There are two large claws on its velvet like hair, so Chongming people call "the old crab." Chongming Island in the background to the Yangtze River Estuary. The world's major rivers and lakes, a total of 300 kinds of crabs, which are available to eat about 20 species, the most prestigious to the number of our Chinese mitten. Chinese mitten crab eriocheir Decapoda (decapoda) square crab Division (grapsidae) mitten crab is a crustacean. Also known as crab, crab, fresh water crabs, crabs, or crabs. Economic crabs. Mitten crab distribution and migration of natural distribution area, mainly in northern Asia, North West and China. China Liaoning Yalu River from North Port, south Jiulong River in Fujian, Hubei Yichang Three Gorges West until the mouth are distributed. As early as 1000 years ago had been the living habits of the crab, in particular reproductive migratory have some knowledge of the law. In recent years, with the Crab and releasing the artificial cultivation of proliferation, this crab has been all over the country, but the quality of the Yangtze River downstream of Yangcheng Lake hairy crabs, and crabs of the most famous Hebei Shengfang. Early 20th century, with the crab ship transplanted to Germany, then spread along the Rhine, now live in many European countries over the waters. Features nearly round body, carapace on the back of the grass green or dark green, belly white, the amount of margin of carapace with 4 sharp teeth suddenly, the front edge of the odontoid also with 4, 4 teeth small and obvious. Abdomen flat, female body oval to round abdomen, the male body was slender bell-shaped abdomen; but the individual male and female crab abdomen are triangular stage, difficult to distinguish. Chelipeds for feeding and against the enemy, both inside and outside edge of the palm of their dense hair, mitten crab, hence the name. Four pairs of walking legs are the main organs of reptiles, the long end of the section have a sharp front teeth. Female pleopod 4 pairs in 2 to 5 abdominal section, double-limb-based, dense _set_ae, mainly within the limb attached to the eggs. Male crab only the first pleopod 1 and 2, especially into the transfer device. (See color pictures Chinese mitten crab) Biological characteristics of Chinese mitten crab habitat in freshwater lakes and rivers, but reproduction in estuarine brackish waters; 6 to 7 months each year new students enter the freshwater crab anadromous, the habitat in rivers, Hudang the shore. Hi burrowing door, or hidden in the gravel, plants leaves. Burrowing time depends mainly on one pair of chelipeds, walking legs only play a supporting role. To aquatic plants, benthic animals, detritus and animal carcasses for food. Captured by the chelipeds when feeding, and then sent to the port side of the food. Nutritional condition is good, then crab weighing up to 50 to 70 grams, up to 150 grams, and maturation, can join with the 2nd instar crab reproductive migration. Such as stocking density, or slow growth, then 2 years old when the gonad is difficult to mature, can not participate in reproductive migration. Chinese mitten crab in the rivers and lakes usually grow to 2 years old, from late September (Harvest) for the green crab shell from the rapidly developing gonad, female 30 to 40 days before molting crab reproductive index to surge 0.36% 10 to 15 percent. To 10 months late (dew, frost season), most of the gonad has developed into the first stage Ⅳ, then leave the rivers, shallow lakes and estuaries for the reproductive migration. Early November (beginning of winter), after a cluster on the junction of brackish estuarine shallow waters and began mating. In the Yangtze River, Chinese mitten crab breeding areas of salinity of 8 to 15, the water temperature is 6 ~ 12 ℃, time in December of that year to next March. Mating male crabs to female crab chelipeds vise pereiopod, and the transfer device aimed at the female end of the hole, the sperm enter the female crab is satisfied within the seminal vesicle. The entire mating process lasted a few minutes to 1 hour. After mating, female crabs usually 7 to 16 hours to lay eggs. Fertilized eggs attached to the female crab's _set_ae on ventral limb. Water temperature 10 ~ 17 ℃ in the case, the fertilized egg by 30 to 60 days after hatching zoea, zooplankton in the shallow estuary more than 30 days after molt five times, and then into the megalopa stage. Planktonic and benthic life at this time concurrently, and can be traced back to the upstream lakes. Megalopa for 6 to 10 days from crab shell, started crawling camp benthic life. All crabs in the spawning pro after hatching, stay in the shallows of the estuary sand dunes, its carapace and limbs