Yellow-finned snapper, scientific name: Acanthopagrus latus (Houttuyn, 1782), sparuslatus (commonly known as Chaoshan), also known as yellow-footed fish, red-winged fish and yellow-fingered fish. A marine fish belonging to the genus Echinoceros of Sparidae. With strong adaptability and fast growth, it is an important object of cage culture in southern China. Yellow-finned snapper is oval in length, flat on its side, narrow on its back and blunt and round on its ventral surface. Tall, with a pointed head. The spines of dorsal fins are connected with fins. Tail fork The body color is bluish gray with yellow, and there are several gray longitudinal lines along the scales. A small part of dorsal fin, gluteal fin and caudal fin are gray-black, while most of ventral fin, gluteal fin and caudal fin are yellow. The fish is widely distributed in Japan, North Korea, the Philippines, Indonesia, the Red Sea and the coastal areas of China, Taiwan Province, Fujian, Guangdong and Guangxi. It is also distributed in brackish waters of estuaries. Basic introduction Chinese scientific name: yellow fin snapper Latin scientific name: Acanthopagrus latus? (Houttuyn, 1782) Another name: Sparus latus? (Houttuyn, 1782) Boundaries: Animal kingdom: Chordata subfamily of Chordata: Vertebrate subfamily: Actinopterigii subfamily: Actinopterigii subfamily: Perciformes subfamily: Sparidae: Acanthopagrus. Species: Apostichopus flavipectus A. latus Distribution: Japan, Korea, Philippines, Indonesia, Red Sea, China, Taiwan Province and Fujian. Brief introduction, other information, morphological characteristics, habits, economic and nutritional value, biological characteristics, breeding technology, seedling production, pond culture, disease control, anchor head flea disease, exophthalmos, Pasteurella, body surface canker disease, gourmet dishes, brief introduction of yellow fin snapper, also known as yellow wall, yellow foot stand, red wing and so on. It belongs to Perciformes Sparidae, widely distributed in the Red Sea, Arabian Sea, Indian, Indonesian, Japanese, Korean, Philippine and China offshore. It is one of the important economic fish along the coast of South China. Yellow fin snapper is a kind of edible fish with rich nutrition, beautiful meat quality and high economic value, and occupies a certain position in seawater and brackish water aquaculture. Teleost, Perciformes, Sparidae. It is about 15 ~ 25 cm long. The body is oval and the side is flat. The head is big and the front end is sharp. The mouth is in the front position, and the mouth fissure is horizontal. There are conical teeth in the front of the upper and lower jaws and molars on both sides. The lateral line has 44 ~ 46 scales, and there are usually 5 scales on the lateral line. The body has several black longitudinal bands, and the lower leaves of ventral fin and gluteal fin are yellow. It is a warm-temperate shallow sea bottom fish. I like to live in the rocky sea area. Generally, long-distance migration is not allowed. Omnivorous, eating shellfish, prawns, crabs, algae and organic debris. The reproductive period is from December to January, and the young fish are hermaphroditic. Distributed in China, Korean Peninsula, Japan and the northern coast of Indian Ocean. China is made in the South China Sea and Taiwan Province Strait. Yellow fin snapper has high economic value, good meat quality and rich fat, so it can be used as a breeding object in Hong Kong, and it can be bred in coastal harbors in spring. Sparus flavipectus is a warm-water bottom fish in shallow sea. The suitable temperature range of young fish is narrower than that of adult fish, the survival temperature is 9.5 ~ 35℃, and the optimum water temperature for growth is 24 ~ 28℃. Adult fish can resist the low temperature of 2℃ and the high temperature of 35℃, and the optimum water temperature for growth is 26 ~ 3℃. It has a wide range of salt tolerance and can survive in seawater with salinity between .5 ‰ and 4.3 ‰. It can be directly moved into fresh water from seawater and grows best in brackish water. Larvae mainly feed on animals; Adult fish mainly feed on plants, mainly benthic diatoms and small crustaceans. The requirements for bait are not strict. Larvae often eat each other because of hunger. The feeding intensity is the highest when the water temperature is above 24℃. The first-instar fish is 16.9 cm long and weighs 15 grams. The 2 nd instar fish is 21.8 cm long and weighs 325 grams. The 3 rd instar fish is 26.2 cm long and weighs about 55 grams. Yellow-finned snapper has obvious reproductive migration activity, which moves from the coastal brackish water area to the deep-sea