Coral Reef Fish and Sealife

Of all the marine fishes, coral reef fishes are the most colourful. Their world is a bewildering confusion of amazing patterned fish, with an overwhelming number and diversity. There are more species of fish on the coral reef than in any other watery environment in the world. We do not fully understand why there is such a wide diversity of fish species but we do know that life forms evolve or adapt to their environment and in response to competition for space and food. 

Coral fishes have evolved together with the reef building corals, responding and adapting with them to produce the closely integrated ecosystem we see today. Reef fishes can best be grouped according to their feeding patterns. Some reef fish feed on algae, spending the daylight hours browsing on the thin coating of algae that adheres to dead coral rock surfaces. Large numbers of shoaling reef fish species in brightly coloured clouds feed on tiny floating animals the zooplankton, hovering on the reef edge where the richest concentrations occur.

Some of the most beautiful reef fishes including Angelfishes and Butterflyfishes, actually feed on coral polyps and sponges. Another important group, containing a large number of fish families such as Snappers, Puffers, Triggers and some Wrasses and Emperors, feed on other invertebrate life forms, such as molluscs, crustaceans and echinoderms. In the final group are the marine predators that feed mainly on other fish and these include the Sharks, Groupers, Moray Eels and Barracudas.

The Queen Parrotfish is a daytime feeding herbivore that grazes on algae. Colourful Fairy Basslets or Jewelfishes are tiny cousins of the large predatory groupers. These lively fish found in the Indian and Pacific Oceans feed on upwelling zooplankton.

Triggerfishes are true opportunists flitting across the reef searching for a quick meal. They feed on the most unlikely fare the Queen Triggerfish specializes on long spined Diadema Sea Urchins. The Triggerfish from the tropical western Atlantic grows up to 50cm(20in) long. Angelfishes are common in shallow reef areas in all parts of the world.

The adult Caribbean Rock Beauty is very striking, with a dark area covering two thirds of its vivid yellow body but juveniles are yellow with just a small dark spot. Like many Angelfishes the Rock Beauty feeds on sponges.

Tiny bright green Chromis live in small shoals close to spiky growths of stag horn corals, into which they retreat for safety, these fishes feed on zooplankton. Classifying reef fishes according to their feeding pattern is not so easy with opportunistic feeders, such as the Surgeonfishes. The Flagtail Surgeonfish or Regal Tang feeds on filamentous algae. The name 'surgeon' comes from the sharp scalpels at the base of the tail.

Groupers such as the Panama Graysby inhabits off the Galapagos are located at the top of the food chain together with other large predators including Sharks, Barracudas and Moray Eels. They are territorial animals that lie in wait for their prey such as small fish and crustaceans.