Japanese tree frog

Appearance

"H. japonica" are on average 32.81±0.96 mm in length. They have an average skull width of 12.02±0.36 mm and an average skull length of 9.38±0.14 mm. The dorsal body of "H. japonica" is green/brown and the ventral body is white. "H. japonica" is also characterized by a dark spot on the upper lip below the eye. Female "H. japonica", on average, are larger in size compared to male "H. japonica". "H. japonica" has a dark vocal sac.

Distribution

"H. japonica" are found in many parts of Asia, specifically in Japan, China, Korea, Mongolia, and Russia. "H. japonica" inhabits forest-like environments, bushlands, meadows, swamps, and river valleys. "H. japonica", like most frog species, inhabit locations with both aquatic and terrestrial features. This is due to the necessity of the frog life cycle for both water and land.

Behavior

The behavior of "H. japonica" when exposed to microgravity has been experimentally investigated. These frogs, under such microgravity conditions, would bend their neck backwards. These frogs would also walk backwards, an observation consistent with the behavior of sick frogs. The combination of neck backwards movement and backward walking could be indicators of motion sickness in the frogs. "H. japonica" were shown to adapt to the microgravity and were able to improve their jumping and perching activity over time. "H. japonica", under micro-gravitational conditions, were also observed to attempt to eat but were unable to ingest the food. All the frogs that were sent to space were safely recovered and were observed to resume normal function after 2.5 hours back under normal gravity.

Habitat

"H. japonica" are not currently facing any notable risk of extinction and are classified by the IUCN as a species of "least concern". Notably, "H. japonica" have been sent to space in a study that explored the effect of microgravity on "H. japonica". "Hyla japonica" is synonymous with "Dryophytes japonicus".

The Japanese tree frog lives in a variety of habitats such as wetlands, forests, rivers, and mountains. They are generally located near vegetation near water sources and forests. They are carnivores that prey on insects and spiders.Their average litter size is around 340-1500 eggs, and their lifespan is usually around six years. There is an estimated 100 million of these frogs in Japan, but the accuracy is limited due to difficulty in counting.

Food

"Hyla japonica" forages in both breeding and non-breeding seasons. "H. japonica" are known to be opportunistic predators. This feature of "H. japonica" was discovered through analysis that showed a strong correlation between the relative abundance of organisms in a given environment and the prey composition "H. japonica" for that environment. A highest percentage of "H. japonica’s" diet is ants, followed by beetles and caterpillars. There does not appear to be a significant difference in the diet composition between the two sexes of "H. japonica". However, during the breeding season, males have a higher chance of having an empty stomach due to the heightened energetic cost imposed by breeding.