To advocate small lobster , everybody to the point

Breeding habits of the ratio: the proportion of male and petticoat freshwater crayfish 3.0 to 8.0 cm in length and 8.1 ~ 13.5 cm in the two descriptions are petticoat than male team. Small size group of females accounted for 51.5% overall, 48.5% of male, female and male ratio of 1.06:1. Large-size group of females accounted for 55.9% overall, 44.1% male, male and female ###### ratio 1.17:1. Significantly more than large-sized group of females for the males behind mating the male and simple necrosis. Larger males, higher mortality, indicating that male life expectancy is shorter than females.
######ual maturity: freshwater crayfish become ######ually mature the following year, September to leave the mother to the second-year juveniles 7 August to ######ually adult eggs. From larvae to ######ual manhood, to the freshwater crayfish molt more than 11 times. 2 larval stages which moult, molt stage juvenile 9 times.
mating, spawning, egg digit and spawning Yan type: freshwater crayfish for the autumn and winter spawning type, spawning once a year, mating season, commonly in 7 to 12 months. A male shrimp can be met with a more than females mating, mating, the male chelipeds vise with shrimp shrimp chelipeds females, with females prop pereiopod, the females flip side. Calcium males and females of the transfer device connected seminal vesicle, male sperm shrimp into the direcotry onward the transfer of control of female shrimp seminal vesicle. After mating, as early as one week or at the peak of a month more females to lay eggs. Females from the base of the third pereiopod gonopore on ovulation and dismiss of more egg-shaped egg with resin and mantled the eggs, the eggs through the seminal vesicle, the gum-like substances in the seminal vesicles to promote the unlock of sperm among the sperm folder, so that the eggs fertilization. Finally, the glial-like substance wrapped around the abdomen females get fertilized egg, fertilized eggs attached to females drilling gastropods, and kept swinging gastropod egg hatching to assure that the essential dissolved oxygen. In ecology, the broodstock mating, we began to burrow, females during spawning and hatching eggs in underground caves and more complete. Freshwater crayfish spawning females increased with the length of the growth of the individual boosts. 10.0 ~ 0.9 cm length of females, the average egg load was 237 (Table 5). Spawning individuals collected the maximum length, 4.26 cm, spawning 397, the minimum length of 6.4 cm of individual eggs, eggs make 32.

hatching and larval development: egg output of females just for dark brown, eggs diameter of about 1.6 mm. Japanese savants Tetsuya Suko on the hatching of fertilized eggs of freshwater crayfish have been studied, presented at 7 ℃ water temperature conditions, the eggs hatch about 150 days; in 15 ℃ water conditions, the eggs hatch about 46 days; the water temperature at 22 ℃ under the conditions of incubation of fertilized eggs takes about 19 days. We have 24 ~ 26 ℃ of water temperature conditions, tests, 14 eggs hatched into larvae fracture of films for 15 days in the 20 ~ 22 ℃ of water temperature conditions, the fertilized egg incubation takes 20 to 25 days. If the water temperature is too low, the hatching eggs may take several months. This is our second year of the 3 ~ 5 months berried shrimp can see the reason. Some people scrutinized in the May berried shrimp, crayfish on the basis that water is a spring-spawning or spawning double a year, this is bad. Newly hatched larvae are about 5 to 6 mm, by the yolk nourishment, two days afterward developed into larvae molt. Larvae of about 6 to 7 mm, well-developed appendages, curved forehead between the eyes, the fashion and similar to adult shrimp. Two larvae spliced to the maternal belly, respiratory flow can be reasoned by maternal feeding organisms and plankton, while leaving the stand after the mother, but only languid to hike, it can only peregrination a short distance back to the maternal abdomen. In a second stage larvae and larval duration, when afflicted females, resulting in separation of females and juveniles far, the larvae can not be returned to the abdomen of female shrimp larvae will die. Two days after the molt larvae develop into larvae, total length of about 9 to 10 mm. At this time larvae remain spliced to the maternal abdomen, the shape is almost exactly the same as shrimp, larvae on the mother also has great persistence and with the mother to leave by the cave into the open water body to become juvenile. In the 24 ~ 28 ℃ of water temperature conditions, stage of larval evolution of freshwater crayfish is about 12 to 15 days.
growth and molting

