Corals are the largest of the coelenterate phylum Anthozoa, the largest of the coelenterate phylum, with more than 7,000 species, all of which are marine products. Polyps are further divided into eight-ample coral suborders and six-ample coral subclasses. Depending on the skeletal texture and body size of the hydra, corals are generally divided into several types, such as large polyp scleractinian (LPS), small polyp scleractinian (SPS), soft coral, and anemone.
There are benefits at the end of the article!
The chemical composition of coral is mainly CaCO3 (calcium carbonate), in the form of microcrystalline calcite aggregates, there is a certain amount of organic matter in the composition, the form is mostly dendritic, there are longitudinal stripes on it, each monomer coral cross-section has concentric circles and radial stripes, the color is often white, there are also a small amount of blue and black, coral not only image like branches, bright and beautiful color, can be used as ornaments, and has a high medicinal value, but relative to the medicinal value of its role in the environment is irreplaceable.
Coral reef ecosystems, also known as underwater "tropical rainforests", have important functions such as protecting the coast, maintaining biodiversity, maintaining fishery resources, and attracting tourism. Many coral individuals are colorful, the brilliant color is not inferior to the various flowers on the land, some coral varieties have a stunning fluorescent effect, and different types of corals can build a coral reef ecosystem in the aquarium, making corals extremely competitive in the aquarium industry.
Coral Chase Documentary (1)
Persian scientific name
Persian: xuruhak
Morphological characteristics
Coral image like branches, bright and beautiful colors, can be used as decorations. Gem-quality corals are red, pink, and orange-red. Red is formed due to corals absorbing about 1% of iron oxide from seawater during growth, and black is due to the presence of organic matter. Has a glassy to waxy luster and opaque to translucent.
Growing environment
It grows in tropical and subtropical regions with temperatures above 20 °C and its vicinity, in calm and clear rocks, platforms, slopes and cliff faces, and crevices with a water depth of 100-200 meters. It is mainly produced in the Mediterranean Sea.
Distribution range
It is distributed in tropical and subtropical regions with temperatures above 20 °C at the equator and its vicinity.
Propagation methods
Corals can reproduce sexually or asexual reproduction. The sexual reproduction of corals has the advantages of strong fertility, high genetic diversity and no damage to the mother coral. The eggs and sperm of the polyps are produced by the reproductive glands on the diaphragm and are discharged into the sea through the mouth. Fertilization usually occurs in seawater and sometimes in the stomach circulating lumen. Usually fertilization occurs only between eggs and sperm from different individuals. The fertilized egg develops into a floating wave larvae covered with cilia that can swim. After a few days to a few weeks, it solidifies on the surface of the solid and develops into a hydra. It can also reproduce in the form of buds, and the buds are not separated from the original hydra after formation. New shoots continue to form and grow, and then multiply into groups. When the new hydra body grows and develops, the old hydra body below it dies, but the bones remain on the colony. Soft corals, gorgonian corals and blue corals live in groups.
Basic structure
Corals are marine invertebrates of the Genus Anthozoa. The body of the coral is composed of 2 germ layers: the cell layer located on the outside is called the ectoderm, and the inner cell layer is called the endoderm. There is a thin, no-cell structured mesocoagle layer between the inner and outer germ layers. Such animals have no head and trunk, no nerve center, only a diffuse nervous system. When stimulated by the outside world, the entire animal body responds. Its lifestyle is free-floating or fixed to the underlying habitat. Living corals, living in the ocean.
Species classification
Corals typically include soft corals, gorgonian corals, red corals, stony corals, horned corals, hydra corals, flies and sheng corals.
Species division
Corals (Anthozoa)
Corals are the largest of the coelenterate phylum, all seafood. All are hydra-type monomers or group animals, and there are no jellyfish-type generations in their life history. The structure of the hydra of the coral order is more complex than that of the hydra, and the body is two-radiant symmetry. Common species such as coralliumrubrum, metridium, and sea cactus (Cavernularia).
There are about 9000 species in the known coelenterate phylum, usually divided into 3 orders, namely Hydrozoa , about 2700 species; Scyphozoa , which has only more than 200 species; and Anthozoa ( Anthozoa ) , which has more than 6100 species.