bryozoans, insects, etc. attached to the Tau Chi, the abdomen often parasitic crab slaves. Postpartum female crabs to the end of June beginning of July have been killed. From zoea, the female crab's life-age of 2, after the death of male crab is mating, female crabs shorter life expectancy than 2 months. Year life of the mature crab is only one year, and the dominant female. Slow maturation of the individual, longer life expectancy, some up to 3 to 4 years. Production of crab's flood season in early October to early November (before the dew to the beginning of winter), about 40 days. Bamboo fish trap fishing tools for the main screen, _set_-net in, to pull the net, seine net. Estuarine shallow water fishing season in early November to late March (winter solstice equinox Li), which points in early February (the beginning of spring) the previous winter crab and early February (the beginning of spring) after the spring flood season 2 crabs, the main tool for crab fishing trawl. Since the late 1950s, due to a large number of estuaries along the coast began to build gates, resulting in pro-reproductive migratory crab and crab upstream obstruction, sharply the amount of resources since the 1960s. 1969 Chongming Island in the Yangtze River near the mouth of the huge Chinese mitten crab found in natural products Naeba. There appear 1 to 2 year flood, flood peak than in early June. Many parts of the country back to the fishing crab stocking, the survival rate of 1 to 5%, and achieved a certain multiplier effect. However, due to resource fluctuations of the Crab (normal year's production came from only 1 / 10 ~ 1 / 50), so the production can not be stable. Economic value of the Chinese mitten crab delicious and nutritious, always been regarded as the top grade. Per 100 grams edible portion of crab protein 14%, fat 5.9%, 7% carbohydrates, also contain vitamin a, riboflavin, niacin, and its heat more than the general level of nutrition of fish.
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No. 2
【Name】 Chinese mitten crab species [Latin name] Eriocheir sinensis 【English name】 Chinese Mitten Crab [Chinese] commonly known as crabs, crab, crab There are two large claws on its velvet like hair, so Chongming people call "the old crab." Chongming Island in the background to the Yangtze River Estuary. The world's major rivers and lakes, a total of 300 kinds of crabs, which are available to eat about 20 species, the most prestigious to the number of our Chinese mitten. Chinese mitten crab Eriocheir Decapoda (Decapoda) square crab Division (Grapsidae) mitten crab is a crustacean. Also known as crab, crab, fresh water crabs, crabs, or crabs. Economic crabs. Mitten crab distribution and migration of natural distribution area, mainly in northern Asia, North West and China. China Liaoning Yalu River from North Port, south Jiulong River in Fujian, Hubei Yichang Three Gorges West until the mouth are distributed. As early as 1000 years ago had been the living habits of the crab, in particular reproductive migratory have some knowledge of the law. In recent years, with the Crab and releasing the artificial cultivation of proliferation, this crab has been all over the country, but the quality of the Yangtze River downstream of Yangcheng Lake hairy crabs, and crabs of the most famous Hebei Shengfang. Early 20th century, with the crab ship transplanted to Germany, then spread along the Rhine, now live in many European countries over the waters. Features nearly round body, carapace on the back of the grass green or dark green, belly white, the amount of margin of carapace with 4 sharp teeth suddenly, the front edge of the odontoid also with 4, 4 teeth small and obvious. Abdomen flat, female body oval to round abdomen, the male body was slender bell-shaped abdomen; but the individual male and female crab abdomen are triangular stage, difficult to distinguish. Chelipeds for feeding and against the enemy, both inside and outside edge of the palm of their dense hair, mitten crab, hence the name. Four pairs of walking legs are the main organs of reptiles, the long end of the section have a sharp front teeth. Female pleopod 4 pairs in 2 to 5 abdominal section, double-limb-based, dense _set_ae, mainly within the limb attached to the eggs. Male crab only the first pleopod 1 and 2, especially into the transfer device. (See color pictures Chinese mitten crab) Biological characteristics of Chinese mitten crab habitat in freshwater lakes and rivers, but reproduction in estuarine brackish waters; 6 to 7 months each year new students enter the freshwater crab anadromous, the habitat in rivers, Hudang the shore. Hi burrowing door, or hidden in the gravel, plants leaves. Burrowing time depends mainly on