說明/ 雄蛙體長2.3–2.5 公分，雌蛙2.6–2.8 公分。頭長寬略等， 吻端尖圓。鼓膜不明顯，顳褶延伸到腹面。體色變化頗大，灰黑色或紅褐色。身體呈三角形，背部中間有一條黃色中線，中線旁有不規則黑色小括弧「(　)」狀花紋，故又稱小弧斑姬蛙。常見於開墾地水域及草澤中，與相似種小雨蛙比較，後者趾端沒有吸盤背中央也沒有括弧狀花紋。鳴叫聲為拉長之「滴ㄟ – 滴ㄟ – 滴ㄟ–」聲。（彭楨儒攝）
Males 2.3-2.5 in length, females 2.6-2.8 cm. The width and length of the head are roughly the same. The tympanum is not visible. The temporal fold reaches the belly. Individuals vary greatly in color, including greyish-black or reddish-brown. The body is triangular, with a yellow line running through the middle of the back, accompanied by irregular black markings that are shaped like parentheses, giving it the Chinese name “Small Parenthesis Frog.” It is often seen in the ponds near cultivated lands and grasslands. Ornata Narrow-mouthed Toads, an allied species, do not have suckers on their toes or parenthesis markings. It makes elongated “diei-diei-diei” calls. (Photo courtesy of Peng Zhen-ru)