Coral is a general term in coelenterates, in daily life, where the shape is peculiar, exquisite and transparent and comes from seafood, people are crowned "coral (coral)", where "red", collectively known as "red coral". Corals typically include soft corals, gorgonian corals, red corals, stony corals, horned corals, hydra corals, flies and sheng corals. Some people mistakenly refer to the soft-bodied sea gills (Pennatulacea) and the herd of sea anemones (Zoantharian) as "corals".
There are about 1,000 species of stony corals (Madreporaria or Scleractinia); about 100 species of black and spiny corals (Antipatharia); about 1,200 species of gorgonians (or horned corals, Gorgonacea); and only one species of blue corals (Coenothecalia) remains.
Stony corals are the most well-known and widely distributed species, living in individuals or groups. As with black and thorn corals, the number of diaphragms is a multiple of 6 or 6, and the tentacles are simple and not feathery
Black and spiny corals are whip-shaped, pinnate, tree-like or bottle-brushed and found in the Mediterranean, West Indies and the coastal waters of Panama.
Due to environmental pollution, a component of the air that makes corals perishable appears in some coral areas, so the global coral species and numbers have decreased dramatically.
Ecological division
According to the ecological environment and characteristics of the growth of stony corals, it can be divided into two categories: reef-building stony corals and non-reef-building stony corals (or deep-water stony corals).
Among the stony corals are deep-water stony corals, which, as the name suggests, inhabit the deep sea. The deepest known habitat record is the discovery of the Fungiacyathus symmetricusaleuticus at 6296-6328m in the Aleutian Trench. Deep-water stone corals are generally monomeric, minority groups, and individuals are small and monotonous in color. It can be collected at different depths of the ocean seabed with trawls and mud miners.
Shallow water stony corals in stony corals are distributed in shallow water areas, generally from the surface layer to a water depth of 40 m, and individual species can be distributed up to 60 m deep. The vast majority are groups. It thrives in tropical seas. When they live in the water, they are brightly colored and colorful, and the tropical seashore is dazzling, so the shallow stone coral area has the reputation of an underwater garden.
Shallow stony corals grow in tropical or subtropical in the Indo-Pacific waters and the Atlantic-Caribbean. But due to geographical barriers (the Isthmus of Panama was formed 6 million years ago), shallow stony corals in these two sea regions have evolved into two distinct communities.
The facts have also proved that there are significant differences in both number and species of stony corals in the two sea areas. The Indo-Pacific fauna has more than 1,000 species in 86 genera (some say 500 species and 800 species), while the Atlantic-Caribbean fauna has 68 species in 26 genera (or more than 50 species in 25 genera).
The normal growth of shallow stony corals is 27 to 42 ‰ of seawater salinity, and it requires clean water quality and hard substrate. In the estuary, because continental runoff rushes into the sea and carries a large amount of land-based sedimentary material, it is not suitable for shallow stone corals to grow. Therefore, it is futile to look for shallow stony corals in the estuary.
Coral bleaching is the phenomenon of coral whitening. Under normal circumstances, corals appear in a variety of different colors such as green, blue, yellow, brown, red, and purple, but these colors are not owned by the coral itself, but come from the symbiotic algae (zooxanthellae) in the coral. Corals rely on micro-symbiotic seaweeds in their bodies to survive, and seaweeds provide energy to corals through photosynthesis. If the symbiotic algae leaves or dies, the corals turn white and eventually die from the loss of their nutrient supply. Symbiotic algae is a dinoflagellate that is densely distributed in cells in the coral endothelial layer under normal coral physiology.
It is estimated that per square centimeter of coral tissue may contain 50 to 5 million symbiotic algal cells (0.5 to 5× 10cells/cm2), because the symbiotic algae contains a variety of pigments, so that the corals appear various colors. The symbiosis of symbiotic algae and coral is a kind of coexistence and co-prosperity relationship, symbiotic algae on the nutrition, metabolism and growth of corals, but when corals suffer from the pressure of drastic changes in the environment, this delicate symbiotic relationship may be disintegrated, and corals will lose symbiotic algae or photosynthetic pigments and become white, which is the so-called "bleaching".
