Australian freshwater lobster, refers to Australia and the surrounding areas of freshwater crayfish. Although there are more than 100 species, and at present in Australia has been large-scale farming and began to export foreign exchange earnings of the main slippery stingray genus ( Cherax ) three kinds. The first is the Maron crayfish (English Maron, scientific name C. tenuimanus ), some people translated as Maron crayfish or Myron crayfish; the second is the teeth don't crayfish (English Yabbie, scientific name C. destructor ), there are some people translated as Yabbie crayfish; the third is the red chelid crayfish (English Red Claw, scientific name C. quadricarinatus) The third is the red crayfish (Red Claw, scientific name C. quadricarinatus), which has also been translated as the four-ridged crayfish. Therefore, the general aquaculture now known as the Australian freshwater lobster, is the commercialization of the above three types of crayfish.

Basic introduction Chinese name: Australian freshwater lobster World: Animalia Door: Arthropoda Subphylum: Tongs Subphylum Chelicerata Outline: Crustacea Purpose: Decapoda Family: Parastacidae Genus: Crayfish Species: Crayfish, Crayfish, Crayfish, English name: Crayfish, Crayfish, Crayfish, Crayfish, English name: Crayfish, Crayfish, Crayfish, Crayfish: Crayfish Origin : Australia Introduction, biological characteristics, morphological features, ecological habits, geographical distribution, shrimp pond construction, breeding techniques, selection of shrimp, shrimp fry stocking, scientific baiting, shrimp pond management, timely harvesting, disease prevention and treatment, fishing and transportation, Introduction to the Australian freshwater lobster, originating in Australia. The shrimp in recent years by the introduction of trial breeding in Guangdong Province and has achieved success in artificial reproduction of seedlings and adult shrimp farming, is now being promoted in the province and outside the culture. Australia's freshwater lobster because of the individual large, and the appearance of some like the sea lobster, and only live in fresh water, so it is called freshwater lobster. Individuals generally weigh 100 to 200 grams, the largest individual in Australia can weigh up to 500 grams. According to research, the Australian freshwater lobster is currently one of the world's valuable economic shrimp species. Biological characteristics Morphological characteristics from the morphological structure, the red crayfish, teeth don't crayfish and the Malone Crayfish body surface are not obvious spines, internal and external parts of the naming is basically the same, all have the cephalothorax and abdomen. There were 20 body segments, 13 cephalothorax segments and 7 abdominal segments. Body surface covered with chitinous armor. Bimanual appendages. One pair of stinging limbs, which is also the first pair of stepping feet. The other four pairs of pedipalps are not as strong as the first pair. One pair of large tentacles and two pairs of small tentacles. On the abdomen there are four pairs of swimmer's feet, arising from the second to fifth abdominal segments. The caudal segment and the caudal foot of the sixth abdominal segment evolve into a caudal fan. The cephalothorax is externally covered with cephalothoracic armor, with the frontal sword anteriorly. Male shrimp in the fifth pair of footsteps at the base of a pair of genital protuberances, which asked the genital pore. Female shrimp in the third pair of footsteps at the base of 1 pair of reproductive holes, more obvious. The female shrimp is smaller than the male shrimp. Especially the red crayfish, female shrimp than male shrimp individual small 1/4 to 1/3, the three kinds of shrimp body color changes with the intensity of light has a great relationship, in the pool water fertility, transparency 30 to 50 cm, shrimp body color is more bright; in the pool water transparency is very deep, the light is very strong, shrimp body color is darker, leaning toward the brown. For example, the body color of the red crayfish, light normal blue-green, too much light can be changed to green-brown. Breeding in order to get bright body color. Be sure to control the transparency of the water. Australian freshwater lobster these three kinds of shrimp in the appearance of the more obvious difference is: the red crayfish body color is bluer, the chelipeds are longer and thinner. The male crayfish chelae are thicker than those of the female, and the outer edge has a bright red corneal membrane. This makes it easy to distinguish between males and females in terms of appearance. In addition, the red crayfish has four longitudinal ridges on the dorsal side of the cephalothorax carapace, two of which are located behind the frontal tip, and two of which are located in the postocular region. Therefore, some people call this shrimp a four-ridged crayfish. The body color of the crayfish is gray, and the shape of