Background/Question/Methods Conrad’s false mussel Mytilopsis leucophaeata (Conrad, 1831) is widely invasive bivalves distribution in the south of Iraq. The species is an invasive, brackish water bivalve species originates from the North American Atlantic coast and the northern part of the Gulf of Mexico. The present study is to evaluate the ability of the mussel Mytilopsis leucophaeata to disperse in different habitats with low and high salinity in the south of Iraq. Individuals of the invasive species Mytilopsis leucophaeata were collected from the south of Iraq from April 2020 to February 2021. Specimens were collected using hand picking method. Due to the increasing in the salinity of water streams in the south of Iraq (Shatt Al-Arab River and southern Iraqi marshes), high abundance of this species were recorded. Although, the species can tolerate high salinity to colonise estuarine and coastal areas of Shatt Al-Arab River ranged from 3 to 6 ppt, Mytilopsis leucophaeata could establish in the lower reaches of Tigris River where the salinity reaches 0.4 to 0.6 ppt. This toleration for the low and high salinity give a chance for the invasive species to disperse to different areas in the south of Iraq. Results/Conclusions The deterioration in the water quality of the Iraqi water bodies is due to limited flow from the upper Tigris and Euphrates basin might be a helpful factor for this species and other invasive species in Iraq to colonise and disperse in different habitats.
