Wrasses belong in the Family „Labridae" which include 60 genera and more than 500 species, making it one of the biggest fish families. Wrasses generally have elongate bodies, with a terminal mouth usually with thick lips and protruding canine teeth. The wrasse family covers a large size range from the very large blue gropers down to tiny cleaner wrasse. They are generally bottom dwellers found on rocky or coral reefs. Many are long-lived and slow-growing. Wrasses are slender often show distinct colour forms within a species which vary according to age and gender. They have elaborate courtship rituals, and some species can change their colouring and sex. Wrasses are usually very hardy and peaceful, however, a few species are extremely difficult to sustain in captivity, such as those in the genera Labroides. Some wrasses are social their entire lives, others are social as juveniles and become aggressive as adults, and yet others are aggressive their entire lives. Males are territorial and will aggressively guard their females from neighbouring males. They are active during the day, feeding upon a variety of small animals, detritus, and algae. Some species, called cleaner wrasses, pick off and eat the external parasites of larger fishes. All wrasses are diurnal and hide at night either by burying themselves in the sand or wedging themselves in crevices.