Coral is an amazing sea stone. Are corals an animal or a plant? Where are corals found in nature? What are corals
Meet this coral
Almost all of us have seen corals in a photo, video or even live, and we know their appearance. But really, let's find out.
Corals are a whole bright underwater world)
What are corals? Definition
First, let's define, not plants and not just a fancy stone, but living sea creatures that have a special structure of a limestone skeleton that grows every year by about 15 mm, they are also called polyps. These animals are the lowest intestinal-cavity multicellular creatures in the world's oceans.
(The structure of the coral)
What are corals? Structure
Imagine a solid calcareous cylinder lined on the inside and outside with a soft tissue of cells. In the center of the cylinder is the "mouth" of the coral and then it passes into the intestinal sac, or rather the intestinal cavity. The coral feeds on marine plankton, trapping small marine organisms with its tentacles around the mouth, the tentacles have mucus on them that paralyzes the victim, and he puts them in the center and lowers them inside the animal, so he feeds. This whole living organism is attached on a solid sole to the stones on the seabed, with its help, the coral can move.
(Coral in section)
What are corals? Varieties
Corals are very different in their structure; they are divided into eight-ray and six-ray corals according to the number of tentacles. There are also corals practically without a hard skeleton, called soft, or with a hard skeleton, which are called madrepore, there are even mixed types, for example, Tube coral. Corals can also be solitary or colonial, which together form entire barrier, coastal reefs or atolls, which means entire coral islands. Old corals die off, leaving behind a skeleton and a new living coral grows on top of them, so gigantic fantastic structures grow year after year, which in terms of brightness of colors can compete with the brightest creatures in the world.
What are corals? Peculiarities
Marine corals have amazing features. For example, they, like plants, are capable of photosynthesis: take energy from light, water and carbon dioxide. This is due to the single-celled algae that lives in their tissues. This is a kind of symbiosis in wildlife. During the day, the coral functions just like a plant, and at night it lives the life of an animal. Another amazing feature lies in the ability of almost every coral to glow when exposed to ultraviolet rays or blue light.
(What are corals? Corals are God's unique creation)
What are corals? reproduction
Coral reproduces in an amazing way, even in two ways. Once a year there comes a time when corals release their sex cells into the water, which fill the ocean in huge numbers, many of them are washed ashore, fish will feast on many of them, but some of the cells will meet each other and form a living organism, which for the first time time floats in the water, and then attaches itself to the bottom. Another method is called budding, a coral tongue is pulled out from the mother coral and a new coral is formed on it, this is how a whole colony is formed.
(Coral breeding)
What are corals? Outcome
Now you know a little more about what corals are. These are amazing beautiful living organisms, unlike anyone else, which were created by an intelligent Creator who creates beautiful and perfect.
Coral(from the Greek "koralion" - the son of the sea). For a long time, scientists found it difficult to determine the class to which corals can be attributed. The ancient Greek philosopher and botanist Theophrastus considered it to be something between a stone and a plant, the Roman naturalist Pliny the Elder described its properties in a book about marine animals and medicinal drugs that are made from coral, and the Swedish naturalist Carl Linnaeus identified the mineral as a separate category of zoophytes, then eat animal plants.
And only at the end of the XVIII century. scientists came to the conclusion that corals are the outer skeleton of polyps - invertebrate organisms that live in the sea. Tree-like branches are formed as a result of the release of a specific calcareous substance by polyps. The length of the coral outgrowths reaches 40 cm, the thickness does not exceed 4 cm. The raw material for large ornaments is the branching of corals, where significant thickenings can be seen. 85% corals are composed of solid calcite, the remaining 15% is magnesium carbonate, iron and manganese oxides, organic compounds
Physical and chemical properties of coral
- Color - white, red, pink, less often yellow, black, blue.
- Glitter - waxy.
- Transparency - opaque.
- The syngony is amorphous.
- Hardness - 3.5-4 on the Mohs scale.
- Density - 1.3-2.6 g per cm3.
- Fracture - splintery.
