PLASMA-CONCENTRATIONS OF TOTAL CHOLESTEROL AND TRIACYLGLYCEROL IN WILD AND CAPTIVE JUVENILE TUATARA (SPHENODON-PUNCTATUS)

Tuatara have been maintained in captivity for over 100 years, but abno rmal growth, high mortality of juveniles, and obesity remain common. A self-maintaining captive colony has yet to be achieved, as the oldest surviving juveniles bred in captivity are only now reaching sexual ma turity. Nutrition may contribute to these problems, as the diets of wi ld and captive tuatara are known to differ. Blood samples were taken f rom wild tuatara on Stephens Island during February, May, August, Nove mber 1992 and January 1993, and from captive tuatara in New Zealand to es during February/March and July/August 1992. The blood plasma was an alysed for concentrations of total cholesterol and triacylglycerol. No significant differences between males and females were found in capti ve or wild juveniles for these lipids. Cholesterol and triacylglycerol concentrations were highly elevated in captive juveniles compared to wild juveniles in both February and August. There was no seasonal vari ation in either of these lipids for the wild juveniles, nor for choles terol concentrations in captive juveniles. However, triacylglycerol le vels of captive juveniles showed significant variation between Februar y and August. Differences in plasma lipid concentrations between wild and captive tuatara may result from differences in diets.