Somanniathelphusa is a genus of freshwater crabs found in southeast China, Taiwan, and southeast Asia. It includes the following species: * Naiyanetr & Dai, 1997 * Naiyanetr & Dai, 1997 * Dai & Xing, 1994 * Dai, Peng & Zhou, 1994 * Tai, Song, He, Cao, Xu & Zhong, 1975 * Yeo & Nguyen, 1999: Vietnam * Ng & Dudgeon, 1992 * Dai, Peng & Zhou, 1994 * (Alcock, 1909) * Naiyanetr & Dai, 1997 * Dai & Xing, 1994 * Naiyanetr & Dai, 1997 * Dai, Peng & Zhou, 1994 * Dang, 1975: Vietnam * Ng, 1995 * Dai, Peng & Zhou, 1994 * Naiyanetr & Dai, 1997 * Naiyanetr & Dai, 1997 * Naiyanetr & Dai, 1997 * Ng & Kosuge, 1995: Vietnam * (Fabricius, 1798): Vietnam * Dai & Xing, 1994 * Dai, Peng & Zhou, 1994 * Somanniathelphusa sinensis (H. Milne-Edwards, 1853): China, Vietn