermouth armoured sailfin catfishes, Pterygoplichthys spp. which have successfully invaded
and established in the East Kolkata Wetland, using morphological and molecular techniques. Based on the colouration
pattern/spot on the belly region they were categorised into three groups viz., Pterygoplichthys pardalis, Pterygoplichthys
disjunctivus and an intermediate group. In total, fin clips from 32 individuals were collected from the above three groups
and a portion of mitochondrial cytochrome oxidase subunit-I (COI) gene was sequenced using Sanger’s method. Out of the
32 individuals, good quality sequences were obtained for 30 individuals. Surprisingly, mtDNA COI gene sequence analysis
revealed that a sequence length of 581 bp was identical among all individuals. Species level barcode records from BOLD
database revealed the identity of specimens in all categories as P. pardalis. Results of the study suggest that Pterygoplichthys
established in East Kolkata Wetland might have originated from a single reproducing entity.

Keywords: Cytochrome oxidase subunit1, East Kolkata Wetland, Mitochondrial DNA, Pterygoplichthys, Suckermouth
sailfin catfish