Zhangixalus schlegelii (Günther, 1858)

Size

Males of Zhangixalus schlegelii measure 32–43 mm (1.3–1.7 in) in snout–vent length, while females measure 43–53 mm (1.7–2.1 in).

Male Secondary Sexual Characteristics

Males have yellowish white nuptial pads, a darkly colored throat, and a pair of slit-like vocal openings.

Limb Webbing and Discs

The webbing on the fingers and toes is not well developed; the finger tips have truncated discs with circummarginal grooves.

Dorsal Skin Texture

The dorsal skin is almost completely smooth.

Skin Folds

The supra-tympanic fold is prominent, but there is no dorsolateral fold.

Habitat and Breeding Sites

This species occurs in temperate wetlands and forests ranging from hilly to lowland areas, and it especially favors paddy fields, which are its main breeding site.

Conservation Status

The International Union for Conservation of Nature (IUCN) does not consider this species threatened.

Reproductive Nest Type

Zhangixalus schlegelii (formerly classified as Rhacophorus schlegelii) reproduces by building underground foam nests.

Nest Location Variation

In Japan, this nest-making frog has been reported to occasionally lay eggs among leaves on bushes or trees, but its usual behavior is to create a nest underground.

Post-Hibernation Nest Excavation

After awakening from hibernation, the frogs crawl along the edges of rice fields and swamps to dig out holes above the water level.

Nest Hole Occupation

The much smaller male is carried by the female, and both become buried in a hole 6–9 cm wide, located 10–15 cm above the water surface.

Nest Cavity Preparation

The female smooths the interior of this nest cavity with her movements.

Foam Mass Production

At night, she produces a tough, elastic ball of white, air bubble-filled material 6–7 cm thick, which emerges from her cloaca alongside the eggs.

Foam Mass Function

This foam mass provides moisture and air for developing offspring.

Female Foam Kneading Behavior

The female kneads the mass thoroughly with distinctive foot movements: she stretches and closes her toes to mix the sticky material with air, breaking large bubbles into progressively smaller bubbles of foam.

Male Foam Manipulation Behavior

The male makes similar foot movements to push the foam backward, leaving eggs unobstructed for subsequent fertilization.

Post-Fertilization Adult Behavior

Once the eggs are fertilized and surrounded by this protective, aerating mass, the adult frogs exit the nest and move to live among trees.

Foam Mass Degradation

Over time, the foam mass gradually liquefies.

Offspring Dispersal

The liquid flows out through the opening the parents left when exiting the nest, carrying the developed young out into the surrounding open water.