Plasticity in metamorphic traits of Chinese brown frog (Rana chensinensis) tadpoles: the interactive effects of food level and rearing temperature

Larval amphibians are especially likely to encounter variation in temperature and resource availability because they live in a variety of aquatic habitats. In this study, plasticity in growth rates, survivorship, age and size at metamorphosis were examined in the Chinese brown frog (Rana chensinensis) under different combinations of rearing temperature and food level. Tadpoles reared at 23.2°C had larger mass at metamorphosis and a longer larval period than tadpoles reared at 25.3 and 28.1°C. High food level shortened the larval period and produced a larger size at metamorphosis. The interaction of rearing temperature and food level significantly influenced the growth and survival of Chinese brown frog tadpoles. At a low food level, tadpoles reared at 23.2°C displayed faster growth than tadpoles reared at the higher temperatures, and tadpoles had lower survival at 28.1°C than at the lower temperatures. Therefore, global warming or local manipulations of the environment could limit growth and development of Chinese brown frog tadpoles, resulting in low survival, but food availability may mediate effects of temperature. We suggest that Chinese brown frog tadpoles prefer cool a temperature and high food level for longer larval periods to capitalize on the opportunity of entering the terrestrial habitat with a larger body size.