The clownfish is best known for its symbiotic relationship with certain types of sea anemones. The fish grow up and live protected from predators among the anemone's tentacles. The anemones do not sting the clownfish with their tentacles because the fish provide protection and bring food to the anemone.
This fish has a unique way of warding off predators. When threatened, it flares a flap, or opercula, on either side of its head. This makes the fish appear too large to be swallowed.
Concealed in protective camouflage, this big mouthed, fine-toothed fish eats large bites of turf algae. It eats up to three times its weight in algae a day.
This small, bottom-dwelling fish is one of the most colorful on the reef. The deep blues and greens create paisley-like patterns that help it blend into the rocks.
Found in the lagoon or mangrove, seahorses wrap their prehensile tails around grasses or seaweed to anchor themselves. Unlike most fish that swim horizontally, they swim with their bodies straight up and down. Also of interest are their mating habits. The female deposits eggs into a pouch on the male. After about six weeks, depending on the species, the male gives birth to anywhere from a few to several hundred baby seahorses.
The jawfish is always busy excavating and repairing the tunnels in which it lives. Jawfish are mouthbrooders. The male carries the eggs in its mouth until they hatch and will often bob outside the opening of the tunnel with its mouth open to provide oxygen to the eggs.
This large bright blue fish belongs to a group known as a surgeon or doctor fish because of two scalpel sharp scales near the base of its tail. Tangs use these scales when sparring with each other. They extend the scales perpendicular to their bodies and try to cut their rivals by backing into them.
The males of this species are distinguished by their red color and the solid square of pink on their sides. The multiple females, or harem, that follow a single male are much smaller and are mostly yellow or orange.
This shrimp often hangs upside-down from rock ledges or corals, waving its antennae to attract fish. The shrimp has a symbiotic relationship with fish. The shrimp touches the fish with its antenna. Then it reaches out to the fish, and eats parasites and dead skin off it. The shrimp gets a meal and the fish gets cleaned.
This large species of snail spends its time using a long trunklike appendage to graze for algae. This snail is also called the fencing shell because it can use the solid disk on its foot to fend off some predators.
Anemones are related to corals in that they both have polyps that are used for obtaining food. Both also use individual stinging cells to help them catch prey. Unlike corals, however, anemones can detach themselves from the reef. They can use a sucker disk at the base of their bodies to slide along the reef bottom.
Unlike most jellyfish, the upside-down jellyfish spend most of their time upside-down on the lagoon or mangrove floor. Inside their center tentacles live photosynthetic algae that need sunlight to survive. In return for the jellyfish's light-gathering, upside-down state, the algae provide the jellyfish with much needed nutrients. They also constantly pulse to draw oxygen rich water and food particles toward themselves.
This stony coral is famous for its stinging sweeper tentacles that create a protective perimeter. About 1 in 20 tentacles is a sweeper that can stretch to 20 to 30 times its normal length.
Fan worms live in self-made tubes on rocks. They are suspension feeders. They eat organic nutrients suspended in water. A simple eye in the center of the fan enables the worms to detect shadows of predators, allowing for a quick retreat into their tubes.
The sea cucumber uses small tube feet to climb to prominent points of the reef where it will extend its tentacles to catch plankton as they drift by. The sea cucumber then pulls the tentacles one by one into its mouth and pulls the food off of them. Also, some sea cucumbers, when agitated, can release a toxin strong enough to kill all the fish in the area.
This invertebrate has an obvious defense against predators: spines. The spines of some sea urchins carry toxins that can make a puncture wound very painful. However, parrot fish like to nip away at these protective points to reach the body.