Body Size and Age Determination by Skeletochronology of the Brown Frog Rana tagoi tagoi in Southwestern Kanto

Abstract

Body size and age structures of two breeding populations of Rana tagoi tagoi were studied in southwestern Kanto. The mean snout-vent length of males and females was 42.2 and 44.2mm in Kanagawa, and 41.7 and 42.2mm in Tokyo, respectively. The populations studied exhibited almost no sexual dimorphism in body size. Rana. t. tagoi was successfully aged by skeletochronology using phalanges. The breeding adults were 2-4yr old and the age at first reproduction was estimated to be 2-3yr. Their lifetime growth schedule was also estimated, based on the relationship between body size and age.