China lobster

China lobster is also called prawn, dragon head shrimp, shrimp head and sea shrimp. Its head and chest are thick, its shell is hard, its color is rich and colorful, its abdomen is short, its body length is generally between 20 cm and 40 cm, and its weight is about 05 kg. It is the largest kind of shrimp. Shape: The body length is 200 ~ 300mm, the head and chest are slightly cylindrical, the abdomen is flat, and the tail fan is soft and translucent.

China lobster is also called prawn, dragon head shrimp, shrimp head and sea shrimp. Its head and chest are thick, its shell is hard, its color is colorful, its abdomen is short, its body length is generally between 20 cm and 40 cm, and its weight is about 0.5 kg. It is the largest kind of shrimp. Shape: The body length is 200 ~ 300mm, the head and chest are slightly cylindrical, the abdomen is flat, and the tail fan is soft and translucent. The heaviest can reach more than 5 kilograms, and it is called lobster tiger. The body is thick and cylindrical, the back and abdomen are slightly flat, the head and breastplate are developed, thick and prickly, there are a pair of powerful supraocular spines in the center of the front edge, and there is a closed gill chamber. Mainly distributed in tropical waters, it is a precious seafood. Eight species have been found in China, among which freshwater lobster has a large output. It is mainly produced in the South China Sea of China, the Southeast China Sea of China and the coastal areas of Taiwan Province Province. It lives in shallow water with a water depth of 40-70 meters, mostly inhabiting rocks and rocks. The famous lobster is produced in Xuyi, Jiangsu. China lobsters are generally smaller than imported lobsters.

Growth characteristics

After molting, the new crustacean completely hardens, which is the continuation of the molting growth process of China lobster and is of great significance to the normal and rapid growth of China lobster. Environmental factors and nutritional conditions have significant effects on molting and growth of China lobster. 24 ~ 27℃ is the suitable temperature range for molting growth of China lobster. The salinity of 24 ~ 32 is suitable for the growth of China lobster, and the optimum salinity is 28; Among the six experimental feeds, China lobster was fed with Mytilus viridis, followed by mixed shrimp, mixed crab and oyster. The molting growth rate and stage growth rate of China lobster fed with mixed fish were very low. Adding molting hormone to lobster feed can shorten molting cycle and realize synchronous growth of molting rate and molting growth rate. Removing the eyestalk can also promote the molting and growth of China lobster, while external stimuli such as electrical stimulation can only promote the molting of China lobster, but not accelerate the growth of China lobster, and may even have negative effects. There are intra-species gender differences in the growth of China lobster, and the molting growth rate of male individuals is higher than that of female individuals under the same conditions.

Appearance characteristics

China lobster has a slightly cylindrical head and chest, a flat abdomen and a soft and translucent tail fan. The surface of the head and breastplate is covered with soft hair and strong thorns. In addition to the upper corner of the eye, there are four large spines in the front edge, but the frontal angle is missing. The upper forehead plate is healed with the head and breastplate, and there are 2 pairs of separate main spines and many spines. The second to sixth abdominal segments have sunken soft hair areas, especially the second and third abdominal segments. The front edge of the lateral carapace is smooth, but there are teeth at the base of the rear edge of the second to fifth abdominal carapace. The first antenna whip is 2, which is short, and the second antenna whip is 1, which is thick and long, and the length is similar to the body length. The five pairs of walking feet are stout, except that the end of the fifth step foot of the female is half-pincer-shaped, and the rest are claw-shaped, with claw-free pincer structure. There are only four pairs of swimming feet, which are thin and soft. Males have one limb and females have two limbs, which are more developed than males, and many bristles are attached to them, which is beneficial to egg attachment.

The body surface of China lobster is turquoise. There is no bright stripe in the center between the front edge of the head breastplate and the two eye stalks. The eyes are dark brown, with brown and yellow stripes on the upper corner of the eye, and yellow and white stripes on the feet. There are small white spots scattered in the abdomen, and the white spots at the joints are larger. Abdominal limbs are reddish brown.

