In the deep-sea hydrothermal systems of the Okinawa Trough, North-West Pacific, several active vent fields have been detected running from north-east to south-west at a depth of 700-2000 m. A number of amphipod individuals were collected from the north-east of the Okinawa Trough at a depth of about 1000 m, and after careful examination were identified as a new genus and species belonging to the Melitidae. Here, a formal morphological description of the new species and a discussion of the relationships of the new genus within Melitidae are presented.