Japanese Brown Frog

Japanese Brown Frog (Rana japonica) is a true brown frog with a streamlined body and dark mask extending behind the eye. Identification should combine body shape, skin texture, colour pattern, toe structure and locality because related frogs can be extremely similar. Claims are limited to the species accounts opened for this batch (Wikipedia, general species account). Field identification should remain cautious when diagnostic measurements or clear photographs are unavailable.

It is endemic to Japan and uses grassland, rivers, swamps, irrigated land and seasonally flooded agricultural habitats. Information absent from those species-level sources is omitted rather than borrowed from relatives. Japanese occurrence follows the site's catalogue and the opened distribution account, without using IUCN conservation material (Wikipedia, general species account; Wildlife of Japan occurrence records). This wording keeps gaps in the available species evidence explicit rather than concealing them.