Morphological and Environmental Conditions of New Record Earthworm Octolasion cyaneum in Al-Diwaniyah City/Iraq

Background and objective:Octolasion cyaneumis is considered an invasive species. It is endogenous and digs into the upper layers of the soil and rarely appears on the surface. It prefers to live inside the soil, but it reaches the soil level to obtain its food. The aim of this research is to describe the morphological character of earthworm Octolasion cyaneum and to identify the environmental conditions suitable for its living in southern Iraq, specifically in the city of Diwaniyah, Iraq. Materials and Methods: The 70 samples were collected from random locations by excavating and sorting from the location of study in Al-Diwaniyah City in October 2022. The samples were collected by digging the soil to a depth of 20-25 cm with a shovel and placed in plastic containers with a length of 9 cm and a width of 16 cm. Results: Earthworms of the type Octolasion cyaneum(Savginy, 1826) were found near the banks of rivers. It is also found under stones, burrowing tree trunks and near riverbeds 14. The body is cylindrical and the back area becomes octagonal, its length is 65-140 mm and the diameter is 6-8 mm. Conclusion: Some physical and chemical properties of the soil were studied in which this type of worm lives, including temperature, pH, moisture, electrical conductivity, potassium and nitrogen.