DNA barcoding of commercially important Grouper species (Perciformes, Serranidae) in the Philippines

Fish identification is generally challenging because of their unpronounced and overlapping morphological characters which is true in grouper species. In the Philippines, an updated, reliable and accurate inventory of this high value commercial groupers has not been carried out previously. Using molecular tools in the identification and inventory of fish species in the country is confined to few laboratories and experts in the country. In this study, 27 species of the Serranidae family were identified from the grouper samples collected from major fish landing sites and markets in the Philippines. The grouper species were molecularly identified using the cytochrome c oxidase I (COI) sequences for DNA barcoding. The accuracy of the inferred species-level taxonomy based on COI is supported with high similarity search (98-100%) both in BOLD and BLAST, well-distributed genetic distance values and cohesive clustering in the Neighbor-Joining Tree. Aside from reinforcing the classical methodology of grouper identification in the country, this pioneering study on molecular identification of Philippine groupers constitutes a significant contribution to the DNA barcode library of Philippine marine fishes and to the global barcode entries in general, which can be used when dealing with grouper taxonomy, biodiversity, stock assessment and trade. The results reveal the different localities where the grouper species can be possibly sourced out in the country for trade and aquaculture purposes. Several of the grouper species are included in the IUCN Red List of Threatened Species. As a tool for conservation ecology, this study signals the implementation of sustainable fisheries management regulation to protect in particular those which are listed under the IUCN.