Adaptations help reef fish to survive

PUBLISHED : Tuesday, 16 November, 1999, 12:00am
UPDATED : Tuesday, 16 November, 1999, 12:00am

Fish that live in coral reefs have a multitude of special physical adaptations for their environment.

Goatfish have two long chin barbels at the tip of the mouth which look like a 'beard'. In fact, these are sensitive receptors used to locate food and mates.

Reef fish that are active at night have big eyes to help them find prey and mates in the dark. These include the Apogins fish we use commercially for food.

The thin shrimpfish, which has a long stripe, tries to blend in with a sea urchin's spines for protection from potential predators. It hovers over a sea urchin with its head pointing downwards to camouflage itself.

Butterfly fish have fake eye spots, black dots on the posterior part of the body, to confuse predators into thinking they are swimming in the opposite direction, while their real eyes are disguised by a dark band or other colour patterns.

Seahorses and pipefish have tube-like mouth parts which act like a vacuum cleaner to catch prey, such as crustaceans, by making sudden sucking movements.

Parrot fish have beak-like mouths. The teeth on the upper and lower jaws are fused together and look like a parrot's beak. It helps them chop and grind the algae growing on the rough surface of the corals that they eat into a fine paste.

The lionfish's long sharp spines and bright colouring are a clear danger signal. Some species occasionally attack humans.

Anemone fish live among the stinging tentacles of anemones without being harmed. The fish secretes a mucus coating around its body which protects it from the anemone's stings. Anemones provide protection for the anemone fish who remove parasite and debris for the anemones in return. This amazing relationship is known as mutualism, a type of symbiotic relationship.

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