PHYLOGENETIC RELATIONSHIPS OF PANGASIIDS (TELEOSTEI: PANGASIIDAE) IN PENINSULAR MALAYSIA BASED ON MITOCHONDRIAL DNA 16S rRNA AND CYTOCHROME OXIDASE I PARTIAL GENE SEQUENCE

The catfishes of the family Pangasiidae are important Asian catfish widely distributed throughout Asia. There are valid 28 species under four genera. However, these groupings are still unstable at the genus level even though many studies have been done to resolve this problem. Only low levels of intraspecific variations were observed. From previous studies, there is no study of the Peninsular Malaysian species' distribution which is located in the middle of the freshwater faunal distribution of South East Asia.

This study presents an analysis on two partial mitochondrial DNA genes (non-protein coding gene partial mtDNA 16S rRNA (16S) and protein-coding Cytochrome c Oxidase I. (COI)) to determine the phylogenetic relationships and genetic variation of the pangasiid catfishes in Peninsular Malaysia.

Samples were collected from Pahang and Perak Rivers using various local fishing gears and traditional methods. Specimens were identified and voucher specimens were preserved. Muscle tissues were taken for molecular analysis where DNA samples were undergo extraction, Polymerase Chain Reaction (PCR) amplification and sequencing processes. Published 16S rRNA and COI sequences were included in the analysis to get better overview of the pangasiid distribution in phylogenetic analyses. Neighbour-joining (NJ), Maximum Parsimony (MP) were run using Tree-Bisection-Regrafting Algoritm (TBR) using MEGA 6.0. Maximum Likelihood (ML) and Bayesian Inference were performed using PAUP version beta 10. Bayesian phylogeny were done using MrBayes version 3.0 implementing Metropolis-Coupled Markov Chain Monte Carlo (MCMCMC) analysis.