1. Selection and feeding of parent carp
Selection criteria of 1: good body shape, strong activity and no damage, and the ratio of body length to height is 3: 1, which has typical variety characteristics. The female fish is at least 2 years old and weighs 1.5kg, while the male fish is better than 1kg. Carps in the first sexual maturity and aging period are not suitable for parent fish because of their poor egg production and egg quality.
2. Gender identity
Non-breeding season: the female fish has a wide body, a high back, a small head, a large and soft abdomen, a small and round pectoral fin and ventral fin, a flat or slightly prominent cloaca with radial folds; The male fish has a long and narrow body, a big head, a small and hard abdomen, a large and sharp pectoral fin, a slightly concave anus and no parallel wrinkles.
Breeding season: the abdomen of female fish is soft and round, and the anus and reproductive pores are large and slightly red; The abdomen of male fish is small, gill cover, chest and ventral fin have obvious accessory characteristics of "idolization", anus and genital hole are sunken, not red and swollen, and milky semen flows out when the abdomen is lightly pressed.
3. Feeding management
(1) Feeding: parent fish breeding pond 1-2 mu, with water depth of about 1.2 m, sheltered from the wind and sun, convenient for water injection and drainage, and per mu 150-200kg. In artificial reproduction, males and females should be separated to prevent them from mating and laying eggs by themselves. Disinfect with quicklime or bleaching powder before placing.
(2) Management: Strengthen parent fish cultivation and feed high-protein feed such as bean cake, silkworm chrysalis and fish meal. In recent years, some manufacturers have developed parent fish feed, which is rich in vitamins such as ve, which can promote development and improve anti-stress ability with good results. At the same time, attention should be paid to regulating water quality, supplementing fresh water frequently, keeping running water and stimulating gonad development during feeding.
Second, spawning and hatching
1. Timing of labor induction: When the water temperature rises and stabilizes above 16℃, labor can be induced. Usually, during the Qingming period to Grain Rain, after the cold wave, when the temperature rises steadily, induced labor can be induced.
2. Mode of induced labor
(1) Natural spawning is a very common way because of its small investment and scale.
Oviposition pond: a pond with an area of 0.5- 1 mu and a water depth of 1.2 m, which is convenient for water injection and drainage. Fish can be released in a week after being disinfected with quicklime.
Artificial fish nest: used to attach fish eggs. Choose soft, tough, non-toxic and non-perishable materials, such as pine branches, brown sheets, polyethylene sheets (woven bags) and poplars. , and wash, tie and disinfect (0.3‰ formaldehyde or malachite green) before use. Straw is not suitable for fish nests because it is perishable.
C Incubation pond: it can also be used as a fry breeding pond, with a small area (1-2 mu) and little silt. There is a disinfection pond with a water depth of 1 m ... The entrance and exit should be filtered with dense mesh to prevent impurities from entering the pond and fry from escaping.
D, polyculture and spawning: polyculture 35-30 groups of mature parent fish according to the male-female ratio of1:1.5, and slowly add fresh water. At the same time, pull 1-8 iron wire on the water surface, and hang artificial fish nests on the iron wire (or break bamboo in half and put it in the middle). Usually, each parent fish group should have 4-6 fish nests.
E management: Generally, eggs are laid from 22: 00 to 9: 00 on 2-3 days, so every afternoon, check and clean the fish nest, move the fish nest with eggs into the incubator, and replenish new fish nests. If it is not easy to lay eggs after polyculture, the water level can be lowered to let the sun shine, and ve or micro-flow water can be added to the feed to stimulate. In order to ensure the uniformity of fry, the eggs of the day should be hatched together, which can also prevent the number of blind eggs from increasing due to the adhesion of fish eggs.
(2) Artificial induced labor: more common in fish farms.
Oxytocin injection: 600- 1000 IU of artificial chorionic gonadotropin (HCG) or 30-50 micrograms of luteinizing hormone analogue (LRH-A) is used per kilogram of female fish, or the dosage of male fish is reduced by half. Generally, it is injected into the chest of pectoral fin root at 6 pm