card
145

gorgonian fan coral

OLogy Series
animal
card
145

gorgonian fan coral

OLogy Series
animal

With vibrant colors and fantastic shapes, coral reefs are a breathtaking sight. These underwater structures are actually colonies of tiny animals called coral polyps. Gorgonian fan corals look like beautiful trees with many thin branches. Most species have an internal, horny skeleton made from proteins. Like trees, corals are quite flexible, and can be seen waving in the current.

Coral Reefs in Crisis
Reef-like structures have existed on Earth for at least 200 million years. Corals that we know were the early ancestors of the species we see today date back to about 240 million years ago. But coral reefs are now in great danger. Warmer waters, caused by climate changes associated with El Nino, can kill many corals. But humans also pose a very serious threat to reefs. Pollution is hurting the coral polyps and other marine life in the reefs. Overfishing robs the coral reefs of marine life, upsetting the delicate ecological balance. Blast fishing -- using dynamite to bring dead fish to the surface -- destroys the reefs' structures. Even contact from the bump of a boat or the simple touch of a snorkeling diver can harm the delicate coral reefs.

Many gorgonian fan and whip corals are used to make:

jewelry

sushi

clothing

Are you right?

Correct!

Many corals -- especially black corals -- are used to make jewelry, which can sell for hundreds -- sometimes thousands -- of dollars. Because laws protect coral reefs, people who disturb them can get into very serious trouble.

Corals are:

herbivores (organisms that eat plants)

carnivores (organisms that eat animals)

omnivores (organisms that eat plants and animals)

Are you right?

Correct!

Corals are carnivores. They catch zooplankton, and they may also feed on tiny fish. They catch their prey using worm-like arms called tentacles that project from the polyps. The tentacles form a "net" that traps prey swimming by.

gorgonian fan coral
Scientific name: Ctenocella pectinata
Size: up to 20 inches tall
Diet: zooplankton (animal plankton)
Habitat: tropical waters of the eastern Indian Ocean, and western Pacific Ocean, around southeast Asia and Australia
Characteristics: colorful branching trees or fans; the polyps are tube-shaped animals

Image credits: courtesy of Eugene Weber, California Academy of Sciences.