DNA BARCODING OF HIGH VALUED AQUATIC SPECIES IN COASTAL WATERS OF AURORA PROVINCE, PHILIPPINES

This study was conducted to infer a phylogenetic tree by analyzing the mitochondrial DNA of high-valued species in Aurora Province.

In this study, a total of 121 high-valued species from the coastal waters of Aurora Province were barcoded using the four primer sets of CO1 gene described by Wardet al. (2005), Ivanova et al. (2007) and Folmer et al. (1994). Divergence of sequences within and between species was determined using Kimura 2-parameter distance model, and a neighbor-joining tree was accomplished using 1000 pseudo replications to increase the validity of results.  

A total of 121 cytochrome c oxidase subunit 1 sequences were generated representing 12 orders, 38 families, 62 genera and  89 species of high valued fishes, crustaceans and molluscs collected from the coastal waters of Aurora province. The amplified sequences ranged from 621 to 710 base pairs with an average of 666 base pairs. Mean genetic distances within species, within genus, and within family was 1.69%, 13.3% and 17.9%, respectively. Phylogenetic trees have been successfully constructed using Neighbor-Joining method with Kimura-2 parameter as substitution model. DNA barcoding using the CO1 region has successfully identified the samples down to the species level with 99% success rate. It was also able to reveal possible cryptic speciation in one Cheilinus trilobatus and two Nemipterus japonicas samples with mean intraspecific distance of 2.2% and 9.2%, respectively.

Results showed that CO1 DNA barcodes are effective for rapid and accurate identification of fishes and for identifying species that need further taxonomic evaluation.