Comparison study of morphological variations among populations of Blennies, Omobranchus genus, in the Iranian Coasts of the Persian Gulf and the Gulf of Oman using Geometric Morphometrics Method

The objective of this study was to determine the body shape variations among the Blenny populations, Omobranchus genus in the Iranian Coasts of the Persian Gulf and the Gulf of Oman, using landmark-based geometric morphometrics. Therefore, a total of 120 specimens of Omobranchus genus including the species of Omobranchus fasciolatus (80 specimens from Hengam, Hormuz and Daryabozorg stations), Omobranchus punctatus (10 specimens from Bandar Ameri station) and Omobranchus mekranensis (30 specimens from Daryabozorg Station) collected from the rocks and coastal pools of Bandar Ameri, Hengam and Hormuz stations in the Persian Gulf and Daryabozorg station in the Gulf of Oman in the winter. In order to study and compare the morphological features of different populations of Blennies, the left side of the specimens was photographed and 14 landmark-points were digitized on two-dimensional images using TpsDig2. Landmark data were analyzed after a generalised procrustes analysis using PCA, CVA and cluster analysis and the patterns of body shape differences among the populations were illustrated in the deformation grids in relation to consensus configuration. The results showed a significant difference among the five studied populations in terms of morphological traits (P< 0/0001) and the most important traits expressing intergroup changes based on loading diagram were including landmarks of the notch between two dorsal fins, beginning and end points of the anal fin in the first principal component (PC1) and the initial point of anal fin, notch of two dorsal fins and the lower point of the gill opercula in the second principal component (PC2). The results of this study can help to better understand patterns of morphological variability of these fish in the waters of the southern Coast of Iran.