Effects of temperature and salinity on the biological response of mussel (M. galloprovincialis)

In this study the effects of temperature and salinity on some stress indices were evaluated in mussels (M. galloprovincialis) from the Lagoon of Venice (Italy). The aim was to detect and evaluate possible response modulation between organisms from two differently polluted sites. In the first experiment sets, mussels were exposed to water temperatures of 15°C and 25°C, in the second ones to salinity of 26 PSU and 36 PSU. Organisms were sampled after 3 and 6 days and their biological response evaluated at biochemical (aldehyde deidrogenase and catalase activities), cellular (neutral red retention test) and physiological (survival in air) level. The results showed that the applied biomarkers were suitable, as a whole, to make clear the unlike well being of mussels of different origin. Aldehyde deidrogenase activity resulted always insensitive to temperature, and to salinity in the most polluted organisms. Enzyme response was always influenced by different time exposure of both temperature and salinity, except for salinity in less polluted mussels. Catalase activity was always unaffected by salinity, and by temperature in the less polluted mussels. This enzyme activity was influenced by time exposure of both temperature and salinity in the polluted mussels, thus showing the different behaviour of the two populations. Neither temperature nor salinity, nor time of exposure (except for salinity in the less polluted mussels) influenced the results from the neutral red test. Survival in air was always controlled by temperature, salinity, and time of exposure.