TEMPERATURE EFFECTS ON MOTION PARAMETERS AND THE PHOTOTACTIC REACTION OF THE MARINE CILIATE FABREA-SALINA

Fabrea salina, a marine ciliate belonging to the order Heterotrichida, shows positive phototaxis and photophobic step-down reactions. In this work, we have investigated the effect of temperature on the motion parameters and the phototactic reaction. In the temperature range investigated, there is a quasi-linear increase in speed with temperature. In addition, the positive phototactic reaction is enhanced by an increase in temperature. These results are discussed on the basis of possible physical and physiological mechanisms.