Thalassoma lunare is also named the Moon Wrasse because of its yellow caudal fin shapes like crescent moon with long upper and lower lobes. It is an inhabitant of coral reefs and surrounding areas at depths from 1 to 20. T. lunare is the most abundant wrasse species in the Persian Gulf. This species can reach 16 cm in total length in Iran, Persian Gulf, Kish Island. Moon wrasses are active fish, said to be moving all day long. They are also territorial, nipping, chasing, and otherwise harassing fish that get in their way. Being diurnal, wrasses have strong vision, although they also have a decent sense of smell. At night, they rest in niches often under rocks or other such structures. If needed, a moon wrasse may dig out a space under a rock by repeatedly swimming through it until it fits without struggle. They are protogynous hermaphrodites, all starting off as females and changing to males, a process which, for the moon wrasse, takes only 10 days. Some moon wrasses live in groups consisted of a dominant male, and a "harem" of about a dozen other wrasses, some female and some male. The alpha male is more brightly colored, and at every low tide hour, changes from green to blue, and goes into a show of attacking and nipping all the other wrasses. This is his way of showing his dominance to the rest of the males and keeping the females in check. During breeding season and before high tide, the alpha male turns completely blue, gathers up every single female, and the spawning frenzy begins.