Wrasses are difficult to identify. Many species could be identified by their live colouration, but they vary between juveniles and adults and with sex change. The colours also change after death. They are also often being confused as parrotfishes. Most of them mature first as females and then sexually transform into males, usually accompanied by a change in colour phase. In species where 2 adult colour phases are known, the first is termed “initial phase” (IP), the second, “terminal phase” (TP). Initial phases may thus be male or female, while terminal phases are invariably male.
Wrasses are most often found on or in the vicinity of coral reefs, rocky reefs, sand, grass, and algae, and are usually most abundant in shallow waters. Some species are found at depths of 100 m but are rarely found in muddy areas. Wrasses are diurnal, taking cover in reef crevices or burrowing into the sediment at night. They have a diverse feeding habits. Some of them carnivores, some planktivores, and some small species remove ectoparasites and dead tissues of larger fishes.
There are 70 genera and about 509 species of Labridae worldwide. Malaysia has at least 25 genera and 70 species.