Morphological comparison of Urohyal and Otolith in taxonomic identification of two species of mullets (Mugilidae: Teleostei) in Persian Gulf

Mullets have fisheries values. These fishes show high interspecific similarities, and this often made them difficult to identify. Therefore, finding the morphological characters for their identification is very important.In this study, taxonomic significance of the hard structures such as Urohyal bone and sagittal otolith were examined. To do this objective, a total of 56 mullet specimens belong to Chelon subviridis and Chelon klunzingeri were collected from Bandar-e-Lengeh, Bandarabbas and Qeshm, and fixed in 75 % ethanol. In laboratory, urohyal bones and sagittal were extracted following the standard method, and their morphology described and interspecific variations were studied. The results showed that both morphology and morphometry of these hard structures can be especially useful in discrimination of the mullets. However, it seems that urohyal bone has particular importance in species separation. Therefore, in addition to the genetic studies, studying of the urohyal bone can play important role in understanding of taxonomic and phylogenetic relationships of the fishes.