Seasonal variation in blood biochemistry of long-term captive Mediterranean tortoises (Testudo graeca and T hermanni).

Reference values for five blood chemistry parameters in 18 Mediterranean tortoises of two species, Testudo graeca and T hermanni, were determined on up to 10 occasions during the year. Statistically significant seasonal variations were demonstrated in blood urea and blood glucose. Seasonal variations were demonstrated in blood urea and blood glucose. Seasonal variations in total plasma proteins, lipids and cholesterol, however, were limited to gravid females. The study also suggested that three energy sources were available to the tortoise during hibernation, lipids stored in the fat body, endogenous protein degradation and glucose derived from hepatic glycogen.