Starfish (Echinoderma, starfish)
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[hǎi xīng]
Starfish is a kind of invertebrate, not a fish. The body is flat, star-shaped and wrist-shaped, and there are10,800 species, which are found in various oceans, with the most species in the northern Pacific Ocean. Radial diameter 1? 65 cm, mostly 20? 30 centimeters. The wrist is hollow and covered with short spines and forked spines. There are rows of tube feet (some with suction cups at the end) in the ditch below, so that starfish can crawl in any direction, even climb a steep surface. Lower starfish feed on food grains along the entrance of wrist groove. Higher kinds of stomachs can be turned over to the bait for in vitro digestion or swallowed whole. The endoskeleton consists of a calcareous bone plate. Breathe through the skin. There is a bright spot on the wrist. Most of them are hermaphroditic and a few are hermaphroditic; Some can reproduce asexually.
Chinese scientific name starfish
Animal kingdom
Echinodermata (Echinodermata)
Class starfish (Asteroidea)
Animal race
Distribution areas are mainly distributed in shallow seabed sandy land or reefs all over the world.
English name starfish
catalogue
1 Introduction
2 classification
Banding order
Acanthoptera
Forceps
3 Distribution area
4 Appearance characteristics
pathological/bodily sign
Body wall and bone
eye
spine
5 internal structure
Water pipe system
respiratory system
digestive system
nervous system
6 predation
Predation process
Predator
7 environmental value
8 medicinal value
9 Special functions
Starfish are covered with "monitors"
Regenerative ability
10 hazard control
Main hazards
Prevention and cure method
1 1 Reproduction
1 Introduction
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Starfish are mainly distributed in shallow seabed sand or rocks all over the world, and mainly feed on plankton. We know little about its ecology. From its appearance and slow movement, it is hard to imagine that starfish is a carnivore, and it also plays an extraordinary and important role in marine ecosystem and biological evolution. This is why it is widely distributed in the world. About 1800 species of starfish live in all the oceans in the world, such as the Atlantic Ocean, the Pacific Ocean, India, the Arctic and the Southern Ocean. Starfish occur in a wide range of depths from the intertidal zone to the deep sea (about 6000 meters deep).
Starfish is one of the animals that can regenerate rapidly. If one of the tentacles of a starfish is cut off, it will grow back in a short period of time, and the tentacles cut by a few starfish will grow into a starfish, which has the characteristics of earthworms, lizards, lobsters, polyps, snails and the most regenerative worms.
2 classification
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Banding order
Yellow starfish
The species of Phanerozonia have obvious marginal plates, sucker at the foot of the tube, and may have no anus. Including most deep-sea species, such as Albatrossaster richardi, which is found at a depth of 6,035 meters (19,800 feet). The radial diameter of the mud starfish (Ctenodiscus crispatus) is about10cm, the wrist is short and blunt, the body plate is wide and yellow, and it is abundant in the mud bottom along the northern coast. Northern genera such as Astropecten, Psilaster and Luidia with long and sharp wrists and spines at the edges. The genus Linckia, which is mostly found in the Indian Ocean-Pacific Ocean, can grow into a new individual from a small wrist.
Acanthoptera
Sun starfish
There are Spinulosa with clusters of spines, and there are suction cups at the foot of the tube, but forked spines are rare. Asterina gibbosa is a common camel petrel in the rocky seabed of Europe. In the north, the genera Crossaster and Solaster have many short wrists and wide body plates. Crossaster papposus has 15 wrists. Forcipulata has two-valved forked spines with long stalks, which can protect or feed. Common species that feed on bivalves in shallow water include Asterias rubens distributed in northern Europe and A. amurensis from Bering Sea to Korean Peninsula. Pisaster brevispinus on the west coast of North America is 65 cm (26 inches) long and is one of the largest starfish in the world, feeding on sand money sea urchins and so on. The multi-wrist sunflower starfish (Pycnopodia helianthoides) from Alaska to California has15 ~ 24 wrists. Heliaster in China and America have up to 50 wrists.
