RESUMO
We evaluated whether life-time exposure to PFOS affects egg development, hatching, larval development, survival, metamorphosis and body mass of Enallagma cyathigerum (Insecta: Odonata). Eggs and larvae were exposed to five concentrations ranging from 0 to 10000 microg/L. Our results show reduced egg hatching success, slower larval development, greater larval mortality, and decreased metamorphosis success with increasing PFOS concentration. PFOS had no effect on egg developmental time and hatching or on mass of adults. Eggs were the least sensitive stage (NOEC=10000 microg/L). Larval NOEC values were 1000 times smaller (10 microg/L). Successful metamorphosis was the most sensitive response trait studied (NOEC<10 microg/L). The NOEC value suggests that E. cyathigerum is amongst the most sensitive freshwater organisms tested. NOEC for metamorphosis is less than 10-times greater than the ordinary reported environmental concentrations in freshwater, but is more than 200-times smaller than the greatest concentrations measured after accidental releases.
Assuntos
Ácidos Alcanossulfônicos/toxicidade , Monitoramento Ambiental , Fluorocarbonos/toxicidade , Insetos/efeitos dos fármacos , Estágios do Ciclo de Vida/efeitos dos fármacos , Poluentes Químicos da Água/toxicidade , Animais , Feminino , Insetos/crescimento & desenvolvimento , Insetos/fisiologia , Larva/efeitos dos fármacos , Larva/crescimento & desenvolvimento , Larva/fisiologia , Masculino , Oviposição/efeitos dos fármacosRESUMO
Perfluorooctane sulfonic acid (PFOS) is a persistent and ubiquitous environmental contaminant that has been detected in organisms worldwide. Here, we evaluate whether long-term (1 and 4 months) exposure to PFOS contamination affects the behavioural performance of freshwater larvae of the damselfly Enallagma cyathigerum (Insecta: Odonata). Our results show reduced behavioural performance with increasing PFOS concentration. In 1 month exposed larvae, no observed effect concentrations (NOECs) were 100 microg/L for general activity. In 4 months exposed larvae, NOECs were 10 microg/L, for each behavioural trait, except swimming acceleration of male larvae where the NOEC was 100 microg/L. When faced with PFOS concentrations above the NOEC, E. cyathigerum larvae were less active, less capable to escape a simulated predator attack and less efficient in foraging. Together, our results show that damselfly larvae suffer reduced survival-related behavioural performance.