Effect of temperature acclimation on the metabolic rate of sea urchins

Three sea-urchin species were acclimated at 9° and 18°C for 30 days. Following acclimation, oxygen-consumption measurements were made over a broad temperature range (6° to 24°C). The effect of temperature acclimation on the metabolic rate-temperature relationship (R-T curve) was determined for each species. R-T curves of Strongylocentrotus purpuratus generally indicate no compensation (Precht type 4). Some inverse compensation (Precht type 5) is suggested at intermediate test temperatures. R-T curves of Strongylocentrotus franciscanus indicate inverse compensation particularly at intermediate test temperatures. R-T curves of Allocentrotus fragilis generally indicate no compensation. With two species, S. purpuratus and A. fragilis, greater levels of rate-temperature independence were generally reached by cold-acclimated forms at lower test temperatures and by warm-acclimated forms at higher. Rotational (slope) changes in these R-T curves may be more critical than translational (ordinate) changes.Supported in part by a National Science Foundation Institutional Sea Grant to Oregon State University.Submitted in partial fulfillment of the requirements for the degree of Master of Science, Oregon State University, June, 1970.