one pair of chelipeds, walking legs only play a supporting role. To aquatic plants, benthic animals, detritus and animal carcasses for food. Captured by the chelipeds when feeding, and then sent to the port side of the food. Nutritional condition is good, then crab weighing up to 50 to 70 grams, up to 150 grams, and maturation, can join with the 2nd instar crab reproductive migration. Such as stocking density, or slow growth, then 2 years old when the gonad is difficult to mature, can not participate in reproductive migration. Pollution-free farming techniques] [Chinese mitten crab In recent years, trembling disease crab, crab slave outbreaks of disease and other diseases are more serious. In 1999, parts of the crab production in Jiangsu Zengyin trembling disease outbreaks and suffered heavy losses, some production units is almost annihilated. In this regard, since last year, the provincial, city and county authorities at all levels under the guidance of fish, crab production gradually began around the health of breeding experiments and demonstrations, and with remarkable results. Author crab healthy culture of the main technical measures summarized as follows: 1 strict Larvae off 1.1 to be pure breed At present, China mainly from crab farming three major river systems, namely the Yangtze River, Liaohe River and Ou River system. Practice has proved that different river systems of the crab, only the environmental conditions in their under water in order to play its regional growth advantage, achieved good economic results. Larvae and Juveniles of the Yangtze River 1.1.1 Features and Benefits Yangtze River crab's carapace is light yellow, oval-shaped, sharp side of Hebei, which marked the fourth side of the tooth, the amount of depression evident among teeth; the second step and the third walking legs and other long enough, the fourth side of the teeth on the diameter and the third pereiopod length ratio of 1:20 (this ratio is the Yangtze River and other water Larvae Larvae key difference), pereiopod golden hair, and the second, without _set_ae on the three-legged. Yangtze River crab has many advantages, the biggest advantage of fast growth, individual crab was significantly greater than other water species. 1.1.2 The preferred pro-choice in the order: the Yangtze River> Lakes> Ponds 1.1.3 seed the preferred choice in the order: natural (fishing) Yangtze river crab seed> artificial breeding of the Yangtze river crab seed> production to large-sized crabs for the artificial propagation of the parents of the Yangtze River Chinese mitten crab fry. 1.2 quality to be excellent 1.2.1 correctly identify precocious Larvae, Larvae and Juveniles of the survival rate increased Precocious puberty is when the Crab Larvae, Larvae and Juveniles in the developed into the year, the individual is not, usually 20 grams, gonadal development and maturation of crabs already. Larvae and Juveniles in the following year for commodities in this crab production, the vast majority of deaths due to molting problems, and thus to the production of crab serious economic losses. Correctly identify ways of precocious puberty Larvae of four to see: (1) see Larvae of the abdomen. Such as the female crab abdomen has become nearly circular, which has shown a group navel, around the navel has long hair, shell and the fourth, five wider, this indicates that this crab has been precocious; male crab shell and the transfer device Ruoyi develop into white hard bone of the tubes, it has been shown that sexually mature male crabs. (2) See Larvae of the chelipeds, walking legs inside of the palm section of the Department has no hair, if not as a continuous thin and short hair; precocious puberty Larvae chelipeds or walking legs long hair thick and dense, darker. (3) spectacle of crab carapace color and pattern. Back to normal Larvae Carapace light yellow color, and sexual maturity of Larvae and Juveniles carapace is dark green or blue; normal Larvae back relatively flat, undulating obvious, but sexually mature individuals like the back are uneven. (4) to see Larvae of gonadal development status. Open the carapace, to see if there are two purple on the liver strips, and even eggs, compared with sexually mature ovaries; have two white strips, for the mature testis. If only to see dry yellow liver, indicates that the immature gonads. 1.2.3 Education Larvae from the best conditions. Since education Larvae high survival rate, disease resistance, fast growth, the quality is better than outsourcing Larvae. 