INCREASE IN RANGE OF TEMPERATURE TOLERANCE BY ACCLIMATION IN THE COPEPOD EURYTEMORA AFFINIS

¹ Department of Biological Sciences, University of Maryland Baltimore County, Catonsville, Maryland 21228

The copepod, Eurytemora affinis, was tested for its ability to recover from short exposures to a high temperature (temperature tolerance). Animals kept at a warm temperature for several hours or days before the test increasd in tolerance (acclimation). Females showed higher tolerance and acclimation than males. Temperature tolerance was greater at a higher salinity (13 vs. 0), but acclimation was not. Analogous tests were done at low temperatures. Acclimation to cold temperature also occurred, but more slowly. Sexual differences were less marked than for heat tolerance. When tested on the same animals, heat and cold tolerances seemed to be positively related traits.