THE ECOLOGY OF CHONDRUS CRISPUS AT PLYMOUTH, MASSACHUSETTS. III. EFFECT OF ELEVATED TEMPERATURE ON GROWTH AND SURVIVAL

¹ Division of Biological Sciences, Cornell University, Ithaca, New York 14850

Chondrus crispus was cultured under conditions of light intensity, photoperiod, mineral nutrition, and temperature approaching or slightly exceeding those to be expected for a subtidal population at Plymouth. Of these, only temperature beyond a certain point brought reduced growth or mortality. The growth curve breaks sharply between 21.1° and 23.9° C, and morphological abnormalities appear. Cultures do not grow at all at 26.° C. As temperatures are elevated above 21.1° C, healthy spores die in culture in increasing numbers. Healthy spores exhibit mortality approching 100% when exposed to temperatures above 35-40° C, even for periods as brief as one minute, as might be encountered during entrainment in a thermal plume.