2 crab dredging pool disinfection Crab like to inhabit rivers and lakes of mud shore or beach caves, or hidden in the gravel, plants leaves. In artificial breeding, you can change the characteristics of their cave. According to the survey observations, ponds into crab burrowing rate is relatively low, and females more than males. Most of the crab buried in the sediment, revealing only the eyes above the mouthparts and antennae, to maintain breathing. We believe that the mass of sediment quality crab is one of the key factors of production. Now it seems that one of the key risk factors of crab that is clean of sediment or not. In production, we can take the following measures to improve, to improve the quality of the end to meet the growing needs of live crab. 2.1 All around the pond at the end of each year mostly dry pond by dredging (sediment less than 15Cm), after exposure, and then 100-100 Kg / acre lime clear pond. 2.2 can be used underwater by suction dredging machines and other means to complete. 2.3 water aerobics or aerobics aerobics, to ensure that dissolved oxygen not less than 5mg / L. 2.4 to promote the use of feeding photosynthetic bacteria and other microorganisms, which can effectively absorb the water, underwater toxic substances. Its role is as follows: (1) clean water, improved water environment (which can absorb hydrogen sulfide, ammonia salts and other toxic substances), reducing their concentration in the water; (2) can effectively improve the dissolved oxygen, stable PH value of water; (3) photosynthetic bacteria itself as a high protein (up to 65% content), can significantly improve the yield of crab; (4) can effectively improve the immunity of crab; (5) can reduce the cost of production; (6) to produce green products, non-polluting products. 3 Adjust stocking model 3.1 appropriate density. Change Password support for the thin place, usually only 500-600 stocked / acre, so that there is an ample living crab, growth space. 3.2 moderate size. Usually only 100-200 / kg, in order to ensure that the crab market size. 3.3 Timely stocking. Put up for the winter and spring change, usually in late February to early March, when the water temperature 8-12 ℃. 3.4 After first holding stocking. "Holding" is the Larvae of the transition period before stocking. Larvae after holding after stocking, can greatly improve the survival rate Xiatang. Note that holding the length of time, depending on water temperature and water plants grow in the circumstances. 4. Planting plants Plants growing in today's efforts to promote eco-crab a very effective means. As the saying goes: "crab size, look at plants." 4.1 The main purpose of growing plants From the dispersion, can take full advantage of the water, the use of three-dimensional sound distribution of crab, that is, the middle body of water suitable for distribution. 4.2 plants species You can choose Elodea, Vallisneria, Hydrilla, etc., but Elodea is the best, its high nutritional value and vitality of an exceptionally strong, year-round growth. 4.3 grass area General control about 60% of the water, if too close, to open an every 10-15m 3-5m wide channel bottom to ensure there is enough light. 4.4 Time grass Generally choose to Tomb Sweeping Festival, premature too late. 4.5 Planting methods Elodea and Hydrilla dominated by asexual reproduction, to cut the stem cuttings of the segmentation method, the amount per acre 25-30kg; hard to sow grass-based, per acre seed quantity 0.1kg. 4.6 Management of (1) To timely timely fertilization (fertilizer, basal to foot; inorganic fertilizer in moderation, to efforts to promote the use of calcium phosphate). (2) plants grown in Larvae before stocking, to ensure Larvae xiatangji plants grow there before, or crab grass shoots were feeding affect the plants grow. 5 improved feeding technology Feed quality is a big crab, crab production of good material guarantee. (1) Ching Ming hours to more than 300 kg per mu put fresh clams, mussels and other snail to serve as the basis for food throughout the year. (2) to do regular feeding, positioning, qualitative, quantitative. (3) preparation of mixed artificial feed, it is best to feed made of surface strip or other benefit groups like the shape of the crab feed. (4) in the crab in the early growth of the main feeding wheat, pumpkin, Valley, cake, etc., during which promote feeding malt (malt feeding can not guarantee its rot 1-2 days), and the remaining feed should boil cooked feeding. (5) crab's life, to go through several molting. Soma increases, the shape changes, and limb regeneration are all formed after each molting. Growth throughout the entire shell crab, living process. Therefore, usually to moderate feeding molting hormone, and molting hormone fed with feed fed in time to appropriately separate; In addition, during the crab shell, new ones should wash water injection to maintain micro-flow, can effectively stimulate the crab shell. (6) throughout the breeding cycle, but also the amount spilled lime, water purification on the one hand, on the one hand increase the calcium content in water body, to prepare for the need of molting several times. 