Type species. Opecarcinus hypostegus (Shaw & Hopkins, 1977) [Type locality: Florida Middle Ground, west of Tarpon Springs, Gulf of Mexico].
Remarks. Opecarcinus hypostegus is the only Atlantic species of its genus. The remaining eight species in Opecarcinus are Indo-West Pacific in distribution (Kropp 1989; Meij 2014b). Xu et al. (2021) estimated that Opecarcinus harbors about 15 undescribed species and several potential species complexes.