Coral is coral polyps, is a marine cylindrical coelenterates, in the white larval stage will automatically fixed on the calcareous remains of the ancestral coral pile, coral is coral polyps secretion of the shell, the chemical composition of coral is mainly CaCO3, to the microcrystalline calcite aggregates in the form of the composition of the composition of a certain amount of organic matter, the morphology of the dendrites, with longitudinal striations on the top of the coral, each monomer coral Cross-section of concentric circles and radial stripes, the color is often white, there are a small number of blue and black, coral is not only like the image of branches, bright and beautiful colors, can be used as decorations, and also has a high medicinal value.

Pictures are as follows:

One, the appearance of features

Coral image like branches, bright and beautiful colors, can be used as decorations. Gem grade coral is red in color

Coral Reef? (18)

, pink, orange-red. The red color is formed due to coral absorbing about 1% of iron oxide in seawater during the growth process, and the black color is due to the presence of organic matter. It has a glassy to waxy luster and is opaque to translucent.

Species

Anthozoa

Corals are the largest of the phylum Coelenterata, all marine.

Coral reefs

All are hydrozoan monads or groups of animals, with no jellyfish-type generations in their life histories. Coralline hydrozoan structure is more complex than hydrozoan, the body is two radial symmetry. Common species include red coral (Corallium rubrum), fine-fingered anemone (Metridium), and sea cactus (Cavernularia).

The phylum Coelenterata is known to have about 9,000 species, which are usually divided into three orders, namely, Hydrozoa, with about 2,700 species; Scyphozoa, with just over 200 species; and Anthozoa, with over 6,100 species.

Coral in the coelacanth is a general term, daily life, where the shape of the peculiar, delicate and delicate and from the sea, people will be crowned "coral (coral)", where the "red", collectively referred to as "red coral". "red coral". Coral usually includes soft coral, willow coral, red coral, stony coral, horn coral, hydroid coral, pale coral and pith coral. Some people mistakenly call the soft-bodied gills (Pennatulacea) and groups of sea anemones (Zoantharian) also mistakenly called "coral".

There are about 1,000 species of stony corals (Madreporaria or Scleractinia), about 100 species of black corals and spiny corals (Antipatharia), about 1,200 species of willow corals (Gorgonacea), and about 1,200 species of blue corals (Coenothecalia). Coenothecalia]) only one species exists.

Stony corals are the best known and most widely distributed species, living singly or in groups. Like black and spiny corals, they have septa of 6 or multiples of 6, and simple, non-pinnate tentacles

Black and spiny corals are whip-like, pinnate, treelike, or bottle-brush-like, and are found in the Mediterranean Sea, the West Indies, and the coastal waters of Panama.

Due to environmental pollution, a component of the air that makes corals susceptible to death is present in some coral areas, and as a result, coral species and populations have declined dramatically around the world.