6 Science conditioning water Healthy crab on the water quality of the environment is very high, we need to scientifically conditioning water. 6.1 Water quality indicators Requires transparency 35-40cm, dissolved oxygen in the 5 mg / L or more, PH value 7.5 - 8.5, ammonia concentration 0.2-0.5mg / L. These water quality indicators in clinical testing through the use of water boxes and other means to detect, in order to take some measures (mainly simulated natural environment) of water necessary, useful and timely regulation. 6.2 water regulation Larvae stocked in late February early March, early, water depth control in the 0.6-0. 8 m ,5-7 月份 water depth in the 0.8-1.0 m ,8-10 月份 lies in the 1.0-1.2 m depth between. Spring and autumn, changing the water once a week, each time deeper 30-40 cm. Side to side when changing the water irrigation schedule, changing the water temperature should not exceed ± 5 ℃. Such as silt bottom plot more transparency, color darker, deep black color of crab carapace, abdomen water, rust, yellow end pereiopod, with fresh lime per acre 7.5-15 kg, into the water Quanchiposa, continuous use 2-3 times, at intervals of 5-7 days, can regulate water quality, increase water calcium concentration is conducive to the growth of crab and crab color changes. 6.3 Notes (1) must promptly change the water, changing the water amount to improve the environment, reduce the temperature. Appropriate temperature for crab molting 25-28 ℃. (2) raw stone is not appropriate to use, reuse, common. If you frequently use, water hardness will be too large, reduce the dissolved oxygen, phosphate will be reduced. (3) fat to maintain a certain degree water, clams, mussels and other snail bait to promote biological growth and reproduction. (4) the implementation of crab fish polyculture. Crab fish polyculture can take advantage of the water space, improve feed utilization, water purification, improve pond water quality conditions. But the crab-based, can be adapted to stocking a small amount of silver carp, bighead, grass, bream, tilapia, but not stocked carp, herring and other benthic carnivorous fish. Note Fangtao. Chinese mitten crab in the rivers and lakes usually grow to 2 years old, from late September (Harvest) for the green crab shell from the rapidly developing gonad, female 30 to 40 days before molting crab reproductive index to surge 0.36% 10 to 15 percent. To 10 months late (dew, frost season), most of the gonad has developed into the first stage Ⅳ, then leave the rivers, shallow lakes and estuaries for the reproductive migration. Early November (beginning of winter), after a cluster on the junction of brackish estuarine shallow waters and began mating. In the Yangtze River, Chinese mitten crab breeding areas of salinity of 8 to 15, the water temperature is 6 ~ 12 ℃, time in December of that year to next March. Mating male crabs to female crab chelipeds vise pereiopod, and the transfer device aimed at the female end of the hole, the sperm enter the female crab is satisfied within the seminal vesicle. The entire mating process lasted a few minutes to 1 hour. After mating, female crabs usually 7 to 16 hours to lay eggs. Fertilized eggs attached to the female crab's _set_ae on ventral limb. Water temperature 10 ~ 17 ℃ in the case, the fertilized egg by 30 to 60 days after hatching zoea, zooplankton in the shallow estuary more than 30 days after molt five times, and then into the megalopa stage. Planktonic and benthic life at this time concurrently, and can be traced back to the upstream lakes. Megalopa for 6 to 10 days from crab shell, started crawling camp benthic life. All crabs in the spawning pro after hatching, stay in the shallows of the estuary sand dunes, its carapace and limbs bryozoans, insects, etc. attached to the Tau Chi, the abdomen often parasitic crab slaves. Postpartum female crabs to the end of June beginning of July have been killed. From zoea, the female crab's life-age of 2, after the death of male crab is mating, female crabs shorter life expectancy than 2 months. Year life of the mature crab is only one year, and the dominant female. Slow maturation of the individual, longer life expectancy, some up to 3 to 4 years. Production of crab's flood season in early October to early November (before the dew to the beginning of winter), about 40 days. Bamboo fish trap fishing tools for the main screen, _set_-net in, to pull the net, seine net. Estuarine shallow water fishing season in early November