Story
The Roman poet Ovid in his Metamorphoses associated the appearance of coral with the victory of Perseus over the Gorgon Medusa. When Perseus flew over the seas, holding the head of a defeated monster in his hands, drops of blood fell from it and turned into red coral branches. Ancient coral products were found on the territory of the Sumerian kingdom, located once in Mesopotamia. The age of the finds, according to experts, is at least 6,000 years. Corals themselves are considered representatives of one of the first groups of organisms on earth and have existed on the planet for more than 500 million years.
Since ancient times, the mineral has been popular among the servants of a religious cult. Medieval priests considered it a reliable protection against the machinations of the devil, a talisman of wisdom and an amulet from worldly temptations. Rosaries were made from corals, crosses and other items of church use were inlaid with them.
In Rus', small balls were cut out of the mineral - kinglets, the purpose of which is still a mystery to archaeologists, but they are regularly found in Slavic burials. For example, 15 coral balls were found in the grave of Boris Godunov.
How and where are they mined
Coral mining is carried out in the waters of Japan, Australia, Taiwan, the Canary Islands, as well as in the Red and Mediterranean Seas.The depth of growth of polyps is from 3 to 300 cm. From that time to the present day, corals are mainly mined using two long wooden beams, to which a load and several nets are attached. From the boat, tackle is lowered into the water, and they are dragged along the bottom. Broken corals get tangled in the nets, after which the beams are raised. Since this method causes significant harm to marine fauna, divers began to be sent for corals. However, this did not bring any practical benefit - people treated the reefs in no way more accurately. In the Hawaiian Islands, small submarines are used for coral mining.
How to distinguish from a fake
Considering that the cost of producing artificial corals is about seven times lower than the price of natural ones, the nature of origin must be approached very carefully. Outwardly, it is quite difficult to distinguish an imitation, because it has a natural color and physical properties similar to the original.
A distinctive feature of natural corals is a characteristic mesh pattern. On a fake mineral, it, respectively, is not.
Price.
The cost of products with corals depends on the color and quality of the mineral. The most valuable are pink and red noble corals.A silver ring with a small mineral insert can be purchased for $34-60, while a pendant made of high-quality richly colored coral will cost $250-300. However, a good 10 carat cabochon costs $250 or more. It is impossible to say that coral is expensive, nevertheless, good samples in the form of jewelry inserts or beads are by no means cheap.
coral varieties
Corals are divided into noble, root and foamy. The root is called a variety, which is a coral bush. Minerals that form the transition from the legs to the solid part of the massif are referred to as foamy. These species are inexpensive and have a wide variety of shades. Noble corals are used in the jewelry industry, have different trade names depending on the color. So, the black mineral is called akkabar, white - bianco, pale pink - pellet d "angelo (angel skin), pale pink - rose pallido, rich pink - rose vivo, pinkish-orange - secondo coloro, red - rosso, dark red - rosso scuro, cherry - arciscuro carbonetto (bull's blood).
Processing and use
Natural corals have a matte surface, and a glassy sheen is obtained by grinding with fine sandpaper and polishing with felt. Minerals of low quality with cracks and large pores are ennobled before processing - impregnated with colored wax.In products, corals are used in the form of round beads, cabochons and twigs. The white-colored mineral is not popular with jewelers.
Looking at corals and, few people would think that they are almost identical in chemical composition. Both minerals consist mainly of carbonic lime.
The porous structure of corals exactly matches the structure of human bone. Blood vessels easily grow into them, and over time, it becomes impossible to isolate the coral from the original bone tissues.
Even Charles Darwin in his writings mentioned the painful sensations that corals can cause. Indeed, some of their species cause severe burns. Corals growing in the Caribbean and Red Seas are especially dangerous.
If you had a chance to dive into the depths of the sea, then you probably saw bright corals of bizarre shapes there. They look like living beautiful bushes with numerous branches that you will not find in an ordinary garden.
Are corals an animal or a plant? This thought comes first when faced with this maritime miracle. For a long time, scientists could not figure out what kind of organisms corals belong to. Only in 1982 did a French researcher prove that these were not marine plants.
coral base
They are made up of very small organisms called polyps. This is a class of intestinal invertebrates that can live both in colonies and alone. To date, there are approximately 6,000 species.
These multicellular organisms have appeared since the ancient mammoths. They have only one cavity - the intestines, through which food is digested. Hence their name follows - intestinal. Therefore, there is no dispute about whether corals are an animal or a plant. Polyps can have different sizes - from a millimeter to several centimeters.
