EFFECT OF SALINITY, TEMPERATURE AND ACCLIMATION ON OXYGEN-CONSUMPTIONOF NASSARIUS-FESTIVUS (POWYS, 1835) (GASTROPODA, NASSARIIDAE)

Temperature tolerance (LT(50)) of the scavenging gastropod Nassarius f estivus was determined as 22.5, 64.3 and 160 hr at temperatures of 38, 36 and 33 degrees C, respectively. Hyposalinity tolerance (LT(50)) at salinities of 0, 5 and 10 parts per thousand was found to be 60, 67 a nd 170 hr respectively. Respiration rate was measured at combinations of four levels of temperature (20, 25, 30 and 35 degrees C) and six le vels of salinity (10, 15, 20, 25, 30 and 35 parts per thousand) before and after acclimation. Temperature, salinity and their interactions w ere significant in affecting respiration rate of both non-acclimated a nd acclimated individuals, Among these, salinity has the greatest effe ct. Although respiration rate was increased following acclimation, the values obtained were lower than the control, indicating incomplete ac climation.