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

Fabrea salina, a marine ciliate belonging to the order Heterotrichida, shows positive phototaxis and photophobic step-down reactions. In thi s work, we have investigated the effect of temperature on the motion p arameters and the phototactic reaction. In the temperature range inves tigated, there is a quasi-linear increase in speed with temperature. I n addition, the positive phototactic reaction is enhanced by an increa se in temperature. These results are discussed on the basis of possibl e physical and physiological mechanisms.