I. Biological characteristics of several species of carp Peng’s biological characteristics
(A), external morphology characteristics
1. The color of Pengze's back is dark grayish black, and its abdomen is grayish white. The fins are blueish black with deeper pigmentation. The color of odd fins is deeper than that of even fins.
2. Body type is spindle type. The head is short, the kiss is blunt, the mouth is curved, and the lips are thick. Medium to large eyes, no need, slightly upward mandible oblique, from the bottom of the mandibular to the base of the pectoral fins showed a gentle arc, tail height higher than the length of the head behind the eyes.
The outer edge of the dorsal fin is straight, and the distance from the starting point to the snout end is equal to or slightly closer to the base of the caudal fin. The pectoral fins of males are longer and longer, and the ends of the pectoral fins can reach the base of pelvic fins. The pectoral fins of females are more rounded and do not reach the basal pelvic fin base. The position of the pelvic fin originate slightly before or at the beginning of the dorsal fin. The ventral fin does not reach the anus at the end of the dorsal fin, and the caudal fin is moderately long and bifurcated.
3. Reproductive body size/body height 2.70; Body length/head length 3.85; Body length/tail height 6.34; Tail height/tail length 1.2; Head length/kiss length 3.78; head length/eye diameter was 4.70; gut length/body length was 3.48; and empty shell rate was 81.1% (without sputum, scales).
(B), living habits Peng Zeyi is a wide-temperature, omnivorous lake settlement fish, camp benthic life. Hi inhabiting and feeding in shallow water areas where fertility is more abundant and aquatic wetter.
(1) Peng Zeyi has a wide range of water temperature adaptations and can feed and grow normally throughout the year. In the severe cold of the lunar month, more than 80% of individuals have I to II degree of intestine in the intestine. Even in ice-cold bodies, Peng Zeyi can live well. When the water temperature reaches 38°C, it does not affect it. survive. Its optimal growth temperature is 25-30 °C. Within this temperature range resistance, Peng Zeyi ingested food with the fastest growth rate. The growth period is from April to November in the Yangtze River basin, of which the fastest growth rate is from August to September.
(2) Peng Zeyu has a strong ability to adapt to adverse environments. In addition to its wide adaptation to water temperature, it also has strong endurance to physical and chemical factors such as pH and low dissolved oxygen in water bodies. The breeding and promotion test proved that Peng Zeyu is suitable for aquaculture in various water bodies, and is particularly suitable for growth in waters with fertile bottoms and rich benthic organisms.
(C), food Pengze eating a very wide range of food, with the amount of food organisms in the water there is a change in the number of omnivorous fish. In the natural waters, Peng Zeqi can use zooplankton and phytoplankton as food, but also feed on benthic flora and fauna and organic debris. The type of food varies according to its individual size, season, environmental conditions, and the dominant population in the water.
After 2 to 3 days after filming, Pengze’s fish fry rely on absorbing its own yolk as a nutrient. The larvae began to actively ingest zooplankton (such as small rotifers, small larval larvae, copepods, etc.), phytoplankton, and organic debris; juveniles and adult fish that were 4-6 cm in length, except Still taking organic detritus as the main feeding target, it also feeds on aquatic insect larvae, epiphytic algae, and young leaves and shoots of aquatic vascular plants.
In artificially cultivated ponds, Pengzeyu summer fish can be fed with soybean milk, wheat bran, feed powder, cakes and artificial feed. At the same time also eat the natural food in water.
Peng Zelu is a fish that feeds all year round, and its ingestion intensity follows the law of feeding of warm-water fish. In the spring, summer and autumn seasons, the intensity of feeding was greater (in the autumn, it was the maximum), and in winter, as the water temperature decreased, its feeding intensity gradually weakened, but the critical water temperature that Peng was eating was slightly lower than that of other carp species. The water temperature was 11 Below <RTI ID=0.0>C,</RTI> individuals with higher ingestion intensity (grades III to IV) can still be seen.
(IV) Growth Peng Zeyu is a large carp, known for its fast growth and large individuals. Common individuals weigh more than 250 grams, and the largest known Pengze louses are 4 kg and 6.5 kg, respectively.
In natural waters, Peng’s body growth and weight gain were the fastest in the year of birth, reaching 16.6 cm and 127.9 g respectively. The weight gain of the 2nd instar fish is still faster, which is 50.61% higher than that in the morning. The 4th instar fish still maintains a growth rate of 29.85% over the previous year.
After breeding, Pengze was cultured in ponds and had a faster growth rate, which was 56% faster than before breeding. In artificially cultivated water bodies, the growth of Pengzeyao is largely influenced by factors such as the density of the fish stocks, the stocking species, and the abundance of bait. Under normal circumstances, the pengyu fish fry which was bred in that year, after growing for about 6 months, has an average body length of more than 19 cm and a body weight of about 200 g.
(5) Breeding habits Peng Zeyi can lay eggs in rivers and lakes, as well as spawn in ponds. He can either reproduce naturally or produce artificially. 1 Peng Zeyi of the winter (12 months) can reach sexual maturity. Female sexually mature individuals weigh more than 170 grams and have a maturity factor of 14.8%, ie, 14.8 grams of ovaries per 100 grams of fish body weight. The relative amount of eggs was 151 eggs/g body weight. When entering the wintering period, the ovary develops to the beginning of III-VI. Male sexual mature individuals have a smaller body weight than female individuals, and their sexual maturities range from 4.3% to 4.67%. When they enter the overwintering period, the testes can develop to N stage, and sexual maturity is earlier than that of females. ~ 2 months. In the natural population, the female to male ratio is 10 to 12:1. Peng Zeqi is a normal diploid (2n=100) sexual reproduction group, producing sticky yellow eggs, which is a type of multiple egg production. Eggs are fertilized by single sperm. The resulting eggs are sticky when they come into contact with water and they swell with water. They stick to the aquatic plants or suspended in water on the basis of the stickiness of the egg membrane. The diameter of the newly produced eggs is about 1 mm, and the diameter of the eggs after water swelling Up to 1.5 mm. The fertilized eggs are colorless and transparent, and the unfertilized eggs are milky white and will soon dissolve. When the water temperature is 18 to 20°C, it takes about 53 hours and 15 minutes from fertilization to hatching. When the incubation temperature is 16 to 17°C, the incubation time is about 143 hours. The newly hatched larvae exit the membrane, and the larvae emerged completely. About 3 mm long. Often attached to his place, he swings intermittently and begins feeding. The time from hatching to horizontal swimming is approximately 50 hours. From March to July each year, Pengze's breeding period and April's breeding season. In the southern region, generally after mid-March, when the temperature of the water rises to around 17°C, Peng Zeqi begins to lay eggs. When the water temperature rises to 20 to 24°C, the breeding activity is most prosperous. Rainfall, microfluidic, and hot climate have a role in inducing spawning during the breeding period. Under natural conditions, Peng Zeyi likes flowing water, and especially prefers to breed eggs in micro-flowing water with a certain degree of turbidity and in dense shallow water areas.