Coral reefs are among the most productive, biomass and biodiverse ecosystems on Earth, and because of these properties, coral reefs are also known as "rainforests in the ocean". These features are maintained in the delicate symbiotic relationship between corals and symbiotic algae, and coral bleaching destroys this symbiotic relationship, causing the entire coral reef ecosystem to disintegrate, not only making the coral reef lose its charm, but also making the coral reef building and water and soil conservation function lost. In recent years, coral bleaching incidents around the world have been frequently reported, which not only reflects the warning signs of global environmental changes, but also shows the signs of the gradual destruction of the marine ecological environment.
So can corals recover after bleaching?
Albinism ≠ death.
Due to the lack of scientific popularization, or most of the articles reporting the decline of coral reefs themselves mix bleaching and death but lack explanations, many people may think that coral bleaching is coral death. This is not the case.
Coral bleaching refers to coral bleaching, which refers to the coral loss of symbiotic zooxanthellae in coral cells due to various factors (such as high temperature, low temperature, high light, etc.), which passes through the transparent tissue layer and shows the color of the bones in it (most of the coral bones are white). If these stressors are not removed, the coral will be in a state of bleaching for a long time, which will lead to coral death.
Here I also add a picture of the same coral to make you more aware of coral bleaching:
At this point, you may be able to notice the difference between coral bleaching and coral death, and you can also find the answer.
Well, coral bleaching is not serious – of course not.
Coral bleaching → √ coral debilitation
Coral bleaching + prolonged exposure to environmental stress → coral death (irreversible) √
Undead bleached corals + suitable conditions → corals may recover √
First, we identified two major sources of energy for coral growth — zooxanthellae photosynthesis and plankton caught by polyps reaching out with spiny tentacles.
See the short yellow-brown tentacles of the antlered polyps in the picture. This is a powerful weapon used by corals to catch plankton in the sea. And this energy source is also a guarantee that there is a possibility of recovery after coral bleaching.
Why do I say "coral may recover" instead of "coral recovery."" That's because it's not clear how long corals are destined to die if they are bleached, or how long it will take for corals to reabsorb to regain their former glory. It is also because coral researchers are still working on the appropriate conditions that give corals the possibility of recovery.
Summed up in one sentence – coral bleaching is a possibility of recovery.
Coral ecosystems are the only symbiotic system of flora and fauna on Earth. Coral reefs with their complex shapes and skeletons form a variety of living places, providing a good living environment for other organisms, because the coral reef environment is stable and the water body is sufficient, so it forms a special ecosystem that is different from the surrounding marine environment. So what are the most likely symbiotes to see around coral reefs?
1, anemones: sea anemones are fixed on the seabed, they will use the poisonous barbs on the tentacles to catch small fish and shrimp, anemone friends are really pitiful. But they have a very harmonious symbiotic relationship with clownfish.
Clownfish are immune to the toxicity of sea anemones, so they can safely hide in the tentacles of the anemones and eat the parasites in them to protect the anemones.
2, giant clams (giant clams): As the largest mollusks on the earth, giant clams are one of the most important inhabitants of coral reefs, and they can ensure the health of coral reefs. The picture shows giant clams in Komodo National Park in Indonesia.
Giant clams are filters in the ocean that reduce harmful nutrients in the seawater and provide food for other organisms. Giant clams themselves are part of the hard calcium carbonate structure of coral reefs. The picture shows the giant clam photographed by National Geographic.
3, sea urchins: sea urchins are covered with long and pointed body spines, which are sometimes poisonous. It should be said that the defense ability of sea urchins is one of the best in marine life. But the biggest problem with sea urchins is that they are difficult to move. So they move with the help of crabs.
Sometimes sea urchins have to fight a fierce battle if they want to climb on crabs. In the end, the combination of crab and sea urchin was in action: when the crab was running rampant, the sea urchin lay on it and hitched a ride.
4, chocolate chip sea star (chocolate chip sea star) is a little sad to say, although it is called chocolate chip starfish, but it has nothing to do with desserts. This starfish is able to protect other species, but in return.
Reply keyword: Chase coral