An Investigation on Genotoxic Effects of Arsenic on Caspian Roach (Rutilus Caspicus) Using Micronucleus and Comet Assays

Arsenic, as a pollutant, can lead to serious problems in aquatic organisms and human. In the present study, considering the economic and ecological value of Caspian roach, Rutilus caspicus, genotoxic effects of arsenic on this species were assessed using the comet and micronucleus assays in 2016.

At first, the fish were exposed to the concentrations of 3, 6 and 9 mg L-1 arsenic. A control treatment without arsenic was also considered. Sampling was done during the 3 and 7th exposure days. To perform micronucleus test, blood sampling was done at two times and micronuclei frequency was determined. To perform comet assay, sampling was done from the fish gill tissue and the DNA damage parameters were assessed.  

Exposure to the arsenic led to the induction of micronuclei formation in the erythrocytes and DNA damage in the gill tissue. So that micronuclei frequency and values of damage parameters in the treatments exposed to arsenic significantly increased compared to the control (P≤0.05). The induced damage level was dependent on the exposure time and concentration. The highest levels of damage parameters including Tail Length, Tail Moment, %Tail DNA and also micronuclei frequency were 101.1±1.55, 57.11±1.64, 59.45±3.09 and 2.26±0.58, respectively which observed in the treatment exposed to 9 mg L-1 arsenic.

The results from the present study indicated sub-lethal concentrations of arsenic can cause micronuclei formation and induction of DNA damage in Caspian roach. Therefore, it could be stated that arsenic has genotoxic effects on Caspian roach.