Forceps
starfish
The marginal plate of Forcipulata is not obvious, and the forked spines are complex and sheared, such as Asterias, Pterasteridae and Stephanasterias. [ 1]
3 Distribution area
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Starfish are distributed in all the seas of the world, with the most species in the North Pacific region. Vertical distribution from intertidal zone to water depth of 6000 meters. Magnetic starfish is a deep-sea animal, and its habitat depth is not less than 1000 meters. Starfish live in all kinds of sediments, but it is rare on the soft mud bottom. The genus Nauclea is not strict with the bottom material, and often moves with the number of bivalves it eats.
4 Appearance characteristics
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pathological/bodily sign
Starfish, sea cucumber and sea urchin are echinoderms. They usually have five wrists, but there are also four or six, and their bodies are flat and mostly star-shaped. The whole body consists of a lot of calcium.
starfish
Bone plate is combined by connective tissue, and there are prominent spines, tumors or warts on the body surface. Some have as many as 50 wrists, and there are 4 rows of dense tube feet under these wrists. Using tube feet can not only catch prey, but also allow yourself to climb on the rocks. The big starfish has thousands of tube feet. Starfish's mouth is in the middle of its lower body, which can be in direct contact with the surface of the object that starfish has climbed. Starfish vary in size, from 2.5 cm to 90 cm, and their body colors are different. Almost every one is different. The most common colors are orange, red, purple, yellow and cyan.
Body wall and bone
The body wall of echinoderms consists of epidermis and dermis. The top surface of the body wall is a thin stratum corneum, and there is a layer of single ciliated columnar epithelial cells in it. The epithelial cells are mixed with nerve sensory cells and mucous gland cells, and the secretion of gland cells can adhere to the sediment falling on the body surface and then be swept away by cilia. Below the epidermis is a layer of nerve cells and fibers, which constitute the subcutaneous nerve plexus of echinoderms. Followed by the dermis, including a thick layer of connective tissue and muscle layer. Muscles can be divided into outer annular muscles and inner longitudinal muscles. The longitudinal muscles on the reverse side are developed, and contraction can bend the wrist. Within the muscle layer is a layer of body cavity membrane (peritoneum). The bones of echinoderms are formed by mesoderm and belong to endoskeleton, which is located in the connective tissue of the body wall. It is a grid-like skeleton formed by many separated small bone fragments with different shapes connected by connective tissues, and is composed of calcium salt doped with 10% magnesium carbonate. There are holes in the small bone fragments, which can not only reduce weight, but also increase strength. Each small bone fragment is formed by a cell in the dermis secreting a crystal, surrounding the crystal and then secreting and accumulating calcium salt by the surrounding cells, so the bone fragment can grow with the growth of animals. The size, shape and grid arrangement of bone fragments are determined by the structure and arrangement of dermal cells. In addition to bone fragments, there are some bone components scattered on the body surface, such as spine, pedi-cellaria and paxilla, to prevent and eliminate the deposits on the body surface. Among them, some forked spines have no stalks, and some have stalks. Forked spines are very common in the order of seagoing and ratchet pincers. They are composed of small bone plates, which are pincers or scissors-shaped, and are pulled and controlled by a pair of antagonistic muscles at the base. Some forked spines are arranged in a circle around the spines. There are separated umbrella-shaped bone fragments on the obverse surface of the starfish with banded orders, and there are many movable spines on the umbrella surface, which is the spinous process bundle, which is suitable for cave life on sand surface. In addition to thorns and spines, there are a large number of papulae on the epidermis, and its structure and function will be described in the breathing section. [ 1]
eye
Starfish has no specialized eyes. It has a red eye spot at the end of each wrist, which may be an important sensory area of its light. Most starfish are negative phototaxis and don't like light, so they mostly move at night. Although starfish have no eyes, they have many chemoreceptors, which can detect the source of food in water and find food quickly. Take starfish as an example. In this system, there is a main pipe in each radiating wrist, and all of them are connected with the pipe located in the mouth area. In most starfish, the porous plate on the body surface is connected with the circular pipe, which may allow the water to enter and mix with the body fluids inside. A short, lateral tube extending from each main pipe is used to input water to the foot of the pipe. Each tube foot has an ampulla, which is a muscular structure. When the ampulla contracts, the liquid in it is forced to enter the tube foot, making it elongate. tube foot
Starfish pictures
Its shape can be continuously changed, because the liquid in the water pipe system can be continuously introduced into the pipe foot through muscle activity.
spine
Starfish is an echinoderm, and its body surface is covered with rough spines, just like other echinoderms, such as sea-tailed snakes and sand money. Their skins are like thorns.
