Survival and Growth in vitro of Paramoeba perurans Populations Cultured Under Different Salinities and Temperatures

Growth rates of Paramoeba perurans cultures under different temperature and salinity conditions were investigated in vitro over a 15day period. Optimal population growth, under the experimental conditions, was observed at 15°C and a salinity of 35‰, with amoebae populations doubling every 14h. Positive P. perurans populations growth was observed at 15°C between salinities of above 20‰ and 50‰, and at 8°C, 11°C and 18°C at salinities between 25‰ and 50‰, 50‰ being the maximum salinity tested. Amoebae numbers were sustained at 4°C. Therefore, lower temperature and salinity thresholds for P. perurans population growth lie between 4 to 8°C, and salinities of 20 to 25‰, respectively. Upper limits were not determined in this study. The populations remained relatively stable at 4°C and 2°C at permissive salinities with respect to numbers of viable amoebae over the 15day exposure period.