1. Basic structure of coral
Coral body consists of two layers of germ layers: the outer cell layer is called ectoderm; The cell layer inside is called endoderm. There is a thin mesothelium between endoderm and ectoderm, and there is no cell structure. This animal has no head and trunk, no nerve center, only a diffuse nervous system. When stimulated by the outside world, the whole animal body will react. Its lifestyle camp is free floating or fixed bottom habitat. Living corals live in the ocean.
The basic body shape of coral is cylindrical or disc-shaped, which is radially symmetrical, and the center of the body is the inner cavity. The intestine plays the role of digestion and absorption. There is a mouth above the lumen, and the gap between the lumen and the mouth is called the oral passage. There are tentacles around the mouth, stinging silk sacs in the tentacles, and stinging silk cells containing venom in the sacs, which are weapons for animals to defend and prey, which is why coelenterates are also called Echinotheca.
2. Classification of coelenterate corals.
There are about 9000 species of coelenterates, which are usually divided into 3 classes, namely, about 2700 species of hydra; There are only more than 200 kinds of Scyphozoa; There are more than 6 100 species of corals.
Coral is a general term for coelenterates. In daily life, what comes from seafood is called "coral", and what is "red" is called "red coral". Corals usually include soft corals, gorgonian corals, red corals, stony corals, horny corals, corals, light-colored corals and coral reefs. Some people mistakenly refer to the soft gill (Pennatula) and the colony anemone (Zoantharian) as "corals".
3. Ecological characteristics of stony coral
3. 1 According to the ecological environment and characteristics of stony corals (Table 2), they can be divided into reef-building corals. Non-reef-building corals (or deep-water stony corals) can be divided into two categories.
Deep-water stone coral, as the name suggests, lives in the deep sea. The record of the deepest known habitat is the symmetrical Aleutian coral found in the Aleutian Trench from 6296 to 6328 meters ... The deep-water stony corals are mainly single, few, small and monotonous in color. Trawls and dredgers can collect at different depths on the seabed.
Among stony corals, shallow-water stony corals are distributed in shallow waters, generally from the water surface to the water depth of 40m, and the distribution of individual species can reach 60m. Most of them are groups. It grows in tropical waters. When they live in the water, their colors are bright and colorful, which makes the tropical seashore dazzling, so the shallow coral area has the reputation of underwater garden.
Shallow coral grows in tropical or subtropical Indo-Pacific waters and Atlantic-Caribbean seas. However, due to geographical obstacles (the isthmus of Panama was formed 6 million years ago), the shallow coral in these two waters formed two completely different flora in the evolution process.
Facts have also proved that there are significant differences in the number and species of stony corals in the two sea areas. It is known that there are 86 genera and 1000 species (some people say there are 500 species and 800 species) in the Indo-Pacific flora, while there are 26 genera and 68 species (or 25 genera and 50 species) in the Atlantic-Caribbean flora.
The salinity of seawater for normal growth of shallow corals is 27 ~ 42 ‰, which requires clean water quality and hard substrate. In estuaries, it is not suitable for shallow coral growth, because continental runoff rushes into the sea, carrying a lot of terrigenous sediments. Therefore, it is futile to find shallow-water stone corals in the estuary.
4. Common families and genera of reef-building corals
The identification of reef-building corals is mainly based on their bone appearance, asexual reproduction mode, bone surface morphology, the number of development wheels of coral septa, the size of the septa and its attached decorative structure, and the presence or absence of axial columns. However, the classification order of modern living Lycopodiaceae and above is determined by the microstructure of bones (it needs slicing, grinding and microscopic examination). Therefore, the classification and evolution of higher-order elements in stony corals are the views of many scholars. In this paper, according to the morphological classification, zoogeography and paleontology of modern stony corals, Veron was used to modify Wells' six-radiant coral evolution system. It is known that there are 54 genera of 14 families 174 species of reef-building corals in China. Now only 4 families are introduced.
4. 1 branch of Pocilloporidag population of Cupertidae. The coral population is sheng-shaped or fused, and the diameter of coral cup is 0.5 ~ 2mm. The population is formed by outer tentacle buds, rarely exceeding the second septum, or even degenerating without septum. Needle-shaped shaft column or none. The common species are Colpora, Filariaceae and Vespora. There are cup-shaped corals in Hainan Island, which are small in size and less than 1mm in diameter, with undeveloped septa, or degenerated into spines, or none. The axial column is not or slightly convex, and the coral skeleton is solid, which is called "sea flower" in Hainan Island. Common species are antlers, antlers and antlers. Cup coral is not found in the coastal areas of Guangdong and Guangxi.
4.2 The outer tentacle buds of Cephalopoda of Cervidae form a massive, leaflike or branched population. Coral body is sheng-shaped, generally less than 2mm in diameter and sheathed. * * * There are thorns or grooves on the bone surface. Axle-free columns or axle columns are small and weak. The common species of this family are Acrop- ora, Montipora and As- treopora.
4.2. 1 Cervus, some branches are exactly the same, and a few short branches are blocky or shell-shaped. There is a large axial coral and many radial corals at the top of branches or branchlets. Radiation corals are tubular, nose-shaped, tube-nose-shaped, lip-shaped and semi-oblique-mouth tubular. This is one of the characteristics that distinguish species. Leaf sheaths are reticulate or pseudo-ribbed, without axial columns. This genus is the dominant genus in the Indo-Pacific flora, with the largest species and quantity, and the greatest change with the environment. For example, a. humilis, a rough antler coral, has a big shell at the bottom of the colony, and its branches are short and thick in a strong wind environment; In a stable environment with small waves, the branches are fully developed and the long bamboo shoots are tall and strong. Nereis elegans is the dominant species in Indo-Pacific region.
