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4 Animals That Live in the Coral Reef

A coral reef often looks like a big rock formation but in fact is mostly a large community of connected living organisms. Solcomhouse, an environmental information site, calls coral reefs the rain forests of the ocean, providing as much as 25 percent of all sea life a home. Coral reefs get their energy from the sun, and occur in relatively shallow depths of warmer tropical waters.

Cnidaria
- Coral, sea anemones and jelly fish all belong to the Cnidaria family, meaning their skeletal material is embedded in the tissue or encases the animal. Corals are fixed animals that do not move; an actual coral is made up of hundreds of thousands of tiny individual animals called polyps. The calcium carbonate shell they create is what houses the coral, and builds the reef as coral upon coral grow and die in layers. Most coral live in symbiosis with zooxanthellae, a form of algae. The algae produce the nutrients the coral need through photosynthesis; the coral provide the algae with the compounds necessary to create the photosynthesis. Coral bleaching occurs because coral take their color from the zooxanthellae, and if the coral is stressed and expels the organisms, it loses the color of the algae as it dies.
Worms
- A large number of worm species live on reefs. Some bore into the coral, others -- like flat worms -- live in crevices in the reef. Ocean worms are segmented and much like earth worms, but have evolved in a variety of appearances. Tube worms like the feather duster and Christmas tree worm have a vivid array of tentacles they wave about to collect food, but can retract into their hard shelled tube when threatened. Others such as bristle worm move all over the reef floor and carry a painful sting in their bristles to ward off predators.
Mollusks
- Octopus, squid, clams, scallops, and even carnivorous snails are mollusks that inhabit the reef in large numbers. Octopus and squid live in crevices and are predatory animals. Scallops and clams are bi-valve creatures that filter plankton from the water as food. Prized as food themselves, clams can also produce pearls, and scallops are prized for their beautiful shells in addition to their sweet taste. Carnivorous snails are an interesting reef inhabitant. Often brightly colored they can bore into the shells of other reef inhabitants and eat them.
Fish
- While some fish such as sharks visit reefs for a meal, others live on the reef full time. Wrasse are cigar-shaped fish with a specific species as a cleaner fish. These wrasse station themselves at certain locations that become known to larger fish, who stop in for a cleaning of parasites they may carry, which the wrasse eat. Other reef fish include a beautiful array of fish such as angelfish, damselfish, clownfish and seahorses. One mighty reef inhabitant is the moray eel, which is a fish, and widely recognized for it's craggy features and sharp teeth.

Animals & Science