5 internal structure
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Starfish, headless, chest, only mouth and mouth. Its body is like a pentagon, which is radially symmetrical. The skin of the whole body is rough, and there are many scraggy's "bumps" on the body surface, called spinous processes, which are formed by the calcareous endoskeleton protruding from the surface skin. On the flat and flexible five-shot-shaped body plate, there are five thick wrists, and there is a step groove in the middle line of the wrists, and several rows of tube feet with suction cups at the end extend out of the groove. Starfish have a real body cavity, and a part of the body cavity extends out of the body to form some tubes that extend out of the body. This kind of elongated tube is called the tube foot, which is the motor and sensory organ of starfish. There is a sucker at the end of each tube foot. Starfish use the movement of the tube foot and the suction of the sucker on the tube foot to crawl and catch prey on the seabed.
Water pipe system
Starfish have a water pipe system inside each wrist. The water pipe system connects the pipe foot with the water inlet. When seawater enters the water pipe system, part of it passes through the water inlet and part of it passes through the pipe foot. The water inlet is also connected with the pipe foot and the water pipe system.
respiratory system
The respiratory organ of starfish is skin gill. Dermatobranchial is a membranous protrusion protruding from between bone plates, and its inner surface communicates with body cavity. Dermatobranchials are simple or branched, and individual ones are scattered or aggregated into dermbranchial areas. The skin and gills of starfish can increase the ability and area of breathing. It's like a fish breathing through its gills in the water.
digestive system
The mouth of the starfish is located in the center of the oral surface, and it opens into the heart and stomach first, and then, the pyloric stomach second through a short esophagus. Each arm also contains two pyloric caecum, a long hollow tube, which branches outward from the pylorus of the stomach. Each pyloric caecum is lined with a series of digestive glands, which secrete digestive enzymes and absorb nutrients from food. The small intestine runs from the upper body near the center of the upper surface of the stomach pylorus to open in the anus.
Starfish has a flat body, so its digestive system is particularly short and straight. From the mouth through the very short esophagus, through the wider stoma stomach, pyloric stomach, and then through a short abdomen to the anus of the mouth. There is a sphincter around the mouth, which can be contracted to make the mouth slightly larger to swallow slightly larger food. Because the digestive tract of starfish is very short and its capacity is limited, it first digests and decomposes food in vitro and then absorbs it in the body.
nervous system
Starfish have a fairly complex nervous system and a distributed brain. They have an interlaced neural network called plexus, which lies inside, and below, on the skin. There is also a central nerve ring around the esophagus, which sends to the radial nerves of each arm, usually parallel to the branches of the aquatic vascular system. All these connections form a brain. The ring nerve and radial nerve coordinate the balance and orientation system of starfish.
Although starfish don't have many definitions of sensory input, they are sensitive to touch, light, temperature, direction, and the state of water around them [17]. Starfish are found to be sensitive to touch on pins, spines, and pedicellariae, while the eye points at the end of light are light-sensitive foot tubes, especially those used in prompting rays, chemicals and locating odor sources such as food.