freshwater crayfish and other crustaceans, have to slough off the surface of the carapace to complete the mutation of growth. In Wuhan, in mid-September juveniles from the mother's average absolute width of about 1.0 cm, mean weight of 0.04 grams, in the cage in the propagating to the end of November, the average length of 5.19 cm, average heaviness of 4.50 grams, the maximum aggregate length of 7.4 cm , heaviness 12.24 grams. Culture in ponds to the second year in July, the average total length of 10.2 cm, the average weight of 34.51 grams. Ponds in nice condition, just left the mother's growth of juvenile 2 to 3 months to reach mall size. The growing season may be others with weight acquisition.
freshwater crayfish shell and water temperature, nutrition and individual developmental stages are closely related. Usually 4 to 6 days the larvae molt once, leaving the mother into the open waters of the juvenile shrimp molt every 5 to 8 days time, post-juvenile molt intervals are generally 8 to 20 days. High water temperature, food is abundant, medium stage of development of drought. Molt interval is short. ######ually mature females, males generally molt l ~ 2 times a year. According to calculations, length of 8 to 11 m thick freshwater crayfish once every shed rind. Length can be increased by 1.3 cm. Freshwater crayfish molt occurred at night, under the conditions of artificial breeding, and sometimes during the day and also see their molt,GHD Purple Straighteners, but very infrequent. According to the activities and shrimp feeding condition, and molt molt cycle can be divided between the period of pre-molt, post-molting and molting of the four stages. Between molting period is the accumulation of freshwater crayfish of nutrients for the growth stage, at this stage of the strong feeding shrimp, crustaceans gradually harden; shell to stop pre-feeding from the freshwater crayfish ecdysis only until the starting of this stage is freshwater crayfish in preparation for the moult. Stop feeding crayfish, crustaceans in the calcium stone to the body's calcium transfer, the body's calcium stones larger, thinner shells, soft, and with the separation of the cortex. Molting of the freshwater crayfish from the beginning to the crustacean molting side entirely slough off by far, this stage lasted about ten minutes ranging from a few minutes, we observed mostly in the 5 to 10 minutes, the water too long crayfish and easy death. Late molting crayfish from the water to begin feeding only after molting, this stage of freshwater crustaceans crayfish crustaceans from the cortex to the process of evolution. Water from the cortex into the body, the body weight gain, additional; body calcium stones Calcium transfer to the cortex, cortical floors harden, thicken, become the carapace, the body of calcium stones eventually become very small. Some scholars abroad
molting period and later divided into the shell of soft shell, its molt cycle is divided into molt interval, molting early stage of molting period, the soft shell and the shell of the five stages of.

