Thirty-five individuals of six priacanthid fish species were sampled from different localities along
the coast of India covering the Arabian Sea and Bay of Bengal. The partial sequence of 16S rRNA
and cytochrome oxidase subunit I (COI) genes were analyzed for species identification and
phylogenetic relationship among the Indian priacanthids (Priacanthus hamrur, P. prolixus,
P. blochii, P. sagittarius, Cookeolus japonicus, and Pristigenys refulgens). The intraspecies genetic
distance ranged from 0.000 to 0.002, while distances varied from 0.008 to 0.157 interspecies
based on 16S sequences. Using COI data analysis, the intraspecies genetic distance ranged from
0.000 to 0.005, while interspecies distances varied from 0.009 to 0.108. Several sequences
labeled Priacanthus hamrur in GenBank are shown to be P. prolixus. We also observed cryptic
speciation in Heteropriacanthus cruentatus. Partial sequences of 16S rRNA and COI genes
provided phylogenetic information to distinguish thirteen species of priacanthids, indicating
the usefulness of molecular markers in species identification
