Does reproductive effort influence the metabolic rate of Tomodon dorsatus snakes?

Abstract

In Squamate reptiles, vitellogenesis in females is marked by an increase in the number and size of follicles, leading to an increase in aerobic metabolism to support the rising energy demand during reproductive activity. Male gametes are smaller than female gametes, and spermiogenesis requires less energy than vitellogenesis. This investigation compares the relationship between aerobic metabolism and reproductive effort in male and female viviparous Tomodon dorsatus snakes. We evaluated the influence of the males' and females' reproductive stages, along with the masses of follicles and testicles, on their aerobic metabolic rate. Our findings show that females have higher maintenance cost of pregnancy than metabolic costs of vitellogenesis. In males, we found no evidence of the reproductive effort influencing aerobic metabolic rates. In T. dorsatus, females have a long period of development and high fecundity. Therefore, the metabolic costs of vitellogenesis represent a critical component in the reproductive effort. On the other hand, males of T. dorsatus maintain a similar mass of gonads throughout the year with constant energy demand. These results reflect the difference in reproductive efforts between females and males of T. dorsatus.