First application of comet assay in blood cells of Mediterranean loggerhead sea turtle (Caretta caretta)

• There is no record of genotoxicity studies in Caretta caretta.
• A positive correlation between two cells analysis methods was observed.
• No differences were found between animals of different ages.
• Comet is a sensitive test to detect the effects of genotoxins in erythrocytes of C. caretta.

The aim of this study was to validate the comet assay in erythrocytes of Caretta caretta, a species never investigated for genotoxicity. We studied 31 loggerhead sea turtles from three Italian marine rescue centres. Peripheral blood samples were collected from all the animals and the comet assay applied. All comet cells were analysed using two methods: visual scoring and computer image analysis. The % DNA in tail mean value ± SD and Damage Index were 21.56 ± 15.41 and 134.83 ± 94.12, respectively. A strong and statistically significant statistically correlation between the two analytical methods was observed (r = 0.95; p < 0.05). These results demonstrate that the comet assay is a useful method to detect the possible effects of genotoxic agents in loggerhead sea turtle and to increase the knowledge about the ecotoxicological health status of this threatened species.