Intraspecific variation of temperature-induced effects on metamorphosis in the pool frog (Rana lessonae)

Abstract

Understanding the factors that affect the process of metamorphosis in species with complex life cycles, and in particular their variation within and among populations, has been rarely explored until recently. We examined the effects of temperature environment on several metamorphic characteristics in three populations of the pool frog ( Rana lessonae Camerano, 1882) by rearing individuals at two temperature environments (20 and 25 °C). Higher temperature shortened the metamorphic period and reduced the absolute mass loss, although there was no difference between the temperatures in the percentage of mass lost. No differences among the populations were detected, but there was significant intrapopulation variation both in the mean and in the plasticity for the duration of metamorphosis. These results indicate that several aspects of metamorphosis are plastic in amphibians, these traits may have considerable intrapopulation variation, and that temperature is a strong factor affecting the process of metamorphosis.