Complete Embryonic and Larval Stages of Rana sakuraii (Ranidae), a Species that Metamorphoses without Feeding

Abstract

The normal development of the brown frog Rana sakuraii is observed from oocyte to completion of metamorphosis in the laboratory at 15±2°C. Tadpoles of this species can develop completely without any food. Their development is divided into 40 stages and this paper provides descriptions and illustrations of the external features at each stage. After hatching, some developmental events occur simultaneously and elongation of hindlimb buds and toe formation are relatively rapid. On the average, the tadpoles reach the stage 36 with their maximum total length 22.8 mm after 43.9 days. They complete metamorphosis after 56.5 days, reaching the final stage 40 with 8.0 mm in snout to vent length. The labial teeth development of this non-feeding tadpole is generally weak and the formula at a given stage is greatly variable among individuals.