The appearance and body color of China lobster are very similar to that of corrugated lobster, but there are no bright orange and blue stripes between the eyestalks of China lobster, and their feet are striped rather than spotted, which makes them easy to distinguish. Adult shrimp is about 20 ~ 40 cm long and weighs about 0.5 kg, and the largest shrimp can reach 3 ~ 4 kg.

Living habits

China lobsters live in the sea area 7-40 meters deep off the southeast coast of China, and inhabit among rocks. For example, there are few lobsters in Zhouxiao Island in Zhanjiang, and there are plenty of China lobsters in the sand bottom in the north and the rock bottom in the south. Lobsters in China are carnivorous and have a wide range of feeding habits. All fish, crustaceans, shellfish with thin shells that can be caught, living or dead and not rotting, are their food. China lobster, which is temporarily raised, likes duck-billed shellfish best. Lobsters in China have underdeveloped swimming feet and strong chest feet, so they can only crawl for food, and generally feed on benthos. It has a large appetite and can eat115 of its own weight at a time. It is also quite hungry, and it will not starve to death if it is not fed for a week.

living environment

China lobsters are naturally timid. Under natural conditions, they lie down during the day and come out at night. They hide in caves on rocks during the day and move and eat at night. When digging a hole, the tail rolls up and retreats into the hole, and the two tentacles stay outside the hole for circular motion. Lobsters in China like to live underwater. They live in groups. People often find many lobsters living in the same cave. When digging a hole, China lobster has no strict choice about the texture of the hole. Caves, mud pipes, bamboo tubes and plastic pipes are all applicable, but China lobsters are selective about the shape, size and direction of caves. When circular caves and polygonal caves exist at the same time, China lobsters first choose angular irregular caves to inhabit; In the case of caves with different sizes, China lobsters choose tight caves that are easy to find and rely on. Although China lobsters can inhabit in vertical caves, their inhabitation rate is lower than that in horizontal caves. If China lobsters inhabit spacious caves, they usually hang upside down by grabbing the cave walls with their feet.

Artificial culture of lobster can be matched with pond culture and cage culture, and combined with intensive culture and temporary culture. In the sea area where the artificial lobster culture pond is located, the annual water body proportion should be1.018 ~1.023, the pH value is 8.0, the water temperature is 18 ~ 32℃, the transparency is greater than10m, and there are no pollution sources and river forks in the surrounding coastal zone. A cage is arranged outside the pool for temporary support.

Mytilus viridis has the best feeding effect on China lobster, followed by mixed shrimp, mixed crab and oyster. Although the growth rate of China lobsters fed with compound feed is high, the molting cycle is long, which indicates that the nutritional effect of feed is not bad, and the low feeding rate may be the main reason for the long molting cycle of China lobsters. The molting growth rate and stage growth rate of China lobster fed with miscellaneous fish are very low, which reflects the nutritional defect of miscellaneous fish as bait for China lobster.

China lobsters inhabit the warmer shallow sea, with a water depth of 40-70 meters, which is more than reef cracks and rock piles. Although they also appear in shallow water, they most often live in deep water. Larvae usually inhabit a rocky environment with a water depth of 0-4 meters, surrounded by dense plants.

sexism

There are differences between male lobsters and female lobsters, which can be identified mainly by the following methods:

China lobster is hermaphrodite, hermaphrodite and has obvious sexual characteristics. The reproductive foramen of male shrimp is located on the reproductive process at the base of the fifth step foot, and the end of the fifth step foot is claw-shaped, and the swimming foot has one limb and no inner limb, which is underdeveloped. The reproductive pore of female shrimp is located at the base of the third step foot, and the end of the fifth step foot is semi-pincer-shaped, with bipedal swimming feet and feathery bristles, which is more developed than that of male shrimp.