the chelipeds is short and thick, strong and powerful. The outer edge of the cheliped is more curved. The stinger is larger than the other two types of shrimp. Malone crayfish in the three largest, in the same weight compared to the other two shrimp, the claw belongs to medium-sized. Ecological habits Australian freshwater lobster gill respiration, dissolved oxygen conditions in the water body is very important for its growth and development and its food transformation and transformation of toxic substances in the water body. Although the red crayfish and the tooth don't Crayfish tolerate low oxygen, but when the dissolved oxygen in the water body reaches more than 4 mg / liter will be more conducive to improve the growth rate. Maroon Crayfish has a higher requirement for dissolved oxygen in the water. It is better to reach more than 7 mg/liter in culture to facilitate its growth. Red crayfish, teeth don't crayfish sexual maturity time to more than 6 months, marron crayfish sexual maturity to more than 10 months. If the conditions are suitable, all kinds of shrimp can carry eggs several times a year. Eggs are produced and attached to the abdomen. At this time the female parent shrimp is called to hold eggs shrimp. 1 time to hold the number of eggs according to the weight of female shrimp and nutritional conditions, generally from hundreds of grains to thousands of grains. 50 grams of female shrimp to hold the number of eggs of 300 to 600, 100 grams of female shrimp to hold the number of eggs of 600 to l,000 grains. Hold on to the eggs, regardless of the female shrimp activities or feeding, will use the swimming feet to fan the current to the egg oxygen supply and maintain constant conditions. When there is a disturbance, the parent female shrimp immediately use the tail roll to protect the egg mass, to avoid damage to the eggs. Hatching takes about 26 to 46 days. The water temperature should be controlled at 23 to 27°C for red and tooth don't crayfish and 19 to 23°C for marron crayfish. Female shrimp temperament than compared to the male shrimp to be a little more gentle, have the habit of protecting shrimp fry. Shrimp fry hatched, in 7 to 12 days has been in the female parent shrimp in the lower part of the egg shell of the abdominal life, at the same time protected by the female shrimp, a little strong before leaving the mother's independent activities. Red-crayfish, teeth don't crayfish from baby shrimp to commercial shrimp generally have to molt more than 20 times, Maroon crayfish to commercial shrimp to molt more than 30 times. Geographic distribution of the three species of Australian freshwater lobster in Australia distribution area is different, this is mainly due to the physiological and ecological habits of the respective decision. The crayfish was originally farmed mainly in western and southwestern Australia, and is now also farmed in the south, New South Wales and Queensland. The tooth don't crayfish is the most widely distributed and produced in Australia. Red crayfish farms are most numerous in Queensland, and because this state is in northern Australia, the warmer temperatures are well suited to the growth of this shrimp. In recent years, some shrimp farms in other regions have also increased or switched to red crayfish. Shrimp pond construction Australian freshwater lobster farm site selection, directly related to the column group sparkling good or bad and economic benefits. Selection should take into account the water, transportation, soil quality, vegetation, bait and other aspects of the specific situation, a comprehensive analysis of the pros and cons of all aspects before deciding to build the farm, drawing sketches, demonstration of modification, to decide the scale of investment and estimate the expected benefits. The main aspects of site selection are: (a) easy access to water, good water quality, sufficient water Australian freshwater lobster; (b) good soil shield structure, no water seepage, no harmful substances; (c) quiet environment, less harmful animals; (d) vegetation, bait and other conditions. The construction of the site can be divided into two parts. One part is the construction of adult shrimp (commercial shrimp) breeding ponds, and the other part is the construction of breeding ponds. Breeding technology Parental shrimp selection Parental shrimp is the basis of artificial breeding, should try to choose individual robust, smooth body surface, no disease, no injury and good nutritional status of adult shrimp as parental shrimp. Theoretically, the Australian freshwater lobster in the temperature, nutrition, water quality and other conditions are appropriate conditions, 1 year can be many times spawning, up to 4 times, but it depends on its physical ability to withstand. Parent shrimp with slightly poor body condition, although it can harbor eggs, but the eggs can not be well developed, but the development time is very long, affecting the number of