DNA BARCODING OF ENDANGERED GIANT CLAMS IN ISLANDS OFF THE EAST COAST OF PENINSULAR MALAYSIA

This study reports on the taxonomic verification and distribution of three presumed morphologically identical Tridacna species (giant clams), namely T. crocea, T. maxima and T. squamosa, from nine localities in islands off Terengganu, Pahang and Johor in the east coast of Peninsular Malaysia.A 467-bp partial sequence of mitochondrial DNA cytochrome c oxidase 1 (MT-CO1), which serves as the DNA barcoding gene, was analysed for species identification of 247 samples.The MT-CO1 gene was successfully used to identify all the giant clam samples to species level based on GenBank BLAST and BOLD databases.Three highly-supported clusters were obtained, which supported the morphological species determination into T. crocea, T. maxima and T. squamosa.However, a few discrepancies were observed, which could be attributed to misidentification of juveniles.T. squamosa and T. crocea were more closely related to each other compared to T. maxima.T. maxima and T. squamosa were found to be ubiquitous in all the islands, while T. crocea was restricted to the southeastern islands of Pahang and Johor.The precise identification of samples through the MT-CO1 gene and information on their distributions are useful in strategising the conservation and management of giant clams in this region.