area with high salinity about two months before spawning, and then returns to the coastal area after spawning. The gonads of the first-year-old fish begin to develop and mature at the second-year-old fish. The suitable temperature for spawning in the south of China is 17 ~ 24℃, spawning from late October to February of the following year, and fry can be seen from January to February. Yellow-finned snapper is a kind of marine warm-water inshore fish, which is widely distributed in the East and South China Seas of China, and it is also a good mariculture species. Other information Yellow-finned snapper is an omnivorous fish which mainly feeds on animals. Because of its small mouth crack, it can only eat small individuals of fish and shrimp. In general, it is a regular practice to chop small fish with a meat grinder and feed them. The optimum water temperature for the growth of this fish is 28 ~ 3℃. Under this temperature condition, its food intake is the largest and its growth rate is the fastest. When the water temperature drops below 1℃ or rises above 32℃, its appetite decreases, and even it stops eating and lies on the bottom of the water. The suitable salinity range is preferably .5% ~ 1.2%. It can be cultured in ponds or cages. Because the yellow fin snapper is petite, it is easy to cause death with a little damage on its body surface. Therefore, special care should be taken when operating the fish body to prevent the fish from being injured on the body surface or from dying of bad breath caused by muddy fish gills. Morphological characteristics: the body length is 13~3.6 cm. Tall, flat-sided, oblong, long and narrow back, blunt and round abdomen. Blunt kiss. The body is thin and comb-like; There are scales on the cheek and the top of the head, and the cheek scales are 5 rows. The lateral line is complete, arc-shaped and parallel to the back edge. The spine of dorsal fin is connected with the fin strip. The pectoral fin is long. Abdominal fin chest position. The body color is bluish gray and yellowish, and there are several gray longitudinal lines along the scales. A small part of dorsal fin, gluteal fin and caudal fin are gray-black, and most of ventral fin and caudal fin are yellow. Dorsal fin Ⅶ-11; Gluteal fin ⅲ-8; Pectoral fin 14-15; Abdominal fin ⅰ-5; Tail fin 17. Lateral line scales 44-46. Gill harrow 6+8-9. The specimen was 115-22 mm long. Body length is 2.3-2.5 times of body height and 3.-3.5 times of head length. The head length is 2.6-3.3 times the length of the kiss and 3.8-3.9 times the diameter of the eye. The body is oval and the side is flat. The head is large, the front end is pointed, and the left and right frontal bones are separated. The mouth is large and almost horizontal. There are 6 conical canine teeth at the front ends of the upper and lower jaws. The body is comb-shaped, with complete lateral lines, parallel to the back edge and arc-shaped. The dorsal fin is continuous, and there is no carving in the middle. The pectoral fin is in the lower lateral position, and the rear end extends above the starting point of the gluteal fin. The ventral fin is small, chest position. The caudal fin is bifurcated, and the upper and lower leaves are pointed at the ends. The body is bluish gray and yellowish. There are several black longitudinal bands and four diagonal transverse bands on the side of the body. The lower leaves of ventral fin, gluteal fin and caudal fin are yellow. It is a shallow bottom fish, omnivorous and gluttonous. From December to January, the young fish are hermaphroditic. It is an important economic fish. Distributed in South China Sea and Taiwan Province of China; The northern coast of the Indian Ocean, the Red Sea, Indonesia in the east and North Korea and Japan in the north. Habitually living in the waters of 1 ~ 5m, it often moves near the shed of the clam, mangrove forest or wave-absorbing block in the dike area in the estuary area, and belongs to euryhaline fish. Omnivorous, mainly algae and small benthos. It breeds in winter and gathers at the estuary of the river to lay eggs. In spring, young fish begin to appear in the estuary and can swim back to the fresh water area. Origin: mainly distributed in the coastal areas and estuaries of the South China Sea, occasionally entering fresh water. Artificial farming has been carried out in Guangdong. Yellow fin snapper with economic and nutritional value is a superior fish, and its meat is tender, suitable for fresh food and salt. Yellow-finned snapper is a medium-sized edible fish with high economic value. It is a best-selling aquatic product in the mainland, Hong Kong and Taiwan markets, and has become