Vissians were distinguishable by crescent-shaped, segmented ridges circling the eye at the temple. Unusually (for Human standards) the Vissians had three genders: Male, female, and cogenitor. The third gender, cogenitors, made up only 3% of the population and were treated as inferior, existing only for facilitating reproduction between males and females.
Vissians were able to read, learn, and retain large amounts of new information much more quickly and easily than Humans.
History and Technology
The Vissians claimed to have developed warp drive around the 12th century. In the 2150s, Vissian space travel utilized superior warp core and sensory technology compared with Humans. They were also using photonic weapons, rechargeable with sarium microcells.
At least one ship type was capable of withstanding temperatures higher than 1100 degrees to withstand exploration within a stellar corona. Their stratopods were able to pass through the hydrogen layer of a hypergiant. The Vissians offered to modify NX-01 Enterprise's sensors to detect nucleosynthesis.
Culture and Philosophy
Vissians were more forward and liberal than Humans are with regards to copulating. They preferred to have sexual intercourse first before continuing a relationship.
Vissians tended not to travel far, believing that there was sufficient exploration close to their homeworld: this is the reason why they had not expanded particularly far from their homeworld, despite possessing warp drive far longer than Humans had. Their primary goal was to meet new species. They were willing to share their technology with the Enterprise.