On this blue planet there is a wonderful creature, they are soft and weak but accumulate solid in one breath, they are small but they create islands and reefs or tall "beacon trees", and they dye colorful underwater worlds under the clear waters. They are coral polyps, one of the oldest creatures on Earth, and they create the protagonist of the article, coral.
Corals have been with people for a long time, and the Sumerians have used red corals to make jewelry in 3000 BC; as early as the early years of the Western Han Dynasty, the King of Nanyue, located on the coast of the South China Sea, offered the "Beacon Tree" (that is, the original branch of coral) to Emperor Wen of Han. And we have a lot of misunderstandings about corals, now let xiaobian tell you what corals are?
Are corals animals or plants?
In biology, corals refer specifically to polyps in the phylum Spiny phylloscopus (Phylum Columinal) in invertebrates. Polyps are coelenterates, and the corals used to make ornaments are the bones of polyps. Corals in biology refer to polyps, which are coelenterates. According to the number of coral tentacles, polyps can be divided into: tetraphyllaceae, six-ample coral suborder, eight-ample coral suborder and transverse coral subclass. Among them, the tetraphyllaceae and transverse coral suborder lived between 500 million and 200 million years ago and are now extinct.
Corals in the suborder Hexacarp Coral and corals in the Suborder Eight Corals have different ways of secreting their bones, resulting in different bone characteristics, which determines the skeletal texture of corals and whether they can be used as gem materials.
Corals in the suborder Hexagram corals are secreted by the epidermal cells of the organism, forming calcareous cup grooves, developing septums in the invertation of the diaphragm, and the epidermal cells of the co-fleshy part of the individual also secrete calcium bones to form co-osseous bones. Its skeleton is hard, rough, large and calcified quickly, and the reef-building stony corals we know belong to the suborder Hexacarp coral.
Coral skeletons in the suborder Octopus corals, formed by deformed cells in the mesocolloid layer, are often dispersed or arranged in rows between the septum in lower species, without hard calcium carbonate bones. In some of the more evolved species, the secreted bone flakes or needles heal into axial bones, which can be coral hard protein or calcareous.
For example, the bones of red coral are delicate and have axial bones containing high magnesium and high calcium. Most of the corals in the suborder Bafang Coral have no reef-building function and belong to non-reef-building corals, such as red corals.
Reef-building corals live in shallow sea areas of 20 to 100 m, and gem corals often live between 200 and 2000 m, with a maximum depth of 4000 m. Therefore, from the growth environment, corals can also be generally divided into two categories: shallow sea corals and deep sea corals.
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The bones of polyps are all calcium?
Corals in biology refer to polyps, which are coelenterates. Corals as gemstones or crafts refer to the exoskeletons secreted by corals, corals are classified by chemical composition, can be divided into calcareous corals and corals, respectively, the bones of the eight-place coral suborder and the six-placed coral suborder, respectively.
Calcareous corals are mainly composed of calcium carbonate (82% to 87%), magnesium carbonate (6% to 7%), organic matter (1.3% to 2.5%) and water. Among them, calcium carbonate in white corals appears in the form of mineral aragonite, while calcium carbonate in red corals appears in the form of mineral calcite. Corals used as gemstones, mainly calcareous corals.
Song Meiling and Queen Elizabeth II wearing red coral jewelry.
Calcareous corals mainly include red corals, white corals and blue corals.
Blue coral is the only coral in the order oleracea, the suborder of eight corals, that can grow large skeletons, and is the only reef-building coral among gem-quality corals.
corals are mainly composed of organic matter, and the main varieties are black coral and golden coral. Both show concentric ring structures with axis of native branches around corals on cross-sectional surfaces, resembling the annual rings of trees.
The picture on the left shows live black corals in the sea, the upper right picture is a relatively complete black coral branch, and the lower right picture shows the concentric ring structure of black coral
Golden corals have a distinctive papular-like appearance on the surface and can display halos when illuminated by strong oblique light.
The papular appearance of the golden coral can be seen from the two figures on the left, and the golden coral branches in the right picture show a beautiful halo.
Corals can only be made into jewelry?
The coral is silent, indisputable, quietly sheltering life and helping those of us who are constantly hurting it.
Coral reefs sustain fishery resources, preserve biodiversity and protect our coastlines. Healthy coral reefs are like natural breakwaters, with about 70-90% of the impact of the waves absorbed or weakened when encountering coral reefs.
Some specific coral tissues, similar to human bones, have been used by surgeons since 1982 to replace bones. The gaps in the corals give space for new blood vessels to grow, perfectly repairing damaged bones.
The tranquil harmony of blue corals growing in the sea.
Inexhaustible corals?
Although coral is a renewable resource, factors such as man-made fishing damage, environmental problems and the slow growth of corals themselves make corals more and more scarce, so there is a saying that "thousands of years of coral red".
For reef-building corals, environmental pollution and greenhouse effects cause large-scale death and bleaching of coral reefs.
Gem-grade corals are in high demand due to market demand, and driven by huge profits, many criminals sink the net of evil into the deep sea. A destructive trawler is used, where all the creatures where the trawling is left, leaving only muddy white sand.
In order to protect red corals, China listed red corals as a national protected animal in 1988. In 2008, red corals were listed in an appendix to the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES), restricting their international trade. At present, China implements concession management for the import, export and trade of red coral, and there are only more than 200 handicraft shops licensed to operate red coral on the market.
Without these gorgeous lives floating on the ocean floor, this blue planet would just be a blue desert. Hopefully, when our children and grandchildren dive into the deep sea, they will be accompanied by corals.
Excerpt from: GIC