Osaka's biological characteristics
First, the morphological characteristics
(a) The body color of Osaka osmanthus is silver-white and each fin is silver gray and black.
(B) Although the body is long, but the body is laterally flat and high, the front back hump slightly humpback type. Abdomen without edges. The head is small and the kiss is blunt. Small mouth, end position. No need to quarrel. Pupils are smaller and their eye diameter is 2.25 times that of the pupil. Eye wide spacing. The tail is relatively slender and the caudal peduncle is longer than the caudal peduncle. The starting point of the dorsal fin is closer to the snout than to the tail base. The outer edge of the dorsal fin is slightly concave. The pelvic fin origin is opposite to the starting point of the dorsal fin and does not reach the anal fin. The starting point of the anal fin is closer to the base of the pelvic fin than to the base of the pelvic fin, and the third hard thorn of the anal fin is thick. The caudal fin bifurcates and the ends of the upper and lower leaves are rounded. The anus is located before the starting point of the anal fins.
First, living habits Osaka Sakamoto live in the water, in the upper, hi cluster. The water temperature has a wide range of adaptability and can survive well in the water bodies in China. It does not need wintering and avoiding the cold. It has strong tolerance for low dissolved oxygen in water bodies. Osaka's oxygen consumption rate is lower than that of northeastern silver storks and wild pheasants, but higher than that of heterotrophic silver gilts. From the time when the test showed a serious floating head to the total duration of death due to hypoxia and suffocation of all test fish, the Osaka pigs could endure for 11 hours (asphyxiation point of 0.2 mg/g) and the wild horse had only 7 hours of endurance ( The asphyxiation point was 0.23 mg/l. It can be seen that the Osaka wolfberry is more tolerant to hypoxia. Osaka 鲫 can tolerate the ability of low dissolved oxygen, which is beneficial for pond feeding management and transportation.
Second, the food of Osaka Stork can live in a variety of bodies of water, the ability to adapt to food, can change the type of food with the number of food organisms in the habitat, including feeding artificial feed. When Osaka fishes in the juvenile stage, it mainly eats zooplankton (including small cladocera, colisters, and rotifers). When Osaka's carcass reached 8 centimeters in length, it began to feed mainly on phytoplankton but also ate organic detritus and artificially fed commercial feed. It also consumed a small amount of zooplankton. However, as Osaka's carcass length reached 31 cm, it almost ingested phytoplankton in the water, and the intestine was filled with dark green algae. In Japan, Mizuhiko Mizuno monocultured or codfishes with squid in eutrophic ponds and eutrophic ponds. The result was an interesting phenomenon: in oligotrophic ponds, lack of phytoplankton, feeding Is a large number of cladocera and benthic diatoms; when Osaka wolfberry monoculture in an eutrophic pond, due to the blue and green algae in the water as the dominant population, it will be the main food (90% of the food in the intestine) (Left and right); Although Osaka Stork lives in another eutrophic pond, it is mixed with squid. At this time, Osaka oysters are the main food rotifers and benthic diatoms, while squid are all ingested phytoplankton. It can be seen that the food habits of Osaka oysters will change with changes in environmental conditions in order to survive. In addition, according to a report from the Sun Yat-sen University in Guangzhou, at a water temperature of 24 to 27.5°C, Osaka Sakai (testing a body weight of 9 to 13 grams, with a total of 86 tails) was able to ingest silky algae, the Spirogyra. The trace test and autoradiography of the fish body confirmed the ingestion and digestion and utilization of Spirogyra in the Osaka salmon species. The ingestion rate (percentage of daily fish consumption in the fish body) for the Spirogyra was 1.85% to 4.00%. The actual digestion and absorption rate of Spirogyra is 48.49%. Spirogyra is widely distributed in natural water bodies. It not only has strong fertility and fast growth rate, but also absorbs artificially applied fertilizer in ponds to make the water thin, which is very unfavorable to the growth of grasshoppers and carps feeding on plankton. Sometimes it is also possible to encroach on the fry and cause death, causing a harmful factor in fish farming. To some extent, Osaka Stork can ingest digestive water, which not only harms the benefits but also contributes to the growth of other fish. At the same time, it is also an excellent example of "biological control" without pollution.
In summary, it can be seen that the food habits of Osaka Stork are very broad and omnivorous. Therefore, according to its food habits, it is necessary to lead the breeding of its own. For example, during the fry incubation period in Osaka, a large number of zooplankton must be cultivated for their food intake. When the osaka osaka gradually grows up to the rearing stage, the combination of fertilization and feed should be paid attention to in the water body to ensure that both the rich natural feed and the artificial feed containing various nutrients are included in the water body. In order to meet the needs of its growth in a good ecological environment, this is a successful experience in raising Osaka Osaka.
Second, the salmon fish breeding
(1) Peng Zeyi's breeding Peng Zeyi's broodstock requires a mature individual with typical characteristics of robustness, no injury, and no injuries. When the broodstock was selected from the fish of the year that was reared in the fingerling pond and the wintering of the fingerlings and the pond after November of that year, Pengzeyu of more than 200 grams per tail was collected and placed in the clear pond. In winter, the ponds with deeper water levels are overwintering and serve as spawning broodstock for the second year. During the wintering period (December to February of the following year), when the weather is fine, the concentrate should be fed in an amount of about 2.0% of the fish's body weight. After the spring, the male and female penguin should be fed in a timely manner to prepare for prenatal training and strengthen management. The overwintering of broodstock and the quality of prenatal culture directly affect the amount of broodstock, maturation coefficient, spawning rate and emergence rate.
In the breeding season, the ovaries of female broodstock are obviously contoured, the abdomen is flat and soft, the anus is red and swollen and congested, and the abdomen is often pressed to squeeze out the granules. The fish has more smooth mucus. Male broodstocks have "stars" appearing on the head and chest. The skin on the surface is rough and the abdomen is not contoured. Milky white semen flows out of the lower abdomen. In the non-breeding season, the male has a relatively long pectoral fin, and the tip of the pectoral fin can reach the starting point of the pelvic fin. Female pectoral fins are fan-shaped and shorter, and do not reach the starting point of the pelvic fin. The pond with an area of ​​0.04 to 0.07 hectares of spawning ponds served as a good spawning pool for Pengzeya broodstock. 7 to 10 days before oxytocin production, clear ponds, disinfection, killing of wild fish such as squid, and cleaning of water and other debris are performed. Then, about 70 centimeters of water is used for spare. When the water is injected, it should be filtered with a dense sieve to prevent the wild fish from entering the spawning pool. The water lettuce, palm, or willow roots were sterilized with (10 to 20) X10-6 potassium permanganate or 1/5000 malachite green, and a fish nest was placed in the pond. Male to female ratio (1 ~ 3): 1 release broodstock, water temperature under natural conditions, 17 °C to death, broodstock estrus and breeding their own eggs, will be attached to the fertilized eggs from the nest of another hatch hatching fry. This method is simple and easy for small-scale production. Its main disadvantage is that the spawning cycle is long and the emergence time is inconsistent. It is not convenient for the next stage of feeding and management.
