Studies on the physiological variation between tropical and temperate zone fiddler crabs of the genus Uca—V. Effect of temperature on tissue respiration

Abstract

1. 1. The metabolic-temperature curves for the supraoesophageal ganglion (SEG), the heart and muscle tissue from three species of fiddler crabs have been determined. Two of the species, Uca pugilator and U. pugnax are temperate zone species. U. rapax is a tropical zone organism. 2. 2. The tissues from both cold- and warm-acclimated U. pugnax tendend to have a higher metabolic rate than those from cold- and warm-acclimated U. pugilator and U. rapax. 3. 3. The metabolic temperature curves are different for the tissues of each species of crabs. 4. 4. The SEG of all three species showed reverse adaptation to thermal acclimation. The Q 10 values of the SEG were high at the approximate same temperature ranges as has been reported for whole animals. There is no correlation between the Q 10 curves for the other two tissues and the Q 10 curves for the whole animals. 5. 5. At low temperature the Q 10 values for the SEG shifted with acclimation in U. rapax but not in the temperature zone forms. 6. 6. At low temperatures the Q 10 values of the muscle tissue of the two temperate zone crabs shifted with acclimation. This tendecy was not observed in the tropical zone species. 7. 7. Data were analyzed and compared, using the classifications proposed by Precht and Prosser.