Molecular identification of two tilapia species of the genus Oreochromis from Shat Alarab River

In the current study, the two species of Tilapia, including Oreochromis niloticus and O. aureus, collected from Shat Alarab River in the Basrah region, South of Iraq, were identified using the nuclear sox3 gene to confirm their genetic matching. They have been recorded since 2007 in the middle part of Shat Alarab River, Iraq based on morphometric characters; however, there is no evidence to prove how these two species were introduced into the Iraqi inland waters. After collection, morphological characteristics of specimens, including meristic measurement, were counted to identify the two species. Then, their phylogenetic relationship with other available genes from different geographical regions was constructed using maximum likelihood and neighbor-joining algorithms. The results revealed that both species did not belong to a common ancestor. Furthermore, the results confirmed that Scan4ab existed in O. niloticus, but it was not found in O. aureus, showing they are probably not taxonomically related.