DNA Barcoding for Identification and Discovery of Fish Species in the Protected Mangroves of Hormozgan, Iran

The Persian Gulf is a semi-enclosed marginal sea with a subtropical climate in southern Iran. One of the most productive coastal habitats in this region is the mangrove forests which support rich biodiversity and play an essential role in sustainable fisheries. Because of the fish's dependence on this ecosystem as a nursery habitat and its vulnerability to various natural and anthropogenic stresses and disturbances, it seems critical to identify and classify the fish species in this region and screen biodiversity. A segment (593 bp) of the cytochrome oxidase subunit I (COI) gene was used to identify the fish in the largest mangrove area of the Persian Gulf. In the present study, we created a comprehensive fish barcoding database for 53 species belonging to 39 genera, 32 families, and 17 orders. For six species, novel DNA barcodes to the global gene databases of GenBank and BOLD were introduced (Ilisha megaloptera, Pseudosynanceia melanostigma, Sillago sp., Hyporhamphus sindensis, Johnius sp., Strongylura sp.). Congeneric genetic distances were 46-fold higher than conspecific distances, and a DNA barcoding gap was observed. The tree constructed using maximum likelihood clearly displayed phylogenetic signals at different taxonomic levels. Our results indicated that DNA barcodes served as a valuable tool for studying fish diversity and also for the identification and discovery of fish species in the Persian Gulf. The database developed during this study will contribute to assessing fish biodiversity, conservation, and fisheries management.