Vissian

The Vissians were a humanoid species from the planet Vissia. They were notable for having three genders. First contact was made by the NX-01 Enterprise in 2153. In 2156, the Vissians denied Jonathan Archer's request that they enter the Earth-Romulan War on Earth's side.

At least one Vissian woman served as an engineer in the Federation Starfleet, serving under Captain Montgomery Scott in the S.C.E.. She was berated by him for not completing a report on a Martian time corridor generator fast enough.