DNA Barcoding and Phylogenetics Relationship of Pangasiid Catfishes in Peninsular Malaysia Revealed the Impacts of Aquaculture on the Native Species Conservation

Pangasiids are an economically significant group of catfish, and many pangasiids threatened in the wild from anthropogenic pressures, including increases fishing pressure, habitat degradation, improperly managed aquaculture practices. This study demonstrates usage DNA barcoding Cytochrome Oxidase subunit I (COI) gene as identification tool detecting potentially threatening invasive pangasiid species by establishing diversity phylogenetic relationship Pangasiidae catfishes Peninsular Malaysia. A neighbour-joining (NJ) dendrogram (Kimura-2-parameter model) generated five clades to represent distinct genera. Pangasius was further subdivided into two (Clade A: bocourti-P. djambal Clade B: P. nasutus-P. conchophilus). Given marginal genetic divergence, indigenous non-native should be treated cautiously allopatrically distributed species. The analysis used Automatic Barcode Gap Discovery (ABGD) revealed barcode gaps between intraspecific interspecific distances. sequences were partitioned groupings, corresponding with delineation based on distribution pairwise differences, which could not differentiated using NJ dendrogram. ABGD allows recognition one or additional recursive approach, but other taxonomic methods considered for a solid conclusion. closely related species, thus justifying its application towards conservation these fish.