1, parent shrimp of the same age, the female shrimp is bigger than the male shrimp;

2. For the parent shrimps with similar body length, the male claw is thicker than the female, and the spinous processes on the male claw wrist joint and metacarpal joint are long and obvious;

3. Female shrimp 1 has degenerated and small abdominal limbs, and the second abdominal limb is normal. The 1 and 2 abdominal limbs of male shrimp become tubular, long and reddish, and the third, fourth and fifth abdominal limbs are white, which is the most obvious difference between male and female shrimp in appearance.

sexual maturity

Lobsters reach sexual maturity at the age of 6- 12 months in the natural environment, and the weight of individuals who reach sexual maturity is generally 30-100g. Under the condition of artificial feeding, accessibility is generally mature in about 6 months. Parent shrimp of the same age, generally male shrimp is slightly larger than female shrimp. The sex ratio of lobsters raised in the same pond is close to 1: 1.

breeding method

The spawning period of lobsters in China is from March to September, and the hatching rate is the highest in July and August. In the breeding season, China lobsters migrate from the habitat waters of about 40m to the shallow waters of 7- 10m, spawn and hatch in the shallow waters, and then migrate to the deep waters for molting. When the breastplates of China lobsters grow to 50-60mm, they can be sexually mature. The female lobster holds as many as 65,438+10-300,000 eggs at a time, weighing 250-300 g. The females mate within one month before spawning, and the males ejaculate on the female chest plate, and the females immediately secrete jelly to wrap the sperm to form a sperm bag. When laying eggs, the sperm is stimulated by estrogen and released, completing fertilization and forming fertilized eggs. The color of the newly born egg is bright orange. With the continuous development of the embryo, the color of the egg mass gradually changes from deep to light, and the yolk in the egg has been consumed in the later stage of embryo development, and the egg color is light and almost transparent. Under the conditions of water temperature of 25℃-30℃ and salinity of 28℃-33℃, the embryonic development process lasted about 65438 06-20 days.

1. Oviposition: Lobster is a type that spawns many times a year. When the water temperature rises above 20℃, the parent shrimps begin to lay eggs. The spawning period in eastern Guangdong can be as long as 6 months, and it can spawn 3-4 times a year. The amount of eggs laid varies with individual size and gonad development, generally 300- 1000 eggs each time. Larger females have more eggs.

2. Embryonic development: The fertilized eggs of lobsters attach to the abdominal limbs of females for embryonic development, and larvae hatch after 5-8 weeks. The development speed of fertilized eggs is related to the water temperature, and the incubation time is short at high temperature. The initial egg diameter of a fertilized egg is 2mm. With the development of the embryo, the color of the fertilized egg changes regularly at different stages of development, from light milky white at the initial delivery to dark brown with black eye spots, and finally turns orange. At this point, the larvae are about to hatch. When the water temperature is 32℃, the above colors appear in turn during the development of fertilized eggs: light milky white 1-5 days; Dark brown 12- 14 days; Eye point appears for 20-33 days; Orange for 28-35 days; Break the membrane and leave the mother for 35-40 days.

3. Larval development: molting is an important physiological phenomenon of crustaceans. China lobsters molt about 3-4 times a year, and individual lobsters molt more frequently than big lobsters. China lobsters stop eating 3-4 weeks before molting, and hide in caves or other secluded places, waiting for the opportunity to molt. At the beginning of molting activity, the continuous part between the crustaceans of the head, chest and abdomen first splits, and then the software breaks free from it. The whole molting process lasts 30-60 minutes. In case of disturbance during molting of China lobster, molting can be temporarily stopped and resumed when it is on standby, which can also be successfully completed. 7~ 10 day after molting, the carapace of China lobster gradually hardened and resumed feeding.

distribution range

China lobster is an endemic species in China waters, mainly distributed in South China Sea of China, South East China Sea of China and coastal areas of Taiwan Province Province. Crayfish belongs to Arthropoda, Crustacea and Procambarus in animal taxonomy. Also known as crayfish, Procambarus clarkii or freshwater crayfish, it belongs to small and medium-sized freshwater crayfish species.

Lobster, native to North America, is an important species of freshwater shrimp culture in the United States. 19 18 years, Japan introduced crayfish from the United States as bait for bullfrogs, which proliferated in Japan on a large scale. During World War II, crayfish was introduced into China from Japan on 1938.

