Mortality of Mytella falcata and M. guyanensis exposed to different temperatures

Abstract

Mytella falcata and M. guyanensis are species of potential commercial value for aquaculture. The present study had the objective of estimating the mean tolerance (MT₅₀) of both species of estuarine bivalves exposed to different water temperatures. Significant differences were observed through a variance analysis (p = 0.02) between cumulative mortality of both species. M. falcata was more resistant than M. guyanensis at a temperature of 33^oC, with a MT₅₀ of, respectively, 87.42 and 53.36 hours of exposure. Although there was no mortality of the organisms exposed to the other temperatures, control (24°C), 27°C and 30°C, it was found that there is a decrease in the creation of byssus at temperatures of 30°C and 33°C, indicating a possible physiological stress.