an important mariculture object in the coastal areas of China. China was successfully artificially propagated in 198, and it can be mass-produced, which will further promote the breeding scale of yellow fin snapper. In the muscle of Sparus flavipectus, the mass fraction of each component in fish muscle is crude protein 21.1%, crude fat 1.31%, crude ash 1.5% and water 74.4%. The total amount of hydrolyzed amino acids in dry matter is 76.38%, of which the essential amino acids are 32.46%, accounting for 42.5% of the total amount of amino acids; Taste amino acid w32.51%, accounting for 42.56% of the total amino acid. Methionine is the first limiting amino acid, and the content of lysine (per gram of nitrogen) is the highest, reaching 494 mg/g. Taurine content is 34mg/kg. Yellow fin snapper is a delicious food with high protein and low fat, so attention should be paid to the protection of germplasm resources. Biological characteristics 1. Ecological Habits Yellow-fin Sparus is a shallow-sea warm-water bottom fish, which likes to live in rocky sea area. The living temperature range of young fish is narrower than that of adult fish, with the optimum temperature for survival of 9.5-29.5℃ and the optimum temperature for growth of 17-27℃. Adult fish can resist the low temperature of 8℃ and the high temperature of 35℃. Yellow fin snapper can adapt to drastic salinity, and can be directly put into fresh water from seawater. After a week of adaptation, it can return to seawater and still live normally, and it grows best in salty fresh water. Generally don't do long-distance migration. Second, the edible yellow fin snapper is an omnivorous fish, and benthic algae, benthic crustaceans, zooplankton and organic debris in the water are all palatable bait. The larval stage is dominated by animal bait, and the adult fish is dominated by plant bait. In early summer, when the water temperature rises to 17℃, the food intake begins to increase, and at 2℃, the food intake is the most frequent. Generally, the feeding activity is the strongest before dusk, and the feeding is rarely or suspended in the middle of the night. Third, the growth rate of growing yellow fin snapper in natural waters is: the body length of the first-instar fish is 17. cm and the weight is 15 g; 2 nd instar fish 22. cm, 33 g; The third-instar fish is 26. cm, 56 g, and the largest individual can reach 35. cm in length and weigh 335 g. Iv. Reproductive Habits Yellow-fin Sparus is a hermaphrodite fish, in which the male gonads mature at the age of 1-2, and turn into females at the age of 2-3. The annual spawning period is early October, which belongs to a batch spawning type. The spawning water temperature is 16-23℃ and the salinity is 25 ‰ ~ 33 ‰. Breeding technology seedlings to produce the seedlings needed for yellow fin snapper breeding, most of them rely on fishing natural fry in the sea area. First, the fishing of the fry should master several technical links: 1. The fishing season of the yellow-finned snapper fry is from the end of November to the end of February of the following year. The first time to see the fry was in mid-November, and the flourishing period was from December to January. After late February, the fry grew up and dispersed, and only a few large fry could be caught. 2, fry specifications and population changes Every year before the "beginning of winter", the yellow fin snapper began to lay eggs, and after the seedlings hatched, they swam to the estuary and the inner bay to feed. In mid-November, a small number of fry with a body length of .5 cm began to appear, and the population of seedlings ashore became larger and larger, reaching the maximum when the body length was about 2 cm. After late February, the fry grew to more than 3 cm and swam to deeper waters. 3. Fishing tools and methods There are three kinds of fishing nets: small towing net, linen purse seine and taping net. The fishing sites of the first two kinds of nets are selected in the shoal where salt and fresh water meet in the offshore estuary and the inner bay, and the sea area with sediment gravel and salinity of 14‰-15‰. In the middle and late stage, you can use brake foil to hunt around the sea. The fishing time is chosen in the advection after the ebb tide, because the seedlings can't quit with the water at this time, and it is easy to catch when they stay in the shallows. When fishing, two people trawl on both sides, and two people drive the seedlings with shell ropes in front, so that the seedlings can slowly swim into the net, and then slowly close the net. When closing the net, attention should be paid to prevent the fry from being injured by