In order to achieve the same specifications of batch fry, artificial ovulation can be performed. Male and female broodstock, according to the proportion of (2 - 3):1, when the water temperature reaches above 17 °C, a single injection of HCG (chorionic hormone) 800-1200 units per kilogram of female fish, or LRH-A (luteinizing hormone Releasing hormone analogs) 20 to 30 micrograms, or according to instructions for use of the drug. The male injection dose is halved. The injection site is usually at the base of the pectoral fin without scales. The injection time is preferably from 3 to 5 pm. The effect time is 9 to 16 hours (water temperature 18°C ​​to 20°C), and the total spawning time lasts 6 to 20 hours. Estrus chase is often below the surface of the water, and the sound of water waves and blows is small. The brooded brooding brood of the pengwa broods will be eaten by the brooded broodstock. After the broodstock spawns, the broods filled with fertilized eggs should be immediately transferred to the hatchery for hatching.
(b) The Osaka Stork has a reproductive weight of 250 grams or more, a strong physique, no injuries, and two-year-old Osaka oysters can be used as breeding broodstock. The broodstock should be cultivated before spawning. In addition to feeding good feed, it is also necessary to pay attention to the management of good water quality, so that the phytoplankton in ponds can be maintained at a certain level to ensure the nutrients required for gonad development. During the breeding season, sexually mature males and females can pair themselves in natural waters or ponds and spawn. Therefore, clear ponds and disinfection work must be conducted before the breeding ponds are hatched. Like other salmon breeding, the fish nests should be prepared and the broodstock should be put in. Male and female broodstock, according to the ratio of (2 ~ 3): 1 matching group, and then given microfluidic stimulation, usually the broodstock can naturally spawn, if the pro-fish into the pool, the injection hormone aphrodisiac, spawning will be more smooth and synchronized. The artificial propagation and hatching techniques of Osaka Stork are similar to those of Peng Zezheng. Refer to the operation.
(3) The seedling culture techniques of carp seedlings for breeding several carp species are similar and are presented here. The newly hatched larvae cannot swim because they are very tender and small, and they are in the "nest stage" stage. Don't rush to remove the fish nests. After 2 to 3 days, the yolk of the larvae disappears, and the larvae are inflated. When the fry can swim in peace, the fish nest can be removed and the cooked egg yolk or soybean milk can be fed in time. Generally, soybean milk is fed 2 or 3 times a day. Every 0.07 hectare of water uses 3 to 4 kilograms of soybeans every day. After 10 days, some concentrated feeds and top-up manure and other organic fertilizers are added. In order to promote the growth of fry, during fry cultivation, it is necessary to inject new water 2 to 3 times, so that the water depth is maintained at 1.0 meters, and each time water is injected 5 to 10 cm. After 15 days of cultivation, the fry can be up to 2.0 to 2.6 cm in size. At this time, soymilk can be stopped. It can grow to 3.0 to 3.5 cm in 20 to 25 days and enter the next stage of cultivation. In fry cultivation, as the fish grow up, the density of the fish in the pond is often too high, which is not conducive to the growth and management of the fry, so it needs to be cultivated in a timely manner. Usually 7 to 10 days after the larvae have been raised, the fry is carefully and slowly raised in a cage (fish) cage or box, and moved to a pre-prepared fry pool after a few hours. The cultivation method is the same as above. Each 0.07 hectare of water surface stocking density of 150,000 to 200,000. When the eel fry reaches 3.0-3.5 cm, the size of the fry of the four large populations in most parts of the south is about 1.5-1.8 cm. At this time, 3.0-3.5 cm of fry can be pressed. A density of 2000-3000 tails/0.07 hectares was housed in a fry breeding pool for the four-masts. After 15 to 20 days of feeding, the size of the fry of the four home fishes reaches 2.5 to 3.5 cm, which can be transferred to the pond for breeding or sale. The size of the carp seedlings is up to 5.0 cm or more. This type of fry has Facilitating the development of Peng Zeyi's fish into adult fish.
Third, carp adult fish breeding
(I) Pond farming Eel adult carp is cultured in ponds. It mainly adopts four farming methods: polyculture in adult fish ponds, stock raising in fish ponds, broodstock pool raising and pond main breeding.
1. In the adult fish pond, polyculture of squid, and green, grass, alfalfa, alfalfa, alfalfa, pupa, alfalfa and other varieties of polyculture. Large-scale species should be stocked. The time for stocking should not be late, that is, winter stocking is better than spring stocking. Stocking density is 150 to 250 tails per 0.07 hectares of water. The stocking specifications and quantity of other fish are determined as needed. The requirements for aquaculture ponds are not high, generally 0.1 to 2 hectares, and ponds with a water exploration of 1.5 meters or more. At the bottom of the pool, 10-15 cm thick silt is the best. The cleaning, disinfection, and basal fertilization of ponds were performed according to conventional methods, and the survival rate was about 80%. After 200 days of feeding, the majority of individuals weighing 200 grams or more are considered to be the vast majority. The output of each 0.07 hectare of water is more than 20 kilograms.
2. The main pond raising requirements of the carp are 0.1 to 0.2 hectares, with a depth of 1.5 meters or more, and 10 to 15 centimeters of mud at the bottom of the pond. The ponds with domestic sewage behind the houses have better effects on the main carp. . One week before the stocking of fish, it was disinfected with quick-lime clear ponds, and water was injected 2 to 3 days after disinfection. During the water injection, the grid was used to filter at the inlet to prevent wild fish from entering the pool. 5.0 to 6.5 cm per 0.07 hectare of water main fish wintering species of 1500 or 2,000 large-scale fry hatched in the current year, with about 40% (600 to 800) of grass, cockroaches and cicadas wintering species . Restocking time should be sooner rather than later. The daily feeding of concentrate feed is the main method, combined with the water quality of fertilization culture. The annual feed amount of concentrate feed is equivalent to about 2.5 times of Peng Zeyu's estimated production. With fixed-point feeding, the daily feeding amount depends on the growth of the fish body, the weather, the water temperature, and the ingestion intensity of the fish, and fertilizes or refills the new water according to the water quality. Under the general management level, 200 kg of squid with an average weight of 150 g/swallow and about 200 kg of grass, squid, and squid were obtained in the same year. As the proportion of high-quality fish is higher, its net profit is also higher than other farming models.