to late March (winter solstice equinox Li), which points in early February (the beginning of spring) the previous winter crab and early February (the beginning of spring) after the spring flood season 2 crabs, the main tool for crab fishing trawl. Since the late 1950s, due to a large number of estuaries along the coast began to build gates, resulting in pro-reproductive migratory crab and crab upstream obstruction, sharply the amount of resources since the 1960s. 1969 Chongming Island in the Yangtze River near the mouth of the huge Chinese mitten crab found in natural products Naeba. There appear 1 to 2 year flood, flood peak than in early June. Many parts of the country back to the fishing crab stocking, the survival rate of 1 to 5%, and achieved a certain multiplier effect. However, due to resource fluctuations of the Crab (normal year's production came from only 1 / 10 ~ 1 / 50), so the production can not be stable. Economic value of the Chinese mitten crab delicious and nutritious, always been regarded as the top grade. Per 100 grams edible portion of crab protein 14%, fat 5.9%, 7% carbohydrates, also contain vitamin A, riboflavin, niacin, and its heat more than the general level of nutrition of fish.
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Aquatic Sciences
Crab artificial breeding artificial breeding is the key to the production, only the ring is properly carried out, the production of artificial breeding can only be guaranteed in order to provide large quantity of good quality crab, crab by the development of aquaculture production services. The cultivation of live bait crab zoea, megalopa are omnivorous, plant food, animal feed, eat organic debris, especially eating plants and animals of live bait. Thus in the process of artificial breeding, training to improve living and production of food for zoea, megalopa provide a rich palatability of live bait, artificial crab nursery for doing a good job, improve the survival rate is very important, must be very attention. (1) live bait plant cultivation. Crab nursery plant production in the common live bait with Phaeodactylum tricornutum, Nitzschia closterium, flat algae, Chlorella and other unicellular algae. These algae are the palatability of crab zoea bait. The cultivation of live bait plant has the following general areas: First, the collection, separation and screening required for algae species, scientific research units to production units can be purchased. Second, the preparation of nutrient solution. Requirements according to the scale of production and overall planning, reasonable preparation. The third is the appropriate choice of training methods. Usually have indoor and outdoor concrete ponds develop small train. Need a large quantity of live bait culture method can be used outdoor concrete ponds, built facilities, improve pond, tool disinfection. Fourth, develop a good indoor cement pond algae species to migrate to within the outdoor mass production. Time of inoculation to be large to maintain a growth advantage, vaccination should be in sunny circumstances. Fifth, to strengthen production management, focusing on a certain amount of light, appropriate water temperature, salinity appropriate and adequate nutrition, to promote the continued growth and reproduction of algae, provide a steady stream of live bait source. Also note that the growth rate of algae culture tanks, promptly remove feeding zoea to prevent the density is too large, affecting algae growth, and replenish the pool of nutrients, the need to ensure sustainable growth of algae. (2) the cultivation of animal live bait. Crab zoea and megalopa eating animal feed for the rotifers and Artemia live. Rotifer culture is, first isolated by collecting, access to rotifer species, then of rotifer species in the test room for expansion of cultivation, when a certain number of rotifer species, for use when training a large area, then moved into the indoor concrete ponds or outdoor earthen ponds for large-scale production, you can regularly use screen tulle crab larvae feeding fish. The Artemia culture method is to first capture or purchase good quality Artemia, determined according to production needs to buy the number. Then feed on Artemia cultivation tanks, Jingxi eggs, incubation, separation and other processes, you can remove the feeding crab larvae.
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Thesaurus
Crab, maoxie, qingshuixie, rong'aoxie, rinsing live fresh water crab, river crab
Containing Phrases
China mitten crab Qinxiede Chill technology
China mitten crab artificiality grow seedlings technology
Basin cultivate China mitten crab Youxie
Announce city Jiang Fan China mitten crab speciality cooperative