Abstract

Information regarding organism changes due to the variation of abiotic factors such as salinity are essential in both ecotoxicological and environmental monitoring studies. For this reason, the Brazilian silverside (Atherinella brasiliensis) embryos were exposed to different salinity conditions (10–35) for 12 days and changes at molecular and individual levels were assessed. The embryos did not present alterations in the morphology or hatching during their development. However, they showed an increase in heart rate after seven days, close to the hatching period. The expression of the cystic fibrosis transmembrane regulator (cftr), one of the channels responsible for osmoregulation, was cloned and it was not significantly affected by the exposure. The obtained results indicated that the Brazilian silverside embryos acclimate in a broad range of salinities and can be used to study fish response at environmentally relevant conditions. In addition, this species can be used to assess the risk related to chemical compounds which toxicity may vary in different salinity conditions.

Keywords:
Salinity tolerance; Silverside; cftr; Embryo test; Heart rate