3. The fry pool sets up squid. Can be set in the green, grass, alfalfa, clams, cockroaches, clams and other fish fry pool, rather than suitable for nesting in trout, tilapia fish species pool. The area of ​​nesting ponds requires 0.1 to 0.2 hectares, and the depth of water is 1.0 to 1.5 meters. The pond cleaning, disinfection, and basal fertilization are the same as the conventional method. The carp is nested in other fry pools and can only stock the fish species hatched in that year. It is advisable to have a stocking time sooner than usual. Normally, when the fishery species hatched in the main breeding year is transferred into the wintering species, the fish species hatched in the year should be released immediately; the stocking size should not be small, and the stocking density should be 150 to 220 tails per 0.07 hectare of water. The number of stocks, specifications, and combinations of fish species that were hatched in other years were determined based on production needs and specifications of the outlet ponds. Because it is a bottom fish, the eel seedlings generally do not affect the living space of the fish species and can fully utilize the water space. Therefore, the fish species hatched in the year were reared in the fry pool, which basically did not affect the stocking densities of the main fish species and the specifications of the outlet ponds; Therefore, there is basically no need to increase funding and feed input. Under normal feeding and management conditions, carp seedlings are nursed in fry pools and raised for 150 to 180 days. The water size at the end of the year can reach more than 200 grams. Each 0.07 hectare of water surface can increase the amount of adult fish from 25 to 40 kilograms.
4. The broodstock breeding pond sets up squid. In southern China, the artificial breeding of domestic fish is generally completed from mid-May to the end of May. The gonads of the postpartum broodstock are in the recovery period. In order to restore the body strength of the broodstock as soon as possible and promote the development of gonadal, the ponds are mostly intensively managed. In addition to broodstock breeding and other fish, this fish pond can accommodate up to 200 tails of 5 to 6 centimeters per 0.07 hectare of water. The broodstock is reared in a broodstock breeding pond and the stocking time is usually carried out at the same time as the broodstock. The culturing (breeding) method is performed according to the conventional method of raising the broodstock. Bred broodstock should follow its law of gonad development. The broodstock nursery ponds generally cannot be caught in dry ponds at the end of the year, and can only be completely arrested when the broodstock is used for prenatal strengthening. After feeding for 250-300 days, 25-45 kg of carp can be obtained per 0.07 hectare of water surface, and the average body weight is more than 200 grams.
(B), rice field farming carp fertile soil, irrigation is convenient, good water retention and fertilizer performance of rice fields can be farmed carp, generally double-season rice farming, single-season rice due to short time, it is difficult to reach the adult fish breeding specifications. Before the fish is released, depending on the size of the paddy field, the source of the water, the water inlet and outlet, etc., the field hoe, fish slip (fish pit), and fish ditch are excavated in the field. Tianshun requires solid and watertight. The area where the fish slides varies from place to place. Each 0.07 hectare of water is between 3 and 5 m2, with 20-30 meters more than the average. The average area of ​​the fish is about 5%, and the water depth is 0. .8 meters can be, depending on the shape and size of the fish ditch, depending on the shape and size of the field, there are "a" shape, "10" shape, "shi" shape, "å…" shape and "kou" shape and other forms. Rice-field cultured squid can be cultivated or mixed, and the stocking size of 5.0 to 6.5 cm is better. One week after the transplanting of the early rice, the fish species will be released and 250 to 500 fish fry per 0.07 hectare. Without feeding, more than 20 kilograms of carp can be harvested after the fall, with an average tail weight of about 100 grams. If some concentrate is used, 0.07 hectares of carp can produce more than 35 kilograms. Daily management is the same as that of other fish. To encourage the use of organic fertilizers to increase the richness of organic matter in paddy fields so as to facilitate the growth of carp. At the same time, do a good job of anti-escape equipment to prevent the top water to escape.
(3) Small-sized reservoirs and lakes Breeding squid Small lakes and reservoirs rich in natural food and water quality are suitable for stocking squid, and larvae that use feeding or fertilizing or semi-intensive breeding lakes and reservoirs have better effects. Within 1 to 3 years, lakes and reservoirs for dry lakes or dry storage, and stocking squid, can generally achieve very good results in increasing production and income. Due to the relatively large water surface of lakes and reservoirs and the predation of more fish, in order to increase the survival rate of earthworms, large-scale fish species should be stocked as far as possible, and stocking density should be 20-50 per 0.07 hectare. Stocking time can be both winter and spring. The high-yielding lakes and reservoirs that are released every year for fishing can increase the stocking amount of squid, and can be standardized and managed according to pond farming squid technology. In lakes with rich natural foods and fertile water, the growth rate of carp is even higher than the speed at which it grows in ponds. In that year, the weight of a carp was 250 g or more, and the lakes and reservoirs of dry lakes or dry lakes for 2 to 3 years had a body weight of 500 grams or more accounted for a considerable proportion.
(D), cage culture of carp use of reservoirs, lakes and other large water surface for intensive production of cages, do not occupy the land area and the surface of the pond, is a new breeding mode of the attempt. As large reservoirs, lakes, and other large water surface, making the cage inside and outside the water body can be fully exchanged, so the dissolved oxygen is sufficient; the second cage cultured fish activity is small, less energy consumption, which are conducive to the growth of carp. The specifications of cages generally require an area of ​​16 to 28 m2 and a height of 2 to 3 meters. The size of the mesh depends on the specifications of the stocking species, and large meshes are used as far as possible without increasing the size of the fish. Exchange of water inside and outside the large box. It is better to use 3X3 polyethylene mesh wire as cage material. Mesh cages are often installed in floating and fixed ways. The distance between the boxes is 2 to 3 meters and the row spacing is about 20 meters. Determining the location of the cage setup takes into account the following factors:
(1) Choose slow water flow. The area where the water level is stable, sheltered from the sun, and has a flat bottom is preferably a sandy bottom with a water depth of 5 to 6 meters.
(2) The surrounding environment is required to be rich in vegetation, water quality is fertile, and dietary food is abundant.
(3) Industrially polluted waters cannot be used as a cage setting site.
Cage cultured carp generally adopts single-culture mode and can also be used with a certain proportion of plutonium, alfalfa and alfalfa, generally controlled within 3% to 5% of the total output. A 50 to 200-sold eel fry with a size of more than 5 cm per square metre should be stocked, and the fish in the same cage must be fully loaded at one time. Stocking specifications must be neat, otherwise the size of the fish will become more and more disparate. Catfish farming in cages must be baited. It is better to feed artificial compound feed, semi-floating or sinking granular feed. The bait formula can refer to the formulation of the squid cage culture and the protein content can be slightly lower than that of the squid bait. Feeding a small number of times, is the principle of feeding cage fish. Each time the amount of bait was eaten with 90% of the bait before it was leaked out of the cage, the least amount of bait that was finally put into the diet was the criterion for determining the amount of each feeding. Daily feeding 4 to 6 times, no feeding at night. Other aspects of daily management are no different from conventional cage fish farming. After 180 to 200 days of feeding, the average body weight of the fish can reach more than 200 grams, and the output per square meter can reach 8 to 25 kilograms.