freshwater crayfish are omnivorous feeding animals, feeding mainly of alphabetical detritus of various cereals, cake, vegetables, Lusheng Mu grass, water the aquatic plants, the algae, zooplankton, aquatic insects, small animals and beast carcasses can benthic feeding, and dining artificial feed. In the 20 ~ 25 ℃ condition, freshwater crayfish feeding Potamogeton up every day and night to 3.2% from the body of jade, bamboo feeding up to 2.6% in food, water, peanut 1.1%, soybean repast 1.2%, artificial feed up to 2.8%, 4.9% fish feeding, and feeding larvae called up to 14.8% (Table 2), showing that the shrimp eating beast substances. In natural waters, because of its ability to lower predation in the food composition of the shrimp, more than 98% of vegetable factors (Table 3). Aquaculture sector in China has long mistakenly believe that fresh water crayfish to predator fish, species of large impair aquaculture. We did this freshwater crayfish of carp, grass carp, silver carp and Nile tilapia four fry and fingerling survival rate in rats, the tentative data show that: the four species and the survival of freshwater crayfish polyculture rate was 100%. Four varieties of fish and freshwater crayfish polyculture, the average survival rates were 90.0% and 77.2%, 80.4%, 87.2%, but not shrimp polyculture with freshwater crayfish, the average survival rates were 89.2%, 76.3%, 80.6% , 87.9%,GHD Purple Butterfly 2011, no significant difference. Of freshwater crayfish in normal circumstances, can not furnish to feed fish, fish. Although the shrimp can not grab fish swim faster, but it can feed on fish in the individual disability and death, but also the activities of zooplankton prey, algae and drifting plants.
habits (1) habitat as freshwater crayfish inhabit lakes, rills, reservoirs, morasses, reservoirs and trenches, and periodically also base in rice fields. But the edible is extra profuse in the hydrostatic ditches, reservoirs and superficial lakes are more type factories, mostly taint habitat, primarily humus more mire, more aquatic plants, roots or stones invisible objects. Habitat is more settled water class. The distribution of the shrimp more.
(2) for the nocturnal habits of animals, freshwater crayfish, benthic crawling camp life. Always prowling in the water during the day and low light bottom turn stones afterward to the grass or grotto in, night out feeding. In natural circumstances, because of absence of lure and lower water lucidity during the day and also reflected in its food. The shrimp have a strong climbing ability and migratory ability of oxygen in the water, lack of lure, pollution and other biological, physical and chemical ingredients of sudden casualty of strong changes in the case of embarrassment, often climb out of the water into variant water body. As rain, especially when it rains, the shrimp often climb out of the water in vitro play, migration from one water body to distinct body of water. Hi the shrimp against the new, often against the new traced back upwards against the new capacity and strong, the 20th centenary, 90 years, people in the Han River beneath the dike reservoir upstream and Dan found the shrimp. Now the shrimp in the upper reaches of the Jialing River Longnan City, Gansu Province, a Bailongjiang a natural distribution, it all illustrates this point. This is the shrimp in the afterward ponderous rain often climb out of ponds with water an of the reasons. Freshwater crayfish burrowing ability, in the lack of stones,GHD MK4 Gold Straighteners, weeds and caves for hiding a body of water, often in the embankment at the shrimp burrows. The depth of the cave, to the fluctuation of water level and water, soil and the embankment of the shrimp's life cycle. A significant rebate in the water level in water and the breeding of crayfish, which burrow deep; stable in water crayfish in the water and winter, the shallow burrow; in the growing season, about no freshwater burrowing crayfish . We fathomed the crayfish in the grotto, the longest up to 100 cm in diameter and up to 9.2 cm. Experimental observations show that the use of artificial freshwater crayfish to the existing body of caves and water chasms and other hidden objects, their burrowing behavior often watched in the breeding season, accordingly increasing the suitable place in the breeding pool, artificial lairs, and technical measures can be greatly depress the ridge of the shrimp pond, embankment break.
(3) the ecological requirements of freshwater crayfish is widely distributed in assorted types of water bodies, especially in still water canals, lakes and ponds in the more shallow, indicating that the shrimp eutrophication and hypoxia has strong adaptability. General water dissolved oxygen maintained at 3 mg / l or more, you tin encounter their growth needs. When oxygen is insufficient water, the shrimp constantly climbing apt the water surface at manner of water breathing or weeds, tree branches, stones and additional objects, will be deflected to the side of the cricket body crater at the surface of the water breathing, and even ascended up the land with oxygen in the air to breathe. In the dark, moist environment conditions, the physical survival of shrimp out of water more than a week.
freshwater crayfish on the high-temperature or low temperature has a strong adaptability, which with its geographic distribution along the tropical, subtropical and moderate regions are the same. The range of temperature adaptedness O ~ 37 ℃, in the Yangtze River basin, the winter night appearance their place with water, was frozen to live still survived, but the optimum temperature range of shrimp 18 ~ 31 ℃. Hatching and larval development of the water temperature at 24 ~ 28 ℃ for good. Freshwater crayfish of the heavy metals, some pesticides, such as trichlorfon and pyrethroid insecticides are very emotional to mores water ought meet water quality standards promulgated by the fisheries and water quality standards for pollution-free food. Such as freshwater crayfish farming with groundwater, the groundwater must be tested in advance to dodge heavy metals is affected by high growth and development of crayfish.

morphology (1) the external morphology of freshwater crayfish, freshwater crayfish, the whole body from head chest and abdomen, a total of 20 components, in addition to the tail partition there are no external appendages appendage 19 on the body surface with a hard carapace . 5 of the shrimp head, chest, 8, head and breast healing as a whole, called the cephalothorax. Cylinder head and thorax, front-end with a jaw angle triangle. Jaw angle of the surface of the central depression, either sides of the ridge, cutting-edge keen spines. Curved carapace with a pre-central sulcus, on either sides with coarse particles. Abdominal total of 7, the back has a smooth tail section, the appendages of the sixth abdominal section attach form the tail flare. 5 pairs of pereiopods, the first of the claws were like, gross. Second and third on the clamp-like, after the two pairs of claw-like. Gastropods, 6 pairs, the first female gastropods degradation of the male before the gastropods evolved into two pairs of calcium transfer apparatus. Each of the appendages with their respective functions. ######ually mature individuals of freshwater crayfish dark red or dark red, immature individual light brown, brown, red-brown range, and sometimes see the blue. Common individual full length 4.0 to 12.0 cm, the world's largest individual collected for the full-length 16.0 cm, originated in Africa, Kenya (JVHuner, 1984). We collected the largest in Hubei individual male full-length 14.2 cm, weight 101.70 g; female full-length 15.3 cm and weighs 119.19 grams. The length of a weight measurement obtained regression equation logW =- 0.3262 +3.0827 logL (L in the formula for the OCL, the orbital base to the posterior margin of carapace length in cm; W is weight in grams.)
(2) the inner structure of freshwater crayfish, freshwater crayfish are Arthropoda, the body without the backbone, the all body into the digestive system, respiratory system, circulatory system, excretory system, nervous system, reproductive system, brawn activity system, eight most of the endocrine system.