In China, crayfish first proliferated in Nanjing and suburban counties of Jiangsu Province. With the expansion of natural population and the development of human breeding activities, crayfish are now widely distributed in Xinjiang, Gansu, Ningxia, Inner Mongolia, Shanxi, Shaanxi, Henan, Hebei, Tianjin, Beijing, Liaoning, Shandong, Jiangsu, Shanghai, Anhui, Zhejiang, Jiangxi, Hunan, Hubei, Chongqing, Sichuan, Guizhou and other places. There are many biological populations in the middle and lower reaches of the Yangtze River.

economic value

Lobster is an important marine fishery object in China, with the largest quantity, the widest distribution and the largest output. China lobster has high economic value because of its big size, delicious taste, rich nutrition and high market price, and China lobster has a high therapeutic effect. The meat is sweet and salty, tender and refreshing, warm in nature, and has the effect of nourishing yin and tonifying kidney. This is a precious seafood. China's coastal areas are rich all year round and should be built in June and July of the lunar calendar. Smaller than Australian lobster, but more than twice as expensive, because the shell is thin, the meat is cool and sweet, and the taste is fragrant, which is better than other lobsters. Mother shrimp is especially creamy. There is a strong demand in the lobster market, and the price has been rising all the way. The domestic price of live lobster is as high as 300~500 yuan/kg. It is reported that China began to consume a large number of seafood lobsters in the 1990s, and the total amount of imported live lobsters in Shanghai, Beijing, Guangzhou and other cities alone was not less than 1.5 million tons. [3] It has become a very important ingredient in China's diet. Lobster streets have been built in many places in China to bring together restaurants that operate lobster business. When there are many people, you need to queue up for the number to eat. This shows the popularity of lobster in China.

nutritive value

1, rich in protein, can maintain the balance of potassium and sodium; Eliminate edema and improve immunity. Lowering blood pressure and buffering anemia are beneficial to growth and development.

2, other effects: easy to digest, it is an excellent food for people who are weak and need to be nursed back to health after illness; It plays an important role in regulating heart activity, protecting cardiovascular system, reducing cholesterol content in blood, preventing arteriosclerosis and dilating coronary artery, and is beneficial to preventing hypertension and myocardial infarction. Shrimp has a strong breast enhancement effect and is rich in phosphorus and calcium, which is especially beneficial to children and pregnant women.

3. Nutritional components: per100g edible part, it contains 76.00g of water, 9.37g of protein/kloc-0, 0.60g of fat/kloc-0, 0.70g of carbohydrate, 0.8g of ash1.. Vitamin B 1 10 μ g, B2 100 μ g, nicotinic acid 1.9 mg, and arginine, histidine, lysine, alanine, cholesterol, carotene, etc.

4, suitable for all ages, middle-aged and elderly people, pregnant women and cardiovascular patients are more suitable for eating. It is suitable for people with emaciation, low immunity, hypomnesis, anemia, edema and other symptoms, as well as children with stagnant growth and development. It is suitable for people with kidney deficiency, impotence, male infertility and weakness of waist and legs, and is suitable for middle-aged and elderly people with calf cramps caused by calcium deficiency. But lobster is a hair growth product, and patients with allergies or heat syndrome had better not eat it.

Medicinal value

Harvest spring fishing.

After processing and catching, remove the shell and take the meat, and use it fresh or dry it in the sun for later use.

Has the effects of tonifying kidney, strengthening yang, nourishing yin and stomach, and calming the nerves.

Indications: impotence, neurasthenia, muscle pain, tetany, skin itching, head sore, scabies and other symptoms.

breeding technology

1, pond conditions

① Adequate water source, good water quality and convenient irrigation and drainage, covering an area of 3-5 mu.

(2) The embankment has a certain slope and width to prevent crayfish from escaping by digging holes, and an escape wall with a smooth inner wall of 0.5m is set around the embankment.

③ Build some mud ridges in the middle of the pond to create holes for crayfish. The two ends of the mud ridge are not connected with the pond ridge. The length of the mud ridge is about 4/5 of the length of the pond, the width is greater than 1 m, and it is 5 5- 10/0cm higher than the water surface.

(4) Before stocking, 75 kilograms of quicklime per mu should be thoroughly disinfected. After the toxicity disappears, 500-800 kilograms of decomposed livestock manure should be applied per mu to improve the water quality.