friction attached to the net, and to prevent the water from being mixed up, which will lead to the death of the seedlings due to hypoxia and suffocation. Be careful when fishing for fry, and slowly put them into a bucket or cage prepared in advance. Loom fishing should be carried out at high tide. Transportation of fry seedlings 1. Treatment of fry before transportation The fry caught from the sea area should be screened to remove the thin and injured fry, because the injured fry is easy to be infected with bacteria, causing skin inflammation and redness, or water mold, which will spread quickly after illness, causing a large number of deaths. Before shipment, the fry should be hung for 2-3 days to exercise and excrete feces, so as to reduce the pollution of water quality during transportation. 2. Grasp the transportation water. The water used to ship fry should be close to the salinity of the water in the hanging pond, and the salinity should be kept relatively stable when adding water during transportation. 3. Shipping density The oxygen consumption of seawater fry is higher than that of freshwater fry, so the shipping density is less. Generally, a large wooden barrel with a volume of 35kg can hold 5,-6, seedlings with a body length of 1.5cm or 3,-4, seedlings with a body length of 2.5cm.. 4. Oxygen-increasing is an important link in transportation, and the method of combining manual water-striking with oxygen-increasing supplement by air compressor can be adopted. With this method, after 12-16 hours of transportation, the survival rate can reach about 9%. Release seedlings 5. Treatment after transportation to the destination After the fry arrive, the water temperature and salinity should be adjusted well before going into the pool, and it should not be too different from the transportation water. After the fry are unloaded, they should be slightly cleaned, hung in the pond, let the fry rest for 1-2 hours, then clean up the dead fish and dirt, and then count them and move them to the stocking pond. Pond culture 1. Construction of farms The farms should be located near the coast, with abundant water resources, no pollution, convenient transportation, typhoon prevention and tide prevention, and make full use of the fluctuation of natural tides to irrigate and drain water. The farms should have a good irrigation and drainage system and separate irrigation and drainage. Farms without tidal irrigation capacity should be equipped with water pumps or waterwheels for irrigation and oxygenation. Intensive culture ponds generally have an area of 1-15mu, middle culture ponds have an area of 3-5mu, the length-width ratio is 1: .6, the water depth is 1.8-2.5m, the pond foundation is solid and watertight, the water injection and drainage gate of the pond is .8-1m wide, and the maximum daily water exchange capacity is 3%. Before stocking, the pond needs to be sun-dried, cleaned and disinfected to kill wild fish and shrimp. After the gate is installed, water is fed and fertilized to cultivate baits. 2. Culture methods Pond culture of Sparus flavipectus can be divided into three ways: single-species pure culture, multi-species mixed culture and single-species collocation culture. ① Single rearing. Stocking 7-15 fish per mu, putting fry in January-March every year, with the specification of 2-5cm, the breeding period of 1 year to 1.5 years, catching more than 2g, feeding chilled fish and artificial feed, and the yield per mu is generally 15-3kg. ② Multi-species polyculture. Polyculture can make rational use of aquaculture water bodies and maximize the productivity of water bodies. The commonly used polyculture methods are: a. polyculture of yellow fin snapper, mullet and blue fish. The stocking amount of three kinds of fish in mixed culture is 5-7 (5-7 cm), 2-3 (7-8 cm) and 2-3 (5-7 cm) per mu, respectively. After one year of culture, the yield of yellow fin snapper can reach 1-15 kg. B yellow fin snapper, money fish and blue fish are mixed. The stocking amount of three kinds of fish in mixed culture is 7-9 (5-7 cm), 2-3 (5 -1 cm) and 2-3 (5-7 cm) per mu, respectively. After one year of culture, the yield of yellow fin snapper mu can reach 15-2 kg. ③ Single-culture-based collocation culture. This is a kind of culture method to make use of the surplus bait inevitably produced in the intensive culture of a single species, and to adjust the water quality caused by excreta to be too fat and plankton to multiply in large quantities. Generally, one species is mainly raised, supplemented by one species: A-perch and Sparus. The stocking amount per mu is 7-8 (1 -12 cm) and 2-25 (5-8 cm) respectively; B bass,