Each eye point contains a monocular mass, and each composed of pigment epithelial cells responds to light and narrow sensory cells, which are located between them. Each monocular is covered by a thick, transparent stratum corneum, which both protects them and acts as a lens. Many starfish also have a single photoreceptor cell in their bodies and can respond to light even if their eye spots are covered. [2]
6 predation
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Starfish are carnivores, which can feed on all kinds of invertebrates, especially shellfish, crustaceans, polychaetes and even fish. Some of them are monogamous, for example, many species usually only eat bivalves. There are also polyphagous or omnivorous species. There are basically three ways to feed: most starfish have long flexible wrists, and there are suckers on the tube feet, and most of them feed on bivalves. When feeding, their bodies are on the shells, and their wrists are sucked on both sides of the shells. Due to the vacuum effect of the suckers at the end of the tube feet, the pulling force is enough to open the shell mouth of bivalves, and the starfish immediately turns out the spouted stomach and inserts it into the shell mouth, and secretes digestive enzymes until the adductor muscle and internal organs are partially digested, and the shell is completely opened. Some species with short wrists and no sucker on the tube feet feed on smaller animals, such as small crustaceans. When feeding, the whole food is swallowed and digested in the stomach instead of in vitro. The species of deep-sea life feed by cilia filtration, and the sediment and organic matter falling on the body surface are swept into the step ditch by cilia action to form food rope, and then sent into the mouth, such as Acer starfish. Another example is Henricia, which has cilia in the gastric caecum, and relies on the movement of cilia to help suck food into the stomach. The digestive tract of starfish is also arranged in five spokes, and the mouth is located in the center of the mouth surface, surrounded by a periosteal membrane, on which there are cricoid muscles and sphincter muscles to adjust the expansion and contraction of the mouth. Behind the mouth is the esophagus, which is very short and then enters the swollen stomach. There is horizontal contraction on the stomach wall, which divides the stomach into a cardiac stomach near the mouth surface and a smaller pyloric stomach near the mouth surface. When taking food, the stomach of the spray door is often everted, and the food is wrapped and then retracted together. There are 2 ~10 gastric bands originating from the body cavity membrane on the stomach wall, which are connected to the bone plate. A pyloric canal extends from the pyloric stomach to each wrist, and immediately divides into two branches after entering the wrist, reaching the end of the wrist. Along the way, pyloric canal branched off to both sides, surrounded by a large number of glandular cells to form pyloriccecvm, which is actually a digestive gland, also called liver, and has the functions of secreting digestive enzymes, absorbing and storing nutrients. The pyloric stomach is followed by a short intestine, with five rectal cecvm around the rectum at the end of the intestine, and finally a small anal opening in the center of the stoma. Some species don't even have intestines, and indigestible food is usually still spit out through the mouth. The inner wall of digestive tract is covered with ciliated epithelium, and there are well-developed glandular cells on the gastric wall of stoma to secrete digestive enzymes, especially the pyloric caecum can secrete protease, amylase and lipase. Food can be partially digested in vitro, mainly extracellular in the stomach, and intracellular in the pyloric caecum. [ 1]
Predation process
Starfish usually move slowly or lie quietly on the bottom of the sea. Once they encounter shellfish such as oysters, they suddenly jump up, hold their prey tightly with their wrists, and then use their powerful suction cups to pull the closed shells away with a pulling force of more than 1 kg. Then they turn out from their mouths with their stomachs, squeeze into the shells, wrap them around their bodies, and secrete digestive juice, which is ten times larger than their mouths. After eating the prey, the stomach and digested food are slowly taken back from the mouth, while the shells and a lot of food residues are abandoned outside the body. Because starfish digests food in vitro, it doesn't have to deal with food ten times larger than its mouth.
Predator
Starfish mainly prey on some slow-moving marine animals, such as shellfish, sea urchins, crabs and anemones. And eat corals. Starfish has a strong digestive ability. It can spit out its stomach from its mouth, choose food directly, roll up the part it wants to eat, and then retract it into its stomach together with its stomach.
It often adopts a slow and tortuous strategy to approach the prey slowly, catch the prey with the tube foot on the wrist and wrap the whole body around it, spit out the stomach bag from its mouth, and use digestive enzymes to dissolve the prey in vitro and be absorbed by it.
Starfish eat a lot, and a starfish larva eats more than half of its own weight in a day.
7 environmental value
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The Leibniz Institute of Oceanography in Germany has published a communique saying that the latest research has found that echinoderms such as starfish play an important role in the marine carbon cycle, and they can directly absorb carbon from seawater in the process of forming exoskeletons.
Echinoderm is an invertebrate living on the seabed, which is divided into five categories: starfish, sea urchin, ophiopoda, sea cucumber and sea lily, and its figure covers all oceans. Studies have found that echinoderms absorb carbon from seawater and form exoskeletons in the form of inorganic salts (such as calcium carbonate). After their death, most of the carbon-containing substances in their bodies will remain on the seabed, thus reducing the carbon entering the atmosphere from the ocean. In this way, echinoderms absorb about 1 100 million tons of carbon every year.
It was previously known that after the greenhouse gases produced by burning fossil fuels enter the ocean, the acidity of seawater will rise, hurting coral reefs and shellfish. This time, the researchers found that acidic seawater is also very harmful to echinoderms, making it impossible for such creatures to form a solid calcium-containing exoskeleton.
8 medicinal value
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The chemical composition contains starfish saponin A and B.
