Sexual dimorphism analysis of rikoo, Glossogobius giuris (Hamilton, 1822) from Mokran basin, Sistan and Baluchestan Province

The sexual dimorphism of Rikoo goby (Glossogobius giuris) were investigated on 60 specimens (30 males and 30 females) sampled from Bahoo-Kalat River in Sistan and Baluchestan Province using electrofishing during summer 2014. The specimens were transported to the ichthyological laboratory of Tehran University. For morphological analysis, 22 morphometric and 5 meristic characters were investigated. The statistical analysis revealed morphological variation among specimens (specially: numbers of the first dorsal fin unbranched rays, numbers of the second dorsal fin branched rays and anal fin branched rays) were more than that of previous reports. The observed results can be a sign of the intraspecific polymorphism. The results of the discriminate function analyzed (DFA) and Permutation test (PT) for morphometric characters and Correspondence Analysis (CA) for meristic characters revealed that there are a wide morphological overlap among sexes and there is no reveal sexual dimorphism among our specimens at least based on our used characters.