No community can normally function without predators. The most known predators of coral reef are large morays (Gymnothorax sp.) (MURAENIDAE), with their special serpentine-like shape of the body, very strong jaws and numerous needle-shaped teeth. Morays hunt at night, and at daytime they hid in hiatuses of corals and in underwater mainsails. The colouring of morays is often cryptic, and the inexperienced divers frequently do not see hidden morays and may be attacked. In this case the food remnants in the teeth of morays may cause a serious infection. However local people feed on many species of morays.

Groupers (Cephalopholis sp.) (SERRANIDAE) are considered to be the most common predators of a coral reef. They are nocturnal. Their diet consists of the crabs, shrimps, small fishes. Some groupers may reach the very big size, up to two meter in length and more than 300 kg in weight. They occupy the same shelters for a long time and people may encounter the same individuals in the same places for several years.

There are a lot of so-called cleaner fishes among small wrasses (LABRIDAE), which clean large fishes from ectoparasites. One of them, blue streak wrasse (Labroides dimidiatus) is presented in "Exotarium". Wrasses permanently live in a particular place of a reef, and their predatory "clients" visit them when they need "hygienic procedures". The predators identify wrasses by their special colour and behaviour. Inviting a fish for cleaning, wrasse is "dancing" and never tries to flee to prevent an attack.