Midwife toad

A frog of the family Bombinae, order Anura, class Amphibians. It is found in Germany, Switzerland, France, and the Iberian Peninsula. It is gray or brown with small dark spots and a weak dorsal ridge. It has large eyes and vertical pupils. It has a stocky body with short hind legs. It is less than 5 centimeters long. It inhabits forests, grasslands, and rocky areas at altitudes ranging from plains to 2,000 meters, hiding in holes dug with its forelegs during the day. The male and female engage in mating on land, and the male wraps the bead-like egg strings laid by the female around his hind legs or waist. The eggs are large, about 4 millimeters in diameter, and contain almost no black pigment. There are about 50 eggs. The male carries the eggs in this state, occasionally entering the water to prevent them from drying out. When the eggs hatch, they enter the water, and the tadpoles swim out of the water. Many frogs do not leave their eggs in the water, but rather the parents protect them in various ways, but this pattern is unique to the mid-morning frog. In the central and western parts of the Iberian Peninsula, the Iberian mid-morning frog A. cisternasii is distributed together with this species.

[Mitsuru Kuramoto]

Source: Shogakukan Encyclopedia Nipponica About Encyclopedia Nipponica Information | Legend

両生綱無尾目スズガエル科のカエル。ドイツ、スイス、フランス、イベリア半島に分布する。灰色または褐色で小暗斑(あんはん)があり、弱い背側隆条がある。目は大きく、瞳孔(どうこう)は垂直である。ずんぐりした体形で、後肢は短い。体長5センチメートル以下。平地から2000メートルの高度にわたる森林、草地、岩場などに生息し、日中は前肢で掘った穴に潜む。雌雄は陸上で抱接し、雄は雌の産む数珠(じゅず)状の卵紐(らんちゅう)を後肢や腰に巻き付ける。卵は大きく径約4ミリメートル、ほとんど黒色色素を含まない。卵数は約50個。雄はこの状態で卵を持ち運び、ときどき水に入って乾燥を防ぐ。孵化(ふか)期になると水に入り、オタマジャクシが水中に泳ぎ出る。卵を水中に産みっぱなしにせず、親がいろいろの方法で保護するカエルは多いが、この様式はサンバガエル独特のものである。イベリア半島中西部には、本種と重複してイベリアサンバガエルA. cisternasiiが分布する。

［倉本　満］

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