spawning. Therefore, special attention should be paid to the selection of the parent shrimp. Selection, the red crayfish and teeth don't crayfish parent shrimp male-female ratio of 4 to 5: 1, Malone crayfish for 3 to 4: 1. If the male shrimp ratio is too large, because of its mobility, and sometimes have a negative impact on the female shrimp holding the eggs, and this ratio, the male shrimp has been enough. The best time to choose the shrimp is in the fall when the shrimp. At this time to facilitate the selection, after the selection into the pro-shrimp pool in the temporary wintering. Ensure that the shrimp nutrition, strengthen the daily management, pay attention to stocking density, and do a good job before spawning intensive cultivation. In the general pro shrimp temporary pool, the red crayfish and teeth don't crayfish pro shrimp stocking density should not be more than 5 / square meter, the number of Malone crayfish pro shrimp to 1 / square meter is appropriate. Manage the water quality well and check the shrimp regularly. Temperature control, red crayfish and dental crayfish egg incubation temperature should be maintained at about 25 ℃, Marron crayfish incubation temperature should be controlled at about 21 ℃, to maintain a high dissolved oxygen in the water, this time the hatching of the shrimp seedling physique strong, high survival rate, breeding growth and development is also fast. Shrimp seedling stocking Shrimp seedling stocking should be selected in the early morning or evening of sunny days. Before the release of seedlings with a small amount of pool water slowly added to the container to regulate the temperature of the water, until the temperature of the water in the container is close to the temperature of the pool water, and then put the shrimp seedlings into the pool, in order to prevent the shrimp seedlings "cold", affecting the survival rate and growth and development. Shrimp fry stocking specifications are generally 3 to 5 cm, stocking density of 5000 to 6000 tails per mu, such as shrimp fry is small, can increase the stocking amount, the same pond stocking of shrimp fry specifications require neat and consistent. Scientific baiting in the baby shrimp will hatch out before 10 to 15 days per mu shrimp pond put about 200 kg of rotting organic fertilizer, cultivate "rotifers" to ensure that shrimp fry stocked with sufficient palatable bait. Three days after the release of seedlings in the pond to red worms supplemented by stranded small mixed fish and minced meat-based; and then cast about 1 month of small mixed fish, leg meat and artificial feed; to be shrimp seedlings to grow to 6 ~ 7 cm, can be fed all the rolled snails, mussels and the appropriate amount of plant-based feeds. Daily feeding to eat full, eat up, do not leave residual bait shall prevail. General medium and small shrimp fed at 15% to 25% of body weight, adult shrimp fed at 5% to 10% of body weight. Every day, morning and evening feeding 1 time, the evening cast the whole day feeding 70% to 80%, the feed should be cast in shallow water. Shrimp pond management As the Australian freshwater lobster fast-growing, vigorous metabolism, oxygen consumption, shrimp pond water quality should be constantly kept fresh, generally 15 to 20 cm of water per week, the water quality to reach the live and fresh, and there is enough dissolved oxygen, pool water transparency control at about 35 cm. In day-to-day management should be diligent inspection, diligent pond inspection, timely removal of moss in the pool, often check the inlet and outlet filters, to prevent filter breakage after the shrimp escape and wild fish and other hostile organisms into, when encountered in thunderstorms and muggy days, cloudy days of inclement weather, to reduce or discontinue feeding, when the weather is too hot and too cold, should be appropriately deepen the pool water in order to stabilize the water temperature, and at the same time, but also frequent observation of the freshwater lobster feeding and activities Growth, shelling and so on. Timely harvest Australian freshwater lobster stocked that year, the year of harvest, generally can be grown to adult shrimp when using dry ponds or purse seine one-time fishing. If the phased listing, trawling or netting can be used to catch, but also the use of traps cage, that is, the cage put bait, luring shrimp into the shall not come back out. All fishing process should be completed before the water temperature drops to 5 ℃. Disease control The main enemies are rats, frogs, waterfowl, water centipedes, rocking mosquito larvae. To do a good job in a timely manner to eliminate rats, clear the pool frog eggs, tadpoles, in the pool around the shore net 30-40 cm, to prevent frogs, water snakes invasion. Water centipede found in the pool, can be captured by sea fishing. Disease control: Australian freshwater lobster disease resistance, since its introduction has not been found since the outbreak of epidemic