Pharmacological action starfish saponin can inactivate sperm, and induce ovulation and ovulation.
Sexual taste is salty; Sexual equality
Return to the heart; Stomach; Large intestine meridian
The function is mainly to detoxify and dissipate stagnation; Regulating stomach and relieving pain. Indications for goiter; Laplacia; Stomach pain and pantothenic acid; Diarrhea otitis media.
Administration and dosage for oral administration: decoction, 20-30g；; At the end of research, 3g at a time.
Various scholars discussed the "Records of Medicinal Animals in China": it has the functions of regulating stomach, relieving pain, relieving acid, stopping diarrhea and calming down. Indications: hyperacidity, gastric ulcer, diarrhea, epilepsy, etc. [3]
9 Special functions
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Starfish are covered with "monitors"
Starfish, a marine animal covered with echinoderms, has a strange star-shaped body. It usually has five long tentacles on its disk-shaped body, but it can't see its eyes. People always think that starfish rely on these tentacles to identify their direction, but they are not. Studies by scientists in the United States and Israel have found that starfish are all "monitors". Why can starfish use their bodies to see everything? Yes, why can starfish use their bodies to see everything?
It turns out that starfish have many tiny crystals on their echinoderm skin, and each crystal can play the role of eyes to get the information around them. Scientists dissected the starfish, and found that every tiny crystal on the spiny skin of the starfish is a perfect lens, which is known to be much smaller than the lens made by human beings with existing high technology. Numerous lenses in the starfish's echinoderm have the property of focusing light, which enables starfish to observe information from all directions at the same time and grasp the surrounding situation in time. Prior to this, scientists thought that starfish echinoderm was highly sensitive, which could decide what kind of hidden preventive measures to take by changing the intensity of light around the body, and also could confuse the "enemy" by changing its own color. Scientists say that this unusual visual system on starfish has been discovered for the first time. Scientists predict that copying this tiny lens will make a breakthrough in optical technology and printing technology.
starfish
Ecological balance starfish is an indispensable link in the marine food chain. Its predation plays a role in maintaining the balance of biota. For example, on the west coast of the United States, there is a kind of spiny starfish that often preys on sea rainbow attached to rocks. In this way, it can prevent the excessive reproduction of the sea rainbow and prevent the sea rainbow from invading the territory of other creatures, so as to maintain the balance of the biota.
Regenerative ability
The unique skill of starfish is that it has the skill of being in two places at once. If the starfish is torn into several pieces and thrown into the sea, each piece will soon grow back the lost part, thus growing into several complete new starfish. For example, a sand starfish can grow a complete new starfish by keeping its wrist one centimeter long, while some starfish are even more capable, and a complete new starfish can grow with only a remnant arm. Starfish can regenerate naturally after their wrists and body plates are damaged or cut by themselves. Any part of a starfish can regenerate a new starfish [4]. Because starfish has such amazing regeneration ability, it is a trivial matter to have a broken arm and a missing limb. It is known that scientists are exploring the mystery of the regeneration ability of starfish in order to get inspiration from it and seek a new medical method for mankind. Scientists have found that when starfish are injured, backup cells are activated. These cells contain all the genes of the missing parts of the body and cooperate with other organizations to regenerate the lost wrist or other parts.
Therefore, some kinds of starfish have evolved the ability of asexual reproduction through this super regeneration method, and they do not need to mate. But most starfish usually don't reproduce asexually.
10 hazard control
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Main hazards
According to the latest report in 2007, more than half of the 25,000 square kilometers of coral reefs in the Philippines were attacked by starfish. Starfish are also terrible.
Since 2006, a large number of starfish have burst out in the northern coastal areas of China, with a density as high as 300/m2. During the peak period, more than 500 kilograms of starfish can be picked and caught in 3-5 mu of sea area every day. Starfish are mainly concentrated in Laoshan Mountain, Jiaozhou Bay, Tangdao Bay and Jiaonan sea area, and frantically eat abalone, Philippine clam, scallop and other cultured economic shellfish. One starfish 1 day can eat more than a dozen scallops, and the food intake is amazing, causing huge economic losses to shellfish farming. In 2006 alone, the loss of abalone culture caused by starfish disaster in Jiaonan area reached more than 40 million yuan; In 2007, only the variegated clam culture of Qingdao Haifeng Aquaculture Company lost more than 30 million yuan due to starfish swallowing. According to preliminary statistics, since March 2007, 60% of the160,000 mu of Ruditapes philippinarum cultured in Jiaozhou Bay has been invaded by starfish, with the disaster rate reaching 70% ~ 80%, and in some sea areas it is as high as 90%. A 60-horsepower fish boat can catch 800 ~1000 kg of starfish in Jiaozhou Bay culture area one day, which has caused heavy losses to cultured fishermen. Heavy losses, then.
