The beauty of the underwater world beckons with unusual shapes and exotic colors of inhabitants and plants. Coral reefs can be compared to a fairy tale filled with delightful treasures and fantastic characters. Often they are compared to a garden filled with bright flowers, but instead of songbirds, there are fish that have shapes that are unusual for the human eye and are decorated with patterns that you rarely see on land. Corals of bright colors - from bright pink and iridescent aquamarine to deep black - attract with unusual shapes and resistance to the destructive power of the ocean. Black coral is one of the most fragile and, due to increased human interest, one of the endangered species. In the scientific world, it is generally accepted that this outlandish beauty has adorned the Earth for more than 500 million years.
Nature of coral reefs
Upon a detailed consideration of the question “what is a coral”, you can find information that this term refers to both a living organism - a polyp, and the cementing substance with which it secretes, resembling a plant in appearance. Polyps belong to the same class as jellyfish - coelenterates, feed on plankton and live throughout the world's oceans. However, they have the ability to build grandiose reefs in shape and size only intropical waters where the temperature does not fall below 20 oC. Marine corals lead a stationary lifestyle, fixing themselves in one place and releasing their main building material of the external skeleton - calcium carbonate.
Unusual coral species
What is the coral called "sea fan"? When diving to deep-sea reefs, you can see soft corals that set the sea currents in motion. The polyps that form them build around themselves not stony, but flexible skeletons. Sometimes in shape they can form a fan, antennae resembling snakes or, growing taller than human growth, whips. At their tips are tentacles, which, opening up, absorb food for all members of the living colony.
Another unusual type of coral is tubular and cupped. It is he who creates the impression of a flowering garden on the seabed. Multi-colored "dust panicles" form polyps, the number of tentacles of which is a multiple of eight. They have a large number of stinging cells.
Types of coral reefs
One of the most famous, due to its size and complexity of the structure, the coral reef is located in the north-east of Australia. It is a barrier species, i.e., it is located at a significant (sometimes several tens of kilometers) distance from the coast. Between them is a lagoon, usually having a great depth. Fringing reefs are often found. They are located directly along the coast in shallow water. In the open space of the ocean, you canmeet coral reefs of ring-shaped formations - atolls. They are of volcanic origin and can turn into blooming islands.
Animal world of coral reefs
The organisms living in coral reefs are closely interconnected in their life activity, forming a complex ecosystem. Most of its elements are so dependent on each other that they cannot exist outside their home, just like the coral reef itself. What is a coral without oxygen, carbohydrates, constant purification from waste products? No longer a living organism. This is done by algae that live in one of the layers of polyps.
What is coral for the inhabitants of the ocean? Around the reefs, there are more than 1,500 species of fish of various sizes and shapes. Favorable habitat here and for several species of whales. Most species of sea turtles prefer to breed on coral islands, choosing them as the safest place. Favorable places for food and a variety of sea birds have not been ignored.
