Traditionally fish from family Sillaginidae considered as Sillago sihama in the North Persian Gulf. Genetic as well as
morphological analyses were used to study species differentiation of Sillaginids in the North Persian Gulf. Meristic counts
and geometric morphometrics were used to morphologically differentiate specimens. We sequenced a 620 bp fragment from
the mitochondrial cytochrome c oxidase subunit I gene (COI) of Sillaginids collected from the north Persian Gulf and
analysed in contrast to sequences from the GenBank. In spite of inconspicuous meristic features, no significant
morphometric differences between samples was observed, however based on analysed sequences and phylogenetic
relationships of the samples three species of Sillaginids were revealed. Except for Sillago sihama, no previous barcodes
were available for other two species Sillago arabica and Sillago attenuata in the GenBank. The results of the present study
revealed that at least three species of Sillaginids apparently identical are present in the North Persian Gulf, Therefore,
precautionary consideration by environmental and fisheries managers is recommended.