Osteology of the Caspian bighead goby, Ponticola gorlap (Iljin, 1949) (Teleost: Gobiidae) from the southern Caspian Sea basin

The Caspian bighead goby(Ponticola gorlap), a member of the family Gobiidae, is found on the southern Caspian Sea basin. Since little information is available about the skeletal structure of this species, therefore, this study was conducted to describe its detailed skeletal structure in the southern Caspian Sea. For this purpose, a total of 17 specimens were collected from Sefid River by electrofishing device. After anesthesia, they were fixed into 10% buffered formalin, and for osteological examination, they were cleared and stained and, their bony characteristics were described in detail. The results showed that Iranian populations of this species can be identified by having traits, including sharp point of the lateral ethomoid, lack of the nasal, separation of the horizontal part from the vertical part of the premaxilary, presence of an ascending process in the dentary and separation of the symplectis and metapterygoid.