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

Abstract

194 specimens of Scartelaos tenuis (Day 1876) collected from five stations in the northern Persian Gulf, Strait of Hormuz (Qeshm Island), and the Gulf of Makran were compared by means of geometric morphometrics, using 14 morphological landmarks. The two sexes did not show significant difference in shape. Fish samples are classified into two distinct groups, the sample from the northern Persian Gulf (Heleh and Asaluyeh), and the rest of the specimens (Chahoo, Dargahan and Jask). The Persian Gulf and the Gulf of Makran are characterised by different environmental parameters of surface waters, including temperature and salinity. The shape of Scartelaos tenuis specimens of different stations with different temperature and salinity readings statistically differ (ANOVA analysis). Correlation tests prove that temperature and salinity are two factors that affecting the shape of S. tenuis populations in the Persian Gulf and Makran Sea. Our results suggest that the observed pattern of morphological variation is almost a phenotypically plastic response to different environmental factors.