⑤ Screen should be used to filter the incoming water to prevent pests from entering. The water depth of the pool is 0.8- 1.5m, the middle is deep and the periphery is shallow, and roots and bamboo tubes are placed at the bottom of the pool. Some aquatic plants, such as Sophora alopecuroides, black algae, Eichhornia crassipes, Eichhornia crassipes and Alternanthera philoxeroides, are planted in the pond, accounting for about 30% of the pond area, which is convenient for crayfish to avoid enemy attacks and habitats when molting.

Step 2 raise shrimps

Shrimp species should have strong physique, complete appendages, no injury or disease, strong activity, and the stocking specifications in the same pond should be consistent, and all of them should be stocked at one time. Before stocking, put the shrimp seeds into a plastic basin, slowly add a small amount of pool water into the basin until the water temperature in the basin is close to that of the pool water, then soak them in 3%-4% salt water for disinfection 10 minute, and then slowly put the shrimp seeds into the basin along the edge of the pool.

(1) Summer stocking: mainly young shrimps artificially propagated in that year are stocked in the middle and late July, and 30,000-40,000 young shrimps with the size of 0.8 cm or more are released per mu.

(2) Stocking in autumn: the large shrimp species cultured in that year are the main species, and the stocking time is from August to September, with 25,000-30,000 per mu with the specification of 1.2 cm and 2.5-3 cm per mu1.5-20,000.

(3) Stocking in winter: the shrimps that do not meet the market specifications of the current year are mainly stocked, generally in June 5438+ February or March-April of the following year, and each acre of shrimp ditch is stocked 1000- 15000 shrimps by about 3 cm.

3. Feed feeding: minced fish, snail meat, silkworm chrysalis, earthworm, leftover from slaughterhouse, rice bran, bean cake, bran, pumpkin, sweet potato and fresh aquatic plants can be fed directly, and compound feed for shrimp can also be fed, but the crude protein content in the feed should be kept above 25%. The water temperature in July is suitable-10, indicating the growth season of shrimp. At this time, the daily feeding amount is based on the satiety of shrimp, and no residual bait is left after eating. General animal feed accounts for 8%- 12% of shrimp's weight, and dry feed or compound feed accounts for 3%-5% of shrimp's weight. Feed is put in the shallow water near the pool, twice a day, morning and evening 1 time, and the feeding amount is 60%-0% at night. In other seasons, shrimp is fed 1 time every day, and the daily feeding amount is about 2%-2% of the shrimp's weight before and after sunset. Lobsters have poor swimming ability, small range of activities and occupation habits, so they should be fed regularly, regularly, qualitatively and quantitatively. In addition, feed feeding should pay attention to sunny days, sultry, continuous rainy days or when the water quality is too strong; A large number of shrimps throw less when molting, and more after molting.

4. Daily management: insist on patrolling the pond every day, and handle problems in time when found. Timely topdressing: after the shrimp fry are stocked 1 week, 50-60 kg of decomposed livestock manure should be applied per mu, and 15-0 kg of decomposed manure should be applied every half month in the middle and late period of culture to keep the green or brown beans in the pond, and the transparency is about 35 cm. Change the water frequently. Change the water 1 time every 5-7 days in hot season, and change the water 1 time every 5-20 days in normal times. The amount of water changed each time is 20%-30% of the pool water. Keep the pH value of the pool water at 7-9, and the dissolved oxygen is greater than 4 mg/L. Disinfect and improve the water body regularly, sprinkle10-15 kg of water every/kloc-5 days, sprinkle 0.5-0.6 g of bleaching powder or disinfectant every cubic meter of water every month, and use photosynthetic bacteria 5 per cubic meter of water every month in the middle and late stages of culture.

5. Fishing on the market: Lobsters grow rapidly. After 3-5 months' feeding, when the adult shrimp reaches more than 30g, it can be caught and marketed. There are many ways to catch fish, such as shrimp cages, casting nets, pulling nets or fishing in dry ponds. Fishing adopts the method of catching big fish and keeping small fish, and those who fail to meet the market specifications continue to stay in the pond for breeding.

China lobster festival

China Lobster Festival is jointly organized by Xuyi County People's Government and Yangzi Evening News Agency.