Along the eastern coast of Australia there is the Great Barrier Reef, which extends for 2000 km. It is built by the coral polyp.
The Great Barrier Reef is near 18 mln years old. The area of the reef is more than 230 thousand sq km.
Coral reefs are usually called the “live rocks”. They are built of thousands of polyps, which are closely set to each other. They make up a lime base and can get off easily.
They differ from each other greatly. There are many kinds of corals.
Among the coral polyps there live a lot of sea animals. You can find here fish of orange, yellow, pink, blue, violet and green colours.
Another living organism here is a sponge. It is a “ sitting” animal. It can be of different forms. They eat coral polyps.
A lot of star- fishes of different colours live in the reef. They also eat coral polyps.
Among the corals swims a unique animal – a horse- fish. It looks like a chess figure and has a wonderful tail, that helps it swim very fast. The tail can also help the horse-fish to hold to some plant or a coral polyp. Males, not females, usually bring up babies.
There are 400 kinds of corals in the Great Barrier Reef. 200 kinds of shells live there. Over 2000 kinds of fish swim among the corals.