diseases, but with the improvement of intensive aquaculture, disease control should not be taken lightly! Prevention and control work should be prevention-oriented, seedlings can be sterilized on the body surface before the pond, to prevent the pathogen brought into the pool. Several pathogens have been seen mainly parasites, algae and certain bacteria. When the water quality changes, more microorganisms in the water, the shrimp body cephalothorax, footsteps and other exoskeletons will be born on many yellow or brown attached organisms. Observed by microscopic examination, most of the ciliates of the tired branch worm, aggregated shrinkage worm, bell-shaped worm and so on. These ciliates are attached to the exoskeleton of the adult shrimp shrimp, camp *** life, the formation of rough body surface branches, warts, aggravate the burden and pressure on the host, resulting in slow action, reduced feeding, moulting difficulties, if the water is low in dissolved oxygen, it is easier to lead to hypoxia and asphyxiation, or even death. In this regard, the shrimp and crab ciliate net treatment. The dosage per acre is 500 grams per meter of water depth. If the killing is not complete, there is still a small amount of residual insects, can be used for the first time after seven days, according to the amount of this drug splash again. Preventive dosage is reduced by half, once a month. General parasites can be removed by splashing or hanging bags with copper sulfate and ferrous sulfate (5:2) 0.5-0.7PPM, or by washing with 15-25PPM formalin or saturated saline water. Gastrointestinal disease is mostly caused by the intake of spoiled bait, so the bait should be fresh and not moldy. When choosing legumes as bait, it must be treated with heat to remove the antitrypsin and favor the absorption of plant protein. Current disease control can refer to other shrimp disease control information. But it should be emphasized that shrimp species are different, and the sensitivity to various drugs is not the same. In borrowing other shrimp medication solubility must pay attention to observation, if uncomfortable to change a lot of water in time to avoid losses. Litter, young shrimp poor ability to tolerate harsh environments, so to improve its survival rate, it is best to keep the water temperature between 16-30 ℃. Although the Australian freshwater lobster can tolerate low oxygen, but a long time in a low-oxygen environment to survive, will reduce immunity affect feeding, shelling and growth. Therefore, in the breeding pool should also be equipped with oxygenation facilities. If you find a lack of oxygen, you should turn on the oxygenator in time to ensure that the water has sufficient dissolved oxygen. Australian freshwater lobster is more sensitive to pesticides, if there is the use of farmland water irrigation pool, in the farmland during the application of drugs should be strictly prohibited field water into the shrimp pond. Some people also blindly cast trichlorfon pesticide, intended to kill the enemy organisms and cause serious death of lobster accident. Fishing and transportation Australian freshwater lobster is generally in the breeding 160-180 days, each can reach 75-200 grams (more than 50 grams can be marketed). Fishing methods are: 1. Shrimp cage trapping: put the trap cage in the evening, the cage is appropriate to put some bait, early in the morning to collect the cage, or several times at night to collect the cage, this method is convenient and easy to operate, to facilitate the successive provision of live shrimp to the market. 2. Catch against the water: freshwater lobster has a strong countercurrent, in the catch before the pool water discharged 30%, the evening into the new water, in the water at the end of the roundup. Three consecutive times, the capture rate can reach 70%. 3. Clear the pond to catch: stock pond shrimp is not much, you can drain the pond water, catching clean. Australian freshwater lobster, its dry ability, second only to crabs. Facilitate the long-distance transportation of live shrimp, transport a large number or long transport distance, then wicker or bamboo scorn preparation of baskets and boxes or perforated foam boxes for shipment on all sides. Before transporting the shrimp rinsed, clamped, each box can be put 10-15 kilograms. The upper part of a small amount of water plants, with wire clamp tight box lid. Sprinkle a small amount of clean fresh water on the way, so that the commercial shrimp in the box to keep wet. Attention to light shipping, when the temperature does not exceed 28 ℃, within 24 hours of transportation survival rate of 100%, commercial shrimp transported, it is necessary to put the freshwater lobster scattered in cement or frozen vat or 8-10 ℃ refrigerated tanks, and drenching to maintain moisture, do not concentrate on a large number of lobsters in static water containers to avoid overdensity, the lack of oxygen in the water suffocated to death.