Evaluation of DNA Damage of Cadmium in Gastropod Lymnaea radix cor (Annandale and Prashad, 1919) From Euphrates River

Cadmium toxicity to a snail Lymnaea radix cor collected from Shatt Almadina stream that belongs to Euphrates River, Basra province, Iraq was investigated. DNA damage was used as an indicator for cadmium toxicity in the current study. The adult snails were exposed to several concentrations of cadmium for different periods. DNA fragmentation occurring in the snail exposed to cadmium was substantiated by comet assay and expressed in term Tail DNA percentage. Results revealed a significant increase in DNA damage at cadmium concentrations 60, 80, and 100µg/l for an exposure time of 3 days, and the highest percentage of tail DNA was at the cadmium concentration of 100µg/l. On the other hand, the DNA damage significantly elevated when the exposure period increased to 5 days and the highest tail DNA percentage (18%) was recorded at cadmium concentration 100 µg/l. the assessment of DNA damage in the freshwater snail Lymnaea radix cor gives an early caution signal for aquatic environmental contamination by cadmium.