The Seleneans were a race from the planet Selene. Decisions tend to be made by Pod Mothers who then design a crèche based upon need. In their natural state, the Selenean people were golden and had large defensive "qills" on their spine. When they joined the United Federation of Planets, the Pod Mothers designed their offspring to resemble the Federation's dominant species, only to return to their natural state in times of danger. The crèche name (last name) comes before the given name. (DS9 - Prophecy and Change short story: "Chiaroscuro", TTN novel: Sword of Damocles)
While Seleneans were, technically, a neuter species, reproducing asexually via group linking and pod generation, post contact with and induction into the Federation of Planets, many generations were designed with Humanoid, Klingonoid and Vulcanoid gender characteristics in order to facilitate easy acceptance by the dominant species of the UFP. Whether this modification was merely cosmetic or induces true genetic similarity with the mimicked species is not known.
Selenean brains had five lobes. No matter what form they took, all Seleneans had two unvaried identifying characteristics: skin that appeared to be made of polished gold and a minimum of two bulbous, turquoise eyes that resembled large gemstones.
Seleneans did not cry nor blink involuntarily.
Seleneans were chemopaths, using “linking spines” to directly alter the chemistry of connected brains in order to share information and to breed.
There were, at maximum, seventeen Seleneans in Starfleet from various crèches with a diaspora of 2500 more spread out among the worlds of the Federation.
While not as stoic as Vulcans, Seleneans were extremely analytical, preferring reasoned action over intuitive. They were naturally polite, seeking never to offend any being under any circumstances if they could avoid it. This may have been a cultural characteristic rather than genetically hardwired.