Marsh frog - Marsh frog

A frog of the family Ranidae in the order Anura in the class Amphibians. It is an Oriental frog that is widely distributed from India to Southeast Asia. In Japan, it is found in Honshu, Shikoku, Kyushu, and the Ryukyu Islands west of the Tokai region, and in China, south of the Yellow River. It is a lowland frog that is not found in mountainous areas. It is about 4 cm long. Its back is brown with irregular dark spots and many vertical ridges. The ventral surface is white and smooth. The male's throat is blackish. In mainland Japan, there are individuals with a thin yellow-white dorsal line, but they are not found in the Amami Islands or Okinawa Islands. Those in the Yaeyama Islands are large, reaching a body length of over 6 cm, and many individuals with a dorsal line. They breed in rice paddies, wetlands, and puddles in summer. They have a loud call. The eggs are about 1 mm in diameter, and there are about 1,000 eggs. The egg masses are small and irregular in shape.

[Mitsuru Kuramoto]

Source: Shogakukan Encyclopedia Nipponica About Encyclopedia Nipponica Information | Legend

両生綱無尾目アカガエル科のカエル。インドから東南アジアにかけて広く分布する東洋区系のカエルで、日本では東海地方以西の本州、四国、九州、琉球(りゅうきゅう)諸島、中国では黄河以南に分布する。低地性で山間部にはいない。体長4センチメートル前後。背面は褐色で不規則な暗斑(あんはん)があり、多数の縦隆起がある。腹面は白色で平滑。雄ののどは黒っぽい。日本内地には黄白色の細い背中線をもつ個体がいるが、奄美(あまみ)諸島、沖縄諸島にはいない。八重山(やえやま)諸島のものは大形で体長6センチメートル以上に達し、背中線をもつ個体が多い。夏期に水田や湿地、水たまりで繁殖する。鳴き声は大きい。卵径約1ミリメートル、卵数約1000個。卵塊は小さく不定形である。

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