Abstract
Six of Japanese tree frogs(Hyla japonica)were sent to the Russian space station MIR (FRIS experiment group, 1990 and Izumi-Kurotani, et al., 1991). Their postures, movements, behaviors were observed under microgravity. Floating frogs showed a typical posture in space. They stretched four legs out and bent their body backward. Response behaviors to the external stimuli were similar to those on ground. When frogs stayed on the surface of something, many frogs bent their neck backward. Adaptation to microgravity was expressed as improvement of landing after jumping in later experiment. After 8 days on orbit, all the tree frogs were recovered alive to ground. Readaptation to normal gravity was also investigated.