(A), external morphology characteristics
1. The color of Pengze's back is dark grayish black, and its abdomen is grayish white. The fins are blueish black with deeper pigmentation. The color of odd fins is deeper than that of even fins.
2. Body type is spindle type. The head is short, the kiss is blunt, the mouth is curved, and the lips are thick. Medium to large eyes, no need, slightly upward mandible oblique, from the bottom of the mandibular to the base of the pectoral fins showed a gentle arc, tail height higher than the length of the head behind the eyes.
The outer edge of the dorsal fin is straight, and the distance from the starting point to the snout end is equal to or slightly closer to the base of the caudal fin. The pectoral fins of males are longer and longer, and the ends of the pectoral fins can reach the base of pelvic fins. The pectoral fins of females are more rounded and do not reach the basal pelvic fin base. The position of the pelvic fin originate slightly before or at the beginning of the dorsal fin. The ventral fin does not reach the anus at the end of the dorsal fin, and the caudal fin is moderately long and bifurcated.
3. Reproductive body size/body height 2.70; Body length/head length 3.85; Body length/tail height 6.34; Tail height/tail length 1.2; Head length/kiss length 3.78; head length/eye diameter was 4.70; gut length/body length was 3.48; and empty shell rate was 81.1% (without sputum, scales).
(B), living habits Peng Zeyi is a wide-temperature, omnivorous lake settlement fish, camp benthic life. Hi inhabiting and feeding in shallow water areas where fertility is more abundant and aquatic wetter.
(1) Peng Zeyi has a wide range of water temperature adaptations and can feed and grow normally throughout the year. In the severe cold of the lunar month, more than 80% of individuals have I to II degree of intestine in the intestine. Even in ice-cold bodies, Peng Zeyi can live well. When the water temperature reaches 38°C, it does not affect it. survive. Its optimal growth temperature is 25-30 °C. Within this temperature range resistance, Peng Zeyi ingested food with the fastest growth rate. The growth period is from April to November in the Yangtze River basin, of which the fastest growth rate is from August to September.
(2) Peng Zeyu has a strong ability to adapt to adverse environments. In addition to its wide adaptation to water temperature, it also has strong endurance to physical and chemical factors such as pH and low dissolved oxygen in water bodies. The breeding and promotion test proved that Peng Zeyu is suitable for aquaculture in various water bodies, and is particularly suitable for growth in waters with fertile bottoms and rich benthic organisms.
(C), food Pengze eating a very wide range of food, with the amount of food organisms in the water there is a change in the number of omnivorous fish. In the natural waters, Peng Zeqi can use zooplankton and phytoplankton as food, but also feed on benthic flora and fauna and organic debris. The type of food varies according to its individual size, season, environmental conditions, and the dominant population in the water.
After 2 to 3 days after filming, Pengze’s fish fry rely on absorbing its own yolk as a nutrient. The larvae began to actively ingest zooplankton (such as small rotifers, small larval larvae, copepods, etc.), phytoplankton, and organic debris; juveniles and adult fish that were 4-6 cm in length, except Still taking organic detritus as the main feeding target, it also feeds on aquatic insect larvae, epiphytic algae, and young leaves and shoots of aquatic vascular plants.
In artificially cultivated ponds, Pengzeyu summer fish can be fed with soybean milk, wheat bran, feed powder, cakes and artificial feed. At the same time also eat the natural food in water.
Peng Zelu is a fish that feeds all year round, and its ingestion intensity follows the law of feeding of warm-water fish. In the spring, summer and autumn seasons, the intensity of feeding was greater (in the autumn, it was the maximum), and in winter, as the water temperature decreased, its feeding intensity gradually weakened, but the critical water temperature that Peng was eating was slightly lower than that of other carp species. The water temperature was 11 Below <RTI ID=0.0>C,</RTI> individuals with higher ingestion intensity (grades III to IV) can still be seen.
(IV) Growth Peng Zeyu is a large carp, known for its fast growth and large individuals. Common individuals weigh more than 250 grams, and the largest known Pengze louses are 4 kg and 6.5 kg, respectively.
In natural waters, Peng’s body growth and weight gain were the fastest in the year of birth, reaching 16.6 cm and 127.9 g respectively. The weight gain of the 2nd instar fish is still faster, which is 50.61% higher than that in the morning. The 4th instar fish still maintains a growth rate of 29.85% over the previous year.
After breeding, Pengze was cultured in ponds and had a faster growth rate, which was 56% faster than before breeding. In artificially cultivated water bodies, the growth of Pengzeyao is largely influenced by factors such as the density of the fish stocks, the stocking species, and the abundance of bait. Under normal circumstances, the pengyu fish fry which was bred in that year, after growing for about 6 months, has an average body length of more than 19 cm and a body weight of about 200 g.
(5) Breeding habits Peng Zeyi can lay eggs in rivers and lakes, as well as spawn in ponds. He can either reproduce naturally or produce artificially. 1 Peng Zeyi of the winter (12 months) can reach sexual maturity. Female sexually mature individuals weigh more than 170 grams and have a maturity factor of 14.8%, ie, 14.8 grams of ovaries per 100 grams of fish body weight. The relative amount of eggs was 151 eggs/g body weight. When entering the wintering period, the ovary develops to the beginning of III-VI. Male sexual mature individuals have a smaller body weight than female individuals, and their sexual maturities range from 4.3% to 4.67%. When they enter the overwintering period, the testes can develop to N stage, and sexual maturity is earlier than that of females. ~ 2 months. In the natural population, the female to male ratio is 10 to 12:1. Peng Zeqi is a normal diploid (2n=100) sexual reproduction group, producing sticky yellow eggs, which is a type of multiple egg production. Eggs are fertilized by single sperm. The resulting eggs are sticky when they come into contact with water and they swell with water. They stick to the aquatic plants or suspended in water on the basis of the stickiness of the egg membrane. The diameter of the newly produced eggs is about 1 mm, and the diameter of the eggs after water swelling Up to 1.5 mm. The fertilized eggs are colorless and transparent, and the unfertilized eggs are milky white and will soon dissolve. When the water temperature is 18 to 20°C, it takes about 53 hours and 15 minutes from fertilization to hatching. When the incubation temperature is 16 to 17°C, the incubation time is about 143 hours. The newly hatched larvae exit the membrane, and the larvae emerged completely. About 3 mm long. Often attached to his place, he swings intermittently and begins feeding. The time from hatching to horizontal swimming is approximately 50 hours. From March to July each year, Pengze's breeding period and April's breeding season. In the southern region, generally after mid-March, when the temperature of the water rises to around 17°C, Peng Zeqi begins to lay eggs. When the water temperature rises to 20 to 24°C, the breeding activity is most prosperous. Rainfall, microfluidic, and hot climate have a role in inducing spawning during the breeding period. Under natural conditions, Peng Zeyi likes flowing water, and especially prefers to breed eggs in micro-flowing water with a certain degree of turbidity and in dense shallow water areas.
