Hydrochus binodosus Motschulsky, 1860b

Hydrochus binodosus Motschulsky, 1860b: 104; d’Orchymont 1922: 624; Jäch 1995: 182; Biswas & Mukhopadhyay 1995: 149; Hansen 1999a: 53; Ghosh et al. 2000: 45; Ghosh et al. 2016: 23; Jia & Wu 1999: 308; Mukhopadhyay 2007: 406; Jaiswal 2012: 39; Jaiswal et al. 2013: 25; Jaiswal et al. 2014: 98; Mukhopadhyay 2015: 387; Anamika et al. 2021: 185.

Type locality: Ind. Or. (Jäch 1995).

Distribution in India: Andhra Pradesh (Chittoor), Assam (Dibrugarh), Madhya Pradesh (Jabalpur), Odisha (Chilika Lake), Tripura (Rudrasagar), Telangana (Hyderabad, Durgam Cheruvu), Uttar Pradesh (Etah), and West Bengal (Kolkata, Hugli).

Global distribution: China, India, Indonesia, Sri Lanka, and Vietnam.

Hydrochus japonicus Sharp, 1873

Hydrochus japonicus Sharp, 1873: 64; Jäch 1995: 182; Hansen 1999a: 58; Fikáček et al. 2015b: 36.

Hydrochous japonicus: Zaitzev 1908a: 334.

Hydrochus annamita Régimbart, 1903b: 64; d’Orchymont 1922: 624; Jäch 1995: 182; Mukhopadhyay & Sengupta 2004: 451; Devi et al. 2017: 7.

Type locality: Japan, Kyushu, Nagasaki (Hansen 1999a).

Distribution in India: Assam (Dibrugarh) and Manipur (Bishnupur, Loktak Lake, Keibul–Lamjo National Park, Chandanpur, Imphal, Senapati).

Global distribution: Australian (New Guinea), China, India, Japan, Philippines, Taiwan, Thailand, and Vietnam.