Plasma concentrations of total cholesterol and triacylglycerol in wild and captive juvenile tuatara (Sphenodon punctatus)

Abstract

Tuatara have been maintained in captivity for over 100 years, but abnormal 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 maturity. Nutrition may contribute to these problems, as the diets of wild and captive tuatara are known to differ. Blood samples were taken from wild tuatara on Stephens Island during February, May, August, November 1992 and January 1993, and from captive tuatara in New Zealand zoos during February/March and Juiy/August 1992. The blood plasma was analysed for concentrations of total cholesterol and triacylglycerol. No significant differences between males and females were found in captive 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 variation in either of these lipids for the wild juveniles, nor for cholesterol concentrations in captive juveniles. However, triacylglycerol levels of captive juveniles showed significant variationbetween February and August. Differences in plasma lipid concentrations between wild and captive tuatara may result from differences in diets. © 1994 Taylor & Francis Group, LLC.