METABOLISM OF TUATARA, SPHENODON-PUNCTATUS

Rate of oxygen consumption was used as an index of metabolic rate in r esting male, female and juvenile tuatara of a large range of sizes (6. 8-746 g) on Stephens Island, New Zealand. Metabolic rate was measured within 72 hours of capture at 10-15 degrees C. Metabolic rates were ad justed to 13 degrees C and varied with mass with a metabolic scaling e xponent of 0.62. Metabolic rates of juveniles were higher than expecte d at 13 degrees C for lizards of similar mass, but rates for adult tua tara were approximately the same as expected for lizards at 13 degrees C. Body temperatures of 142 active tuatara were measured during the d ay and night and ranged from 5.2-11.2 degrees C. Hence, standard metab olic rates of tuatara close to their activity temperatures (at 13 degr ees C) are low compared to standard rates for lizards at their active temperatures that are normally in excess of 20 degrees C. (C) 1998 Els evier Science Inc.