There are also huge ones - from half a meter in diameter. These include representatives of the madrepore species. From numerous polyps, one large organism emerges, which resembles a huge bush that attracts the eyes of divers.
The structure of the polyp and nutrition
It is quite primitive and resembles a cylinder with tentacles. Some polyps have a skeleton that is made up of calcium. Not all polyps can move along the seabed. Only their tentacles bend, helping to get food. How does this happen? Coral tentacles pull small fish and shrimp into their nets.
In the intestinal cavity, the polyp has cilia that create a water flow. Thanks to him, oxygen and food enter the body. We hope we have answered the question of whether corals are an animal or a plant.
Dimensions and shape
The rich variety of a wonderful living organism knows no limit. The smallest coral reefs can be a few centimeters long, the largest reach over 5 meters in height! Their shape can be very diverse: in the form of a twig, a curved hook, a barrel, a feather, or even in the form of a household item.
There are also more complex corals, resembling a fan, a bird, an animal. Some colonies grow up, others in breadth. They often look like spread out colorful carpets. What are corals? Their colors are the most diverse - these are shades of red, black, pink, green tones. Blue and purple corals are quite rare.
Features of coral polyps are such that they are found only in tropical and subtropical waters. Some species live in the polar seas in the north. For example, hersemia. Another noteworthy thing is that all corals live mainly in salty clear waters.
Many coral species prefer to live at shallow depths that are well illuminated by daylight. This is due to the fact that this living organism lives in partnership with algae, which need light for photosynthesis. What types of corals are there? The most famous are porous, mushroom-shaped, black. There are about 400 species of corals in the Great Barrier Reef alone!
deep polyps
These include curved corals called "batipates". They can be found at a depth of over 8000 meters! Colonies appear only at the bottom of a solid substance. Also excellent habitats for them are sunken ships, aircraft, underwater structures.
Deep sea corals prefer a sedentary lifestyle. Some of them can move along the seabed, but very slowly. Despite the fact that the structure of corals is primitive, they have complex biological rhythms.
Most often, this unusual organism behaves actively at night. Corals throw out their tentacles like nets and wait for food. As dawn breaks, the polyps shrink and prefer to be at rest.
coral breeding
Scientists believe that this marine organism can reproduce both vegetatively and sexually. Amazing ability, isn't it? Vegetative consists in fragmentation, and then separation of the "child" from the parent polyp.
Usually, a small “plate” is formed on the coral’s stem, which then detaches and takes root on the bottom of the sea soil. The sexual method suggests that the corals must be male and female. This is not the case for all polyps. Reproduction in this case occurs as follows: during fertilization, sperm enter the gastric cavity. Then they go outside and find themselves in the area of \u200b\u200bthe mouth of the female polyp.
Cell division occurs traditionally. As a result of embryonic development, small larvae are formed, which then swim freely in the water. Such information should dispel the doubts of those people who have not yet found a clear answer to the question of whether corals are an animal or a plant.
A little about the benefits
Corals delight the eye with their unusual appearance, but this is not their only advantage. In fact, they are the builders of the marine ecosystem. And they organize it without too much fuss. Forming colonies, they provide a roof over their heads to various marine inhabitants, such as: eels, rays, starfish and various fish.
Jewelers claim that marine polyps are an excellent material for the manufacture of various products. It is known that in ancient times, coral necklaces were hung around the neck of small children for better teeth growth. It was also believed that sea gifts help in difficult situations. Therefore, they were used as an amulet that could protect from the evil eye and give strength in difficult situations. Traditional healers believe that corals regulate metabolism, have a beneficial effect on the cardiovascular system, and improve memory.
In conclusion, I would like to note that corals belong to the animal world and you can tell a lot of interesting things about them.
In the depths of the warmest seas
There are beautiful trees
Pale pink most tender,
Blue and white links.
Greek legend says that the coral came from the blood of the Gorgon Medusa after she was beheaded by Perseus. In Rus', it was believed that the coral is stored in the dragon's brain, so another name for this stone is dragonite.
