Dryophytes japonicus (Günther, 1859)

Body Length

Japanese tree frogs (Dryophytes japonicus) have an average body length of 32.81±0.96 mm.

Skull Dimensions

Their average skull width is 12.02±0.36 mm, and their average skull length is 9.38±0.14 mm.

Body Coloration

The dorsal (upper) side of their body is green or brown, while the ventral (under) side is white.

Distinguishing Mark

A defining characteristic of this species is a dark spot on the upper lip, positioned below the eye.

Sexual Size Dimorphism

On average, female Japanese tree frogs are larger than males.

Male Secondary Trait

Males have a dark vocal sac.

Geographic Range

Japanese tree frogs occur across many parts of Asia, including Japan, China, Korea, Mongolia, and Russia.

Habitat Types

They live in forested environments, bushlands, meadows, swamps, and river valleys.

Habitat Requirements

Like most frog species, Japanese tree frogs occupy areas that have both aquatic and terrestrial features, because both water and land are required to complete their life cycle.

Modified Habitat Use

When their native habitats become less available, Japanese tree frogs will settle in rice paddies.

Rice Paddy Preference

They are able to live successfully in these rice paddies, and show a clear preference for sites with dense vegetation.

Anti-Predator Toxin Production

To defend themselves against predators in their arboreal habitats, Japanese tree frogs produce special Anntoxin-like neurotoxins from their skin.

Anntoxin Properties

Anntoxin is a 60-residue toxic peptide that inhibits ion channels, including tetrodotoxin-sensitive voltage-gated sodium channels.

Toxin Effects

While these peptides have analgesic properties when they bind to ion channels, they can harm or kill predators that consume the frog's skin.

Toxin Predator Deterrence

This mechanism discourages predators from hunting these frogs in the future.