Osaka's biological characteristics
First, the morphological characteristics
(a) The body color of Osaka osmanthus is silver-white and each fin is silver gray and black.
(B) Although the body is long, but the body is laterally flat and high, the front back hump slightly humpback type. Abdomen without edges. The head is small and the kiss is blunt. Small mouth, end position. No need to quarrel. Pupils are smaller and their eye diameter is 2.25 times that of the pupil. Eye wide spacing. The tail is relatively slender and the caudal peduncle is longer than the caudal peduncle. The starting point of the dorsal fin is closer to the snout than to the tail base. The outer edge of the dorsal fin is slightly concave. The pelvic fin origin is opposite to the starting point of the dorsal fin and does not reach the anal fin. The starting point of the anal fin is closer to the base of the pelvic fin than to the base of the pelvic fin, and the third hard thorn of the anal fin is thick. The caudal fin bifurcates and the ends of the upper and lower leaves are rounded. The anus is located before the starting point of the anal fins.
First, living habits Osaka Sakamoto live in the water, in the upper, hi cluster. The water temperature has a wide range of adaptability and can survive well in the water bodies in China. It does not need wintering and avoiding the cold. It has strong tolerance for low dissolved oxygen in water bodies. Osaka's oxygen consumption rate is lower than that of northeastern silver storks and wild pheasants, but higher than that of heterotrophic silver gilts. From the time when the test showed a serious floating head to the total duration of death due to hypoxia and suffocation of all test fish, the Osaka pigs could endure for 11 hours (asphyxiation point of 0.2 mg/g) and the wild horse had only 7 hours of endurance ( The asphyxiation point was 0.23 mg/l. It can be seen that the Osaka wolfberry is more tolerant to hypoxia. Osaka 鲫 can tolerate the ability of low dissolved oxygen, which is beneficial for pond feeding management and transportation.
Second, the food of Osaka Stork can live in a variety of bodies of water, the ability to adapt to food, can change the type of food with the number of food organisms in the habitat, including feeding artificial feed. When Osaka fishes in the juvenile stage, it mainly eats zooplankton (including small cladocera, colisters, and rotifers). When Osaka's carcass reached 8 centimeters in length, it began to feed mainly on phytoplankton but also ate organic detritus and artificially fed commercial feed. It also consumed a small amount of zooplankton. However, as Osaka's carcass length reached 31 cm, it almost ingested phytoplankton in the water, and the intestine was filled with dark green algae. In Japan, Mizuhiko Mizuno monocultured or codfishes with squid in eutrophic ponds and eutrophic ponds. The result was an interesting phenomenon: in oligotrophic ponds, lack of phytoplankton, feeding Is a large number of cladocera and benthic diatoms; when Osaka wolfberry monoculture in an eutrophic pond, due to the blue and green algae in the water as the dominant population, it will be the main food (90% of the food in the intestine) (Left and right); Although Osaka Stork lives in another eutrophic pond, it is mixed with squid. At this time, Osaka oysters are the main food rotifers and benthic diatoms, while squid are all ingested phytoplankton. It can be seen that the food habits of Osaka oysters will change with changes in environmental conditions in order to survive. In addition, according to a report from the Sun Yat-sen University in Guangzhou, at a water temperature of 24 to 27.5°C, Osaka Sakai (testing a body weight of 9 to 13 grams, with a total of 86 tails) was able to ingest silky algae, the Spirogyra. The trace test and autoradiography of the fish body confirmed the ingestion and digestion and utilization of Spirogyra in the Osaka salmon species. The ingestion rate (percentage of daily fish consumption in the fish body) for the Spirogyra was 1.85% to 4.00%. The actual digestion and absorption rate of Spirogyra is 48.49%. Spirogyra is widely distributed in natural water bodies. It not only has strong fertility and fast growth rate, but also absorbs artificially applied fertilizer in ponds to make the water thin, which is very unfavorable to the growth of grasshoppers and carps feeding on plankton. Sometimes it is also possible to encroach on the fry and cause death, causing a harmful factor in fish farming. To some extent, Osaka Stork can ingest digestive water, which not only harms the benefits but also contributes to the growth of other fish. At the same time, it is also an excellent example of "biological control" without pollution.
In summary, it can be seen that the food habits of Osaka Stork are very broad and omnivorous. Therefore, according to its food habits, it is necessary to lead the breeding of its own. For example, during the fry incubation period in Osaka, a large number of zooplankton must be cultivated for their food intake. When the osaka osaka gradually grows up to the rearing stage, the combination of fertilization and feed should be paid attention to in the water body to ensure that both the rich natural feed and the artificial feed containing various nutrients are included in the water body. In order to meet the needs of its growth in a good ecological environment, this is a successful experience in raising Osaka Osaka.
Second, the salmon fish breeding
(1) Peng Zeyi's breeding Peng Zeyi's broodstock requires a mature individual with typical characteristics of robustness, no injury, and no injuries. When the broodstock was selected from the fish of the year that was reared in the fingerling pond and the wintering of the fingerlings and the pond after November of that year, Pengzeyu of more than 200 grams per tail was collected and placed in the clear pond. In winter, the ponds with deeper water levels are overwintering and serve as spawning broodstock for the second year. During the wintering period (December to February of the following year), when the weather is fine, the concentrate should be fed in an amount of about 2.0% of the fish's body weight. After the spring, the male and female penguin should be fed in a timely manner to prepare for prenatal training and strengthen management. The overwintering of broodstock and the quality of prenatal culture directly affect the amount of broodstock, maturation coefficient, spawning rate and emergence rate.
In the breeding season, the ovaries of female broodstock are obviously contoured, the abdomen is flat and soft, the anus is red and swollen and congested, and the abdomen is often pressed to squeeze out the granules. The fish has more smooth mucus. Male broodstocks have "stars" appearing on the head and chest. The skin on the surface is rough and the abdomen is not contoured. Milky white semen flows out of the lower abdomen. In the non-breeding season, the male has a relatively long pectoral fin, and the tip of the pectoral fin can reach the starting point of the pelvic fin. Female pectoral fins are fan-shaped and shorter, and do not reach the starting point of the pelvic fin. The pond with an area of ​​0.04 to 0.07 hectares of spawning ponds served as a good spawning pool for Pengzeya broodstock. 7 to 10 days before oxytocin production, clear ponds, disinfection, killing of wild fish such as squid, and cleaning of water and other debris are performed. Then, about 70 centimeters of water is used for spare. When the water is injected, it should be filtered with a dense sieve to prevent the wild fish from entering the spawning pool. The water lettuce, palm, or willow roots were sterilized with (10 to 20) X10-6 potassium permanganate or 1/5000 malachite green, and a fish nest was placed in the pond. Male to female ratio (1 ~ 3): 1 release broodstock, water temperature under natural conditions, 17 °C to death, broodstock estrus and breeding their own eggs, will be attached to the fertilized eggs from the nest of another hatch hatching fry. This method is simple and easy for small-scale production. Its main disadvantage is that the spawning cycle is long and the emergence time is inconsistent. It is not convenient for the next stage of feeding and management.
