DNA damage in Mytella falcata (Mytiloida, Mytilidae) cells: a new tool for biomonitoring studies in tropical estuarine ecosystems.

Resumo

Bivalve filter feeders are sessile animals frequently used as sentinels in aquatic environments. For this reason it is important to identify native key species in tropical environments, since the majority of studies were conducted in temperate regions. This study was developed to evaluate if Mytella falcata, a tropical estuarine bivalve, could be used to detect genotoxic damages by means of the comet assay. Individuals of this species were exposed in vivo to methyl methanesulphonate concentrations; a control group, not exposed, was conducted in the same way. Haemolymph and gill cells were submitted to the comet assay, to evaluate the sensitivity of these tissues. DNA damage increase was detected in both tissues, however statistical difference was observed only in haemolymph cells, maybe because of the damages generated during the dissociation process needed in gill cells manipulation. It was concluded that Mytella falcata had the expected response to this direct acting mutagenic substance and that haemolymph cells are better material for genotoxicity studies, because they can be easily obtained.