freshwater crayfish digestive system digestive system, including jaws, esophagus, tolerate, intestines, liver pancreas, rectum, anus. Mouth open in between the two stars, followed by the esophagus. Esophagus is a short tube, after the end stomach. Select the door into the stomach and the stomach pyloric stomach, the stomach duty on the door of the stomach composed of calcareous teeth grinding stomach, pyloric stomach wall, there are many bristles. Weinang, the stomach outside each side of a pearly or light yellow, semi-circular, button-shaped calcium terrazzo, pre-molting and molting of the large shell of the smaller chambers, calcium plays a regulatory role. The intestine after the stomach and intestine of the front on each side of the branch like a yellow liver and pancreas, liver and pancreas with liver and intestinal bamboo interlinked. After the intestinal segment slim, situated in the back of the abdomen, the spherical end of the rectum through the anus, anal opening in the tail section of the belly.
freshwater crayfish respiratory system respiratory system consists of the gill, a total of 17 pairs of gills in the gill cavity. 7 of coarse gill, and two pairs of teeth after the five couples of thoracic feet, thighs and the pedestal connected to the gills for the three prism, each prism arrangement of numerous of the small dense gill filaments. 10 on the gills of other small, skinny page, the walls is joined with the gills. Freshwater crayfish breathing, jaw ample to stream into the gill cavity incited, flow via the gills to complete gas interchange.
freshwater crayfish circulatory system circulatory system including the center, blood and blood containers, is an open-tube cycle. The back of the head and chest cardiac pericardial sinus is translucent, polygonal mighty sac, there are three holes on the heart, the heart to prevent blood backflow hole oscillate. Small blood vessels, and perspicuous. From the heart artery before the line has 5, the heart underwent abdominal artery with 1, down a thoracic artery from the heart 2. Both body liquids of blood for a perspicuous, non-red fluid.
drainage system in the pate inside the base of a large antenna with a pair of green glands, glands bladder after a hazy, leading to a large antenna from the base of the drain tube and openings in the body.
freshwater crayfish nervous system, the nervous system including ganglia, nerve and nerve rope. Ganglia are brain sections, such as esophageal ganglion, nerve ganglion is chained toward the body. Modern research confirms that freshwater crayfish of the neural stem and ganglion can excrete a diversity of neural hormones, these hormones play a regulation of nerve growth of freshwater crayfish, the process of molting and reproductive physiology.
reproductive system of freshwater crayfish dioecious, the male reproductive system, including 1 on testis, vas deferens and in 1 on 1 the base of the fifth pereiopods of reproductive conflict. The female reproductive system,GHD NZ, including 1 on ovarian, fallopian tube 1 on the fallopian tubes guiding to the base of the third pair of thoracic feet gonopore. Crayfish male and female crayfish transmit of control of the seminal vesicle does not fashion part of the reproductive system, but in the freshwater crayfish in the reproductive process plays a very major role.
freshwater crayfish muscle movement system muscle discipline system is composed of muscle and crustacean, crustaceans also understood as the exoskeleton, plays a supporting role in muscle function affecting the movement of the next play.
endocrine system is in a lot of information there is no say of freshwater crayfish with the endocrine system, but in fact is the existence of freshwater crayfish of the endocrine system, but many of its endocrine glands are often combined with other structures. As mentioned upon, combined with the thinking ganglion cells can synthesize and secrete neurohormones; there are freshwater crayfish eyestalk, modern research has proved that crayfish molt can taboo the secretion of growth hormone secretion and gonadal cells, secrete species of freshwater crayfish molt and the regulation of gonadal development of the hormone; there is a small lobster mandibular, modern research has proven to be a chemical synthesis of a Ji Fani vinegar (MF), the substance also plays regulation of freshwater crayfish sperm, egg protein synthesis and gonadal development.

