Effect of salinity on bivalve survival Anomalocardia brasiliana (Gmelin, 1791)

Resumo

The objective of this study was to evaluate the effect of salinity on the survival of bivalve mollusc Anomalocardia brasiliana. The experiment consisted of six treatments with the salinities 5, 15, 25, 35, 45 and 55 mg L^-1, with eight replications each. The experiment was conducted with water temperature at 28 ºC and photoperiod of 12 h, with Dissolved Oxygen (DO) at 4.86 mg L^-1 and 60.28% and a pH 7.0. Daily we monitorated these parameters. In each experimental unit, with constant aeration and volume of 3 liters, were placed 18 individuals of A. brasiliana. Three individuals of each experimental unit were removed at times 12, 24, 48, 72, 96 and 240 h after the start of the experiment to verify whether they were alive or dead. All dead individuals removed were discarded, not returning to the experimental unit. Treatments with salinities 5 and 55 mg L^-1 had higher mortality, not presenting any individual living at 240 h. For other treatments 15, 25, 35 and 45 mg L^-1 occurred survival until the end of the study at 240 h. It was found that the treatments of 15, 25, 35 and 45 mg L^-1 showed no significant difference with regard to survival or mortality. It can be concluded that the greater survival occurred in the salinity range 15 to 45 mg L^-1. This allows us to infer that, despite being a euryhaline species, with great tolerance to hyperosmotic media, salinity shock affected the survival and may have caused the death of individuals.