Shape variation of the Indian Ocean slender mudskipper, Scartelaos tenuis (Day, 1876) from the Persian Gulf and Oman Sea (Gobioidei: Gobiidae)

The shape diversity among populations of Scartelaos tenuis (Day 1876) from five stations (194 specimens) in the Persian Gulf, Strait of Hormuz (Qeshm Island), and the Sea of Oman were investigated. The shape variation was assessed by geometric morphometrics, using 14 morphological landmarks. The two sexes were not distinguishable by the shape. Fish samples were classified into two distinct groups, the fish from the Persian Gulf (Heleh and Asaluyeh), and the specimens of Qeshm Island and the Sea of Oman (Chahoo, Dargahan and Jask). The Persian Gulf and the Sea of Oman are characterized by specific environmental parameters of surface waters, including temperature and salinity. The shape discrepancies of Scartelaos tenuis specimens from different stations are probably because of ecological parameters of the Persian Gulf and Sea of Oman. Our results suggest that the observed pattern of morphological variation is almost some kind of polyphenism induced by distinct environmental factors.