category and distribution of freshwater crayfish, the Chinese phoned
scientific name Procambarus shrimp (procambarus clarkii), member in the animal taxonomy Arthropoda (Arthropoda), crustaceans (Crustacea), Decapoda (Decapkda), La cushions Branch (Cambaridae), is a sometime crayfish (Procambarus). It is a small freshwater crayfish in individual shrimp, national to North America, now widely distributed in more than 30 countries in five continents and zones. This is not the shrimp distribution in Africa, deserving to market claim in Europe and America, West Africa,GHD Green Butterfly 2011, Kenya, 70 in the 20th century after the presentation of culturing from North America, 80 in the early 20th century European freshwater crayfish to become a major supplier of one. The shrimp in the 20th century, 30 years into China from Japan, initially in the northern part of Jiangsu Province, with the expansion of natural populations and the breeding of person activities, the shrimp are widely distributed in China's Xinjiang, Gansu, Ningxia, Inner Mongolia, Shanxi, Shaanxi , Henan, Hebei, Tianjin, Beijing, Liaoning, Shandong, Jiangsu, Shanghai, Anhui, Zhejiang, Jiangxi, Hunan, Hubei,GHD Blue Butterfly 2011, Chongqing, Sichuan, Guizhou, Yunnan, Guangxi, Guangdong, Fujian and Taiwan, more than 20 provinces, municipalities, autonomous zones, and the formation of natural populations can be utilized. Especially in the Yangtze navel and lower reaches of the biological populations of large freshwater crayfish in China's main producing areas.




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savory freshwater crayfish farming is not easy to keep
magnetic slogan: Feeding is simple, a huge market; special concern space of ​​new violence in the manufacture; a person can be heaved more than 20 acres, maximum export good alternative. Past and Present

grams of the original's crawfish crab shrimp scientific name, also called ruddy freshwater crab, shrimp or crayfish. Native to North America. During World War II crayfish introduced into China from Japan, began in Nanjing, Jiangsu Province and the proliferation of suburban field. Now widely distributed in the provinces of the Yangtze River. At present, all wild crawfish crayfish.
lakes feeding rumors
technology
simple, regardless of ponds, paddy fields, lakes, rivers, braided outlet and some fish can no thrive in water or brackish water can be kept. Temperature using the usage set to shed match to lay eggs.
put 100 kg per mu profit
species of shrimp, a group of shrimp produced every three months, to produce before the next batch of shrimp fishing on the bargain of a group of adult shrimp, this coiling of the forgery cycle an annual output of up to 6,000 pounds, and one species, 3 --- 4 years to vote no longer buy types running. Analysis of allocation is 100 kg per mu in full the economic benefits of shrimp. Reference to minimum standards, the annual gross profit per acre: 6800 kg × 4 yuan / kg = 27,200 yuan / mu, the gross profit minus the cost of the year 6000 shrimp per mu can be more than 2 million annual profit. the true face of Lushan

natural water deficient
Nanjing Agricultural University, crayfish aquaculture specialist Tang Tiande truth that harder to raise than the crab. No one really large-scale breeding crayfish. Because crayfish in captivity requires a very high water quality, water quality requirements of pH amounts ​​between 6.8 to 7.5 in neutral, the oxygen content in the 3 mg / L or more. China Jiangsu part of the river basin in addition to meet the requirements, the repose are very difficult to meet the requirements.

crayfish crayfish combative behavior. Less than in the diets, investment patronize high density, needy water quality especially favor annihilating every other while the outcome crayfish survival is not high. At the same period is difficult because crayfish ovulation, a female can produce 100 crawfish shrimp eggs, and more will yield 200-300 only, and nigh the larvae grow more hello opposition the mother, do not like free, and the temperature of a cold, began burrowing crayfish hibernation, larval mortality is very high. These are the artificial rearing technology can not solve the problem.
profit
production of crawfish pond generally at 300 kg / mu, high energy to the five or 6 hundred pounds per acre, merely aboard this basis will be very laborious to cultivate yield. Crayfish in captivity can be said that if the per-mu yield of fewer than 5,000 pounds, is Kuibenmaimai, and existing technology can merely approach 500 kg / mu. The largest output of crayfish have a lot of folk in Jiangsu XUYI artificial feeding, the results of the premier three annuals merely 0.3% rate of return, there is not hundred to thousand complicated to maintain.
Summary
the small investors is still very difficult to become a direction to obtain wealthy quickly, after 2-3 years is anticipated to be difficult reserving a breakthrough technology. If you can, especially from abroad in North America to introduce first-class breeding technology, its hereafter is still bright.