Prevention and cure method
Controlling the overflow of starfish has attracted great attention of governments and experts all over the world, and reduced its shellfish.
starfish
The economic loss of aquaculture is imminent. In Japan, millions of dollars are spent every year to control the harm of starfish, and oyster farms in the United States spend a lot of manpower and financial resources to deal with its harm every year. At the same time, the harm of starfish has attracted great attention of governments at all levels.
In view of the serious negative impact of starfish flooding on fishery production, combined with the current production practice, the following research countermeasures are mainly explored:
1. Strengthen propaganda and guidance, and strengthen fishermen's understanding of the harm of starfish. From a scientific point of view, we should do a good job in publicizing and guiding fishermen and eliminate their paralysis consciousness. When necessary, trawling and manual fishing were adopted, and ground rolling cages were laid on the seabed outside the culture area for trapping, and the effects of various fishing methods were compared and studied. Because of the strong reproductive ability of starfish, the captured starfish should be concentrated on land treatment, which can be used to improve cohesive soil, etc. It is forbidden to shred them and throw them back into the sea to prevent them from regenerating. Starfish is very dangerous. Don't let it breed. It grows like a gecko's tail, and one end can become countless.
Biological control Exploring the species and quantity of natural enemies of starfish, understanding the mechanism of killing starfish larvae, and using the method of breeding natural enemies of starfish to prevent the harm of starfish to cultured shellfish is an environmental protection method worth promoting.
3. Turning waste into treasure and turning harm into profit. As an edible part of starfish, starfish yellow is rich in nutrients such as trace elements, vitamins and fats, and can be processed and utilized as a nutritious and non-toxic new marine food raw material. In recent years, the medicinal value of starfish has been paid more and more attention, and many marine pharmaceutical enterprises have developed starfish nutrient capsules and other products, which have remarkable effects on regulating human immune function, eliminating diseases and strengthening the body. In addition, starfish can also be dried in the sun to make agricultural fertilizer and made into handicrafts in coastal tourist cities, thus increasing the added value. Marine science and technology workers should vigorously study and publicize the medicinal and edible value of starfish, quickly transform scientific and technological achievements into productive forces, assist enterprises to take the road of large-scale processing of starfish, let people accept and recognize the important contribution of starfish to mankind, and consciously and actively catch starfish, so as to turn waste into treasure and harm into benefit.
4. Establish a corresponding starfish control committee and organize professional researchers to investigate the distribution, harm and development trend of starfish along the coast of Qingdao, especially in Jiaozhou Bay. Formulate corresponding laws and regulations, strictly inspect and quarantine ships entering different places, and limit the transmission of tools and carriers carrying starfish larvae between different sea areas.
5. Strengthen supervision and inspection, and strictly regulate operation behavior. The time for removing starfish should be determined according to the early warning situation, and it can only be implemented after being approved by the fishery administration department. The use of nets is limited to large mesh cage nets or conch trawls, and the illegal operation in the name of removing starfish and destroying fishery resources will be severely punished according to relevant regulations. [5]
1 1 Reproduction
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Starfish are echinoderms that live in the sea. They have strong reproductive ability and can live for 35 years. There are about 1500 species of starfish in the world, and most of them are propagated by in vitro fertilization without mating. Male starfish have a pair of testicles on each wrist. They discharge a lot of sperm into the water, and females also discharge thousands of eggs through ovaries on both sides of their wrists. Sperm and egg meet in water, complete fertilization and form new life. From fertilized eggs, larvae are born, that is, small starfish. So make their eggs sterile.
Starfish (2 1 piece)
Some researchers have found that some starfish have the habit of seasonal pairing, that is, the male starfish lies on top of the female starfish, and the five wrists are staggered. This behavior is considered to be related to reproduction, but its real function has not been confirmed.