4.2.2 The rose population is massive, leaflike, multi-branched or shell-shaped. Coral cup is very small, the diameter is less than 1mm, there is no axis coral body, porous wall and no axis column. * * * Bone reticulation, shaped like various small vertical bone spurs. This genus is common in coral reefs, and Montipora digitata is the dominant species in the intertidal zone of reef platform. There are also common leaflike bodies, such as roses.
4.3 The Agaricus population of Corallinae consists of inner and outer tentacle buds, and the wall is a synaptic truss wall, with or without holes. The shaft column is composed of trabecula, round or long; Some are shaftless columns. The common genera of this family are Pavona and Pachyseris.
4.3. The colony of1Coral Peony consists of round and concave marginal buds. It is a horizontal plate, one-sided corrugated, shell-shaped, columnar or double-sided leafy group. The diaphragm forms a ridge, connected or unconnected by a synapse. Axial column protrudes from flat trabecular bone or does not exist. The common species in this genus are cruciferous, Grifola frondosa and mutant flowers.
4.3.2 Phyllostachys pubescens is leaflike or unplanned, and the ridge formed by the coral ridge of leaflike species is long and parallel to the edge; Large-scale groups have different ridge lengths. P.rugosa, this is a common coral.
4.4 The colonies or monomers of the fungus family of Corallinaceae have attached stalks in the larval stage and live freely in the adult stage, which are disc-shaped or rectangular. Group single or multi-port roads. Close the truss wall. There are many septa, which are transparent in larval stage. Coral ribs have thorns continuously or intermittently. Small beams and columns or underdeveloped. The type of septate and backstab is an important feature of species fixation. The common genera of this family are fungi, Pteris rotundifolia, Pteridophyta, Pteridophyta, Herpolitha, Halomitra, Sandalolitha and Podabacia. Coral genus in Shi Zhi is single, disc-shaped or oval, flat or convex, which varies with the living environment of larvae. Adults have holes in their body walls. Most coral ribs degenerated into backstab, and the diaphragm was nonporous. Diaphragm edge teeth and backstab are important features of classification. Life is mostly yellow, and a few edges have a circle of rose red. Common fungi are Fusarium, Fusarium echinosporium and so on.
5. Reef-building corals are endangered animals in the ocean.
Appendices 1 and 2 of the Convention on International Trade in Endangered Species of Wild Fauna and Flora clearly point out that all species of Quercus belong to the second-class endangered wild animals. 1997 is the international year of coral reefs, calling on all mankind to protect coral reefs that are on the verge of serious degradation. The destruction of coral reefs is becoming more and more serious, turning the oasis in the blue desert into a real desert. According to "1997 Global Coral Reef Survey", coral reefs around the world are generally destroyed, 95% of which are caused by human factors. They called for saving coral reefs. Restoring the ecosystem destroyed by coral reefs has become a hot spot of concern, because the backbone (or framework) of modern coral reefs is reef-building corals, and the first thing to bear is the death of reef-building corals. The restoration of coral reef ecosystem means the vigorous development and growth of reef-building coral communities. Therefore, for the sake of mankind and future generations, we should consciously care for nature and protect the species that make reef corals. It is strictly forbidden to buy and sell, and through the legislation of governments at all levels, efforts are made to protect reef-building corals, so that reef-building corals will continue to develop and create greater productivity for human beings to continuously use.
Zou, bulletin of biology, vol.33, No.6, 1998, pp.8 ~11.
Coral is composed of calcareous shells secreted by coelenterates in the ocean. This coelenterate is called coral. Coral is shaped like a branch, and its chemical composition is calcium carbonate, which is opaque or slightly transparent, fine in texture and oily. Coral is produced in warm marine areas, and there are two main producing areas: one is from Japan to Taiwan Province Province; One is the Mediterranean coast. Coral hardness is similar to lapis lazuli, and it is fragile and easy to break. It has red, pink, white and black colors, with red as the top grade and red coral as red as fire, which was called "fire tree" in ancient times. Most red corals live in the deep sea below 100 meters. It is found in the waters near Taiwan Province Province and Xiamen, China, with pink body color and small limbs. The world-famous red coral is found in the Mediterranean and Atlantic oceans. Red coral is mainly used in jewelry products (making necklaces. Rings or pins, etc. ), used for carving figures, flowers and other handicrafts. At present, the red coral seen in China market is mainly imported from Japan, which is in short supply and expensive.
Corals live in warm seas, crowded and fixed on rocks.
New corals grow on dead coral skeletons, and some grow into dendritic structures with slender and flexible branches. Coral is beautiful in shape: it has antlers; There are trumpet-shaped tubular corals; There are many kinds of Shi Zhi corals such as mushrooms. Colors are orange, pink, light green, purple, blue and white ... colorful. According to the number of tentacles, corals can be divided into two types-eight corals and six corals. Coral tentacles are very small, and they all grow beside the mouth. The "belly" (inner cavity) is divided into several small rooms (digestive cavity), through which seawater brings food into the digestive cavity for absorption. Living corals have the ability to absorb calcium and make bones.
Living corals die, new corals keep growing, and over time, the calcareous bones of dead corals form coral reefs and coral islands.
Jade is pure, and a gentleman is beautiful.
2, Jinyutang jewelry, with your happiness and well-being.
3. Jinyutang-the paradise you believe in.