At its core, coral is an organogenic mineral consisting of calcite with an admixture of magnesium carbonate and aragonite. It represents the external skeletons of modern invertebrate marine animals. Corals belong to the class Cnidaria, or cnidarians, which unites about 10 thousand species. Over 2,500 varieties of corals are known in nature, up to 350 of their color shades are distinguished. For the manufacture of jewelry, only 5 types are processed and used.
Considered very rare blue and blue corals - akori
,
And black - akabar.
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White stony corals(the old trade name is “bianco”) are not often used in jewelry.
Red- the most common. Known, beloved are "Sardena", and rich red Japanese "Moro-corals"
pink corals stand somewhat apart. Their delicate color is valued by true connoisseurs along with scarlet. The French call these light, almost creamy shades "peau d'ange" - "angel skin".
Medicinal properties. In the countries of the East, folk healers often use white coral powder for better fusion of bones in case of fractures, in dental prosthetics. Traditional healers of almost all countries believe that coral is an excellent tool for improving tone and relieving fatigue. It improves memory, has a beneficial effect on hearing and vision, protects against nervous breakdowns in stressful situations. Phytotherapists believe that corals can improve blood circulation and positively affect the functioning of the cardiovascular system. Pink corals are useful for insomnia, have a sedative effect on the nervous system. It is believed that coral beads can relieve headaches (in Portugal) and help with throat diseases (in England).At all times, coral has been a happy stone that gives a positive charge to its owner.
magical properties. “The people of India value corals as highly as pearls. Their priests and soothsayers even ascribe something sacred to corals, claiming that they have the power to protect those who carry corals with them from dangers ”(Pliny the Elder“ Natural History ”).
Celtic warriors of prehistoric times decorated their weapons and shields with red corals. In Itilia, coral beads are one of the first ornaments for girls. They protect them from the evil eye and troubles, especially if their favorite amulet resembles a human figure - cornetti. The Neapolitan king Ferdinand always carried a sprig of coral with him and directed it at everyone who, in his opinion, could have an “evil eye.” Mexican Indians still claim that wearing coral beads drives away evil spirits from a person.
Corals - talismans of travelers. It is believed that during trips, the mineral protects its owner from possible violence and keeps from natural disasters: floods, storms, fires, storms.
Returning from vacation, many bring home souvenirs that will remind you of the sandy beach and the warm sea. Often among them you can find corals. They attract attention with their bizarre appearance, and they are specially mined for the manufacture of souvenirs. And what are corals: plants or animals?
coral reef
At first glance, it may seem that corals are plants that grow in coastal areas and in shallow waters in warm seas. But in fact, corals are the skeleton of a colony of living organisms called coral polyps.
Coral polyps belong to the class of marine invertebrates. Many species of coral polyps live at the bottom in large colonies that form coral reefs of extraordinary beauty. The diversity of coral polyps is more than 6,000 species that live mainly in warm waters, although individual specimens also live in northern latitudes. Colonies of coral polyps have been found in the North Atlantic, off the coast of Scotland and even in the rather cool White Sea.
The structure of the coral polyp
Coral polyps reproduce by budding and also by sexual reproduction. The resulting larvae swim for some time in the thickness as zooplankton, and then settle to the bottom, where they spend the rest of their lives. Corals feed, as a rule, on plankton, absorbing it along with sea water during the filtration process. But some species are able to absorb small crustaceans or even fish. The skeleton of corals can be not only calcareous, but also consist of protein compounds. And there are corals that are generally devoid of any skeleton.
Brain coral from the order of stony coral polyps
All coral polyps are divided into two subclasses: six-ray (in which there are 6 orders) and eight-ray (in which there are 5 orders). The most numerous order is stony corals, which includes more than 3,000 species. Representatives of this order are most often found among the inhabitants of coral reefs and in souvenir shops. But other units are no less interesting.
Sea anemones - representatives of six-beam corals of the sea anemone order 
Members of the Zoantaria
And this coral polyp from the detachment of sea feathers
Corals are often used not only for making souvenirs, but also in jewelry. For this reason, corals are prohibited from exporting from some countries, such as Turkey, Egypt, Thailand. You can export corals if you have a receipt proving their purchase in the store. But in all other cases, frivolous tourists can expect trouble at customs.
