Molecular identification of three invasive suckermouth catfish (Pterygoplichthys spp.) from the Buriganga River, Bangladesh

Abstract

Invasive suckermouth catfishes (Pterygoplichthys spp.) are widespread in Bangladesh but their species composition is poorly characterized due to previous records relying on morphological identification. The present study aimed to determine the taxonomic status of Pterygoplichthys populations of the Buriganga River, Bangladesh, by employing DNA barcoding of the mitochondrial cytochrome c oxidase subunit I (COI) gene. Fourteen specimens were collected from three sampling sites and were first identified by their morphological features. Genomic DNA was isolated from muscle tissue and a 655 bp fragment of the COI gene was amplified and sequenced. The sequences were compared to reference sequences in the NCBI GenBank and Barcode of Life Data System (BOLD) databases. Molecular analysis revealed the presence of three species of Pterygoplichthys in the Buriganga River namely, Pterygoplichthys disjunctivus, P. ambrosettii and P. pardalis. Sequence comparisons showed high query coverage (≥99%) and sequence identity (99–100%) with authenticated reference sequences, supporting accurate species-level identification. Phylogenetic analysis grouped the specimens into three distinct clades corresponding to the identified species and revealed close genetic relationships with populations from both native and introduced regions worldwide. These findings demonstrate that the sampled specimens revealed the presence of at least three Pterygoplichthys species. This study provides the first molecular evidence for the coexistence of P. disjunctivus, P. ambrosettii, and P. pardalis in Bangladesh. The results provide important baseline information for developing management strategies to evaluate the impacts of invasive species. Dhaka Univ. J. Biol. Sci. 35(2), 1-18, 2026 (July)