DNA barcoding for identification of ichthyofauna in Pantabangan Dam, Nueva Ecija, Philippines

The present study established the first molecular-based inventory of nine freshwater fish species from Pantabangan Dam, a genetically unexplored fishery resource in Nueva Ecija, Central Luzon region of the Philippines. Forty mitochondrial cytochrome c oxidase I (COI) sequences were generated representing nine species, eight families and six orders of fishes, providing potential application in biodiversity assesment and management. In all cases, sequence analysis yielded low intraspecific divergence and a high interspecific genetic distance was observed in the Nearest Neighbor Distance analysis. Neighbor-Joining and Maximum Likelihood phylogenetic trees recovered a monophyletic species-level clades supported by high bootstrap values. Out of the nine species identified, three were native species in the Philippines (Leiopotherapon plumbeus, Glossogobius aureus and Clarias batrachus). Two species (Micropterus floridanus and Coptodon zillii) have been recorded for the first time in the dam, indicating the need to review how monitoring protocols can be enhanced by combining morphological assessment and molecular identification. The generated sequences can be used as a baseline data for the conservation of endemic species and formulation of management decisions on the invasive fishes. Overall, our study confirmed the efficiency of DNA barcoding in species delineation and offered a new framework for fish management in the dam.