In order to achieve the same specifications of batch fry, artificial ovulation can be performed. Male and female broodstock, according to the proportion of (2 - 3):1, when the water temperature reaches above 17 °C, a single injection of HCG (chorionic hormone) 800-1200 units per kilogram of female fish, or LRH-A (luteinizing hormone Releasing hormone analogs) 20 to 30 micrograms, or according to instructions for use of the drug. The male injection dose is halved. The injection site is usually at the base of the pectoral fin without scales. The injection time is preferably from 3 to 5 pm. The effect time is 9 to 16 hours (water temperature 18°C ​​to 20°C), and the total spawning time lasts 6 to 20 hours. Estrus chase is often below the surface of the water, and the sound of water waves and blows is small. The brooded brooding brood of the pengwa broods will be eaten by the brooded broodstock. After the broodstock spawns, the broods filled with fertilized eggs should be immediately transferred to the hatchery for hatching.
(b) The Osaka Stork has a reproductive weight of 250 grams or more, a strong physique, no injuries, and two-year-old Osaka oysters can be used as breeding broodstock. The broodstock should be cultivated before spawning. In addition to feeding good feed, it is also necessary to pay attention to the management of good water quality, so that the phytoplankton in ponds can be maintained at a certain level to ensure the nutrients required for gonad development. During the breeding season, sexually mature males and females can pair themselves in natural waters or ponds and spawn. Therefore, clear ponds and disinfection work must be conducted before the breeding ponds are hatched. Like other salmon breeding, the fish nests should be prepared and the broodstock should be put in. Male and female broodstock, according to the ratio of (2 ~ 3): 1 matching group, and then given microfluidic stimulation, usually the broodstock can naturally spawn, if the pro-fish into the pool, the injection hormone aphrodisiac, spawning will be more smooth and synchronized. The artificial propagation and hatching techniques of Osaka Stork are similar to those of Peng Zezheng. Refer to the operation.
(3) The seedling culture techniques of carp seedlings for breeding several carp species are similar and are presented here. The newly hatched larvae cannot swim because they are very tender and small, and they are in the "nest stage" stage. Don't rush to remove the fish nests. After 2 to 3 days, the yolk of the larvae disappears, and the larvae are inflated. When the fry can swim in peace, the fish nest can be removed and the cooked egg yolk or soybean milk can be fed in time. Generally, soybean milk is fed 2 or 3 times a day. Every 0.07 hectare of water uses 3 to 4 kilograms of soybeans every day. After 10 days, some concentrated feeds and top-up manure and other organic fertilizers are added. In order to promote the growth of fry, during fry cultivation, it is necessary to inject new water 2 to 3 times, so that the water depth is maintained at 1.0 meters, and each time water is injected 5 to 10 cm. After 15 days of cultivation, the fry can be up to 2.0 to 2.6 cm in size. At this time, soymilk can be stopped. It can grow to 3.0 to 3.5 cm in 20 to 25 days and enter the next stage of cultivation. In fry cultivation, as the fish grow up, the density of the fish in the pond is often too high, which is not conducive to the growth and management of the fry, so it needs to be cultivated in a timely manner. Usually 7 to 10 days after the larvae have been raised, the fry is carefully and slowly raised in a cage (fish) cage or box, and moved to a pre-prepared fry pool after a few hours. The cultivation method is the same as above. Each 0.07 hectare of water surface stocking density of 150,000 to 200,000. When the eel fry reaches 3.0-3.5 cm, the size of the fry of the four large populations in most parts of the south is about 1.5-1.8 cm. At this time, 3.0-3.5 cm of fry can be pressed. A density of 2000-3000 tails/0.07 hectares was housed in a fry breeding pool for the four-masts. After 15 to 20 days of feeding, the size of the fry of the four home fishes reaches 2.5 to 3.5 cm, which can be transferred to the pond for breeding or sale. The size of the carp seedlings is up to 5.0 cm or more. This type of fry has Facilitating the development of Peng Zeyi's fish into adult fish.
Third, carp adult fish breeding
(I) Pond farming Eel adult carp is cultured in ponds. It mainly adopts four farming methods: polyculture in adult fish ponds, stock raising in fish ponds, broodstock pool raising and pond main breeding.
1. In the adult fish pond, polyculture of squid, and green, grass, alfalfa, alfalfa, alfalfa, pupa, alfalfa and other varieties of polyculture. Large-scale species should be stocked. The time for stocking should not be late, that is, winter stocking is better than spring stocking. Stocking density is 150 to 250 tails per 0.07 hectares of water. The stocking specifications and quantity of other fish are determined as needed. The requirements for aquaculture ponds are not high, generally 0.1 to 2 hectares, and ponds with a water exploration of 1.5 meters or more. At the bottom of the pool, 10-15 cm thick silt is the best. The cleaning, disinfection, and basal fertilization of ponds were performed according to conventional methods, and the survival rate was about 80%. After 200 days of feeding, the majority of individuals weighing 200 grams or more are considered to be the vast majority. The output of each 0.07 hectare of water is more than 20 kilograms.
2. The main pond raising requirements of the carp are 0.1 to 0.2 hectares, with a depth of 1.5 meters or more, and 10 to 15 centimeters of mud at the bottom of the pond. The ponds with domestic sewage behind the houses have better effects on the main carp. . One week before the stocking of fish, it was disinfected with quick-lime clear ponds, and water was injected 2 to 3 days after disinfection. During the water injection, the grid was used to filter at the inlet to prevent wild fish from entering the pool. 5.0 to 6.5 cm per 0.07 hectare of water main fish wintering species of 1500 or 2,000 large-scale fry hatched in the current year, with about 40% (600 to 800) of grass, cockroaches and cicadas wintering species . Restocking time should be sooner rather than later. The daily feeding of concentrate feed is the main method, combined with the water quality of fertilization culture. The annual feed amount of concentrate feed is equivalent to about 2.5 times of Peng Zeyu's estimated production. With fixed-point feeding, the daily feeding amount depends on the growth of the fish body, the weather, the water temperature, and the ingestion intensity of the fish, and fertilizes or refills the new water according to the water quality. Under the general management level, 200 kg of squid with an average weight of 150 g/swallow and about 200 kg of grass, squid, and squid were obtained in the same year. As the proportion of high-quality fish is higher, its net profit is also higher than other farming models.
3. The fry pool sets up squid. Can be set in the green, grass, alfalfa, clams, cockroaches, clams and other fish fry pool, rather than suitable for nesting in trout, tilapia fish species pool. The area of ​​nesting ponds requires 0.1 to 0.2 hectares, and the depth of water is 1.0 to 1.5 meters. The pond cleaning, disinfection, and basal fertilization are the same as the conventional method. The carp is nested in other fry pools and can only stock the fish species hatched in that year. It is advisable to have a stocking time sooner than usual. Normally, when the fishery species hatched in the main breeding year is transferred into the wintering species, the fish species hatched in the year should be released immediately; the stocking size should not be small, and the stocking density should be 150 to 220 tails per 0.07 hectare of water. The number of stocks, specifications, and combinations of fish species that were hatched in other years were determined based on production needs and specifications of the outlet ponds. Because it is a bottom fish, the eel seedlings generally do not affect the living space of the fish species and can fully utilize the water space. Therefore, the fish species hatched in the year were reared in the fry pool, which basically did not affect the stocking densities of the main fish species and the specifications of the outlet ponds; Therefore, there is basically no need to increase funding and feed input. Under normal feeding and management conditions, carp seedlings are nursed in fry pools and raised for 150 to 180 days. The water size at the end of the year can reach more than 200 grams. Each 0.07 hectare of water surface can increase the amount of adult fish from 25 to 40 kilograms.
4. The broodstock breeding pond sets up squid. In southern China, the artificial breeding of domestic fish is generally completed from mid-May to the end of May. The gonads of the postpartum broodstock are in the recovery period. In order to restore the body strength of the broodstock as soon as possible and promote the development of gonadal, the ponds are mostly intensively managed. In addition to broodstock breeding and other fish, this fish pond can accommodate up to 200 tails of 5 to 6 centimeters per 0.07 hectare of water. The broodstock is reared in a broodstock breeding pond and the stocking time is usually carried out at the same time as the broodstock. The culturing (breeding) method is performed according to the conventional method of raising the broodstock. Bred broodstock should follow its law of gonad development. The broodstock nursery ponds generally cannot be caught in dry ponds at the end of the year, and can only be completely arrested when the broodstock is used for prenatal strengthening. After feeding for 250-300 days, 25-45 kg of carp can be obtained per 0.07 hectare of water surface, and the average body weight is more than 200 grams.
(B), rice field farming carp fertile soil, irrigation is convenient, good water retention and fertilizer performance of rice fields can be farmed carp, generally double-season rice farming, single-season rice due to short time, it is difficult to reach the adult fish breeding specifications. Before the fish is released, depending on the size of the paddy field, the source of the water, the water inlet and outlet, etc., the field hoe, fish slip (fish pit), and fish ditch are excavated in the field. Tianshun requires solid and watertight. The area where the fish slides varies from place to place. Each 0.07 hectare of water is between 3 and 5 m2, with 20-30 meters more than the average. The average area of ​​the fish is about 5%, and the water depth is 0. .8 meters can be, depending on the shape and size of the fish ditch, depending on the shape and size of the field, there are "a" shape, "10" shape, "shi" shape, "å…" shape and "kou" shape and other forms. Rice-field cultured squid can be cultivated or mixed, and the stocking size of 5.0 to 6.5 cm is better. One week after the transplanting of the early rice, the fish species will be released and 250 to 500 fish fry per 0.07 hectare. Without feeding, more than 20 kilograms of carp can be harvested after the fall, with an average tail weight of about 100 grams. If some concentrate is used, 0.07 hectares of carp can produce more than 35 kilograms. Daily management is the same as that of other fish. To encourage the use of organic fertilizers to increase the richness of organic matter in paddy fields so as to facilitate the growth of carp. At the same time, do a good job of anti-escape equipment to prevent the top water to escape.
(3) Small-sized reservoirs and lakes Breeding squid Small lakes and reservoirs rich in natural food and water quality are suitable for stocking squid, and larvae that use feeding or fertilizing or semi-intensive breeding lakes and reservoirs have better effects. Within 1 to 3 years, lakes and reservoirs for dry lakes or dry storage, and stocking squid, can generally achieve very good results in increasing production and income. Due to the relatively large water surface of lakes and reservoirs and the predation of more fish, in order to increase the survival rate of earthworms, large-scale fish species should be stocked as far as possible, and stocking density should be 20-50 per 0.07 hectare. Stocking time can be both winter and spring. The high-yielding lakes and reservoirs that are released every year for fishing can increase the stocking amount of squid, and can be standardized and managed according to pond farming squid technology. In lakes with rich natural foods and fertile water, the growth rate of carp is even higher than the speed at which it grows in ponds. In that year, the weight of a carp was 250 g or more, and the lakes and reservoirs of dry lakes or dry lakes for 2 to 3 years had a body weight of 500 grams or more accounted for a considerable proportion.
(D), cage culture of carp use of reservoirs, lakes and other large water surface for intensive production of cages, do not occupy the land area and the surface of the pond, is a new breeding mode of the attempt. As large reservoirs, lakes, and other large water surface, making the cage inside and outside the water body can be fully exchanged, so the dissolved oxygen is sufficient; the second cage cultured fish activity is small, less energy consumption, which are conducive to the growth of carp. The specifications of cages generally require an area of ​​16 to 28 m2 and a height of 2 to 3 meters. The size of the mesh depends on the specifications of the stocking species, and large meshes are used as far as possible without increasing the size of the fish. Exchange of water inside and outside the large box. It is better to use 3X3 polyethylene mesh wire as cage material. Mesh cages are often installed in floating and fixed ways. The distance between the boxes is 2 to 3 meters and the row spacing is about 20 meters. Determining the location of the cage setup takes into account the following factors:
(1) Choose slow water flow. The area where the water level is stable, sheltered from the sun, and has a flat bottom is preferably a sandy bottom with a water depth of 5 to 6 meters.
(2) The surrounding environment is required to be rich in vegetation, water quality is fertile, and dietary food is abundant.
(3) Industrially polluted waters cannot be used as a cage setting site.
Cage cultured carp generally adopts single-culture mode and can also be used with a certain proportion of plutonium, alfalfa and alfalfa, generally controlled within 3% to 5% of the total output. A 50 to 200-sold eel fry with a size of more than 5 cm per square metre should be stocked, and the fish in the same cage must be fully loaded at one time. Stocking specifications must be neat, otherwise the size of the fish will become more and more disparate. Catfish farming in cages must be baited. It is better to feed artificial compound feed, semi-floating or sinking granular feed. The bait formula can refer to the formulation of the squid cage culture and the protein content can be slightly lower than that of the squid bait. Feeding a small number of times, is the principle of feeding cage fish. Each time the amount of bait was eaten with 90% of the bait before it was leaked out of the cage, the least amount of bait that was finally put into the diet was the criterion for determining the amount of each feeding. Daily feeding 4 to 6 times, no feeding at night. Other aspects of daily management are no different from conventional cage fish farming. After 180 to 200 days of feeding, the average body weight of the fish can reach more than 200 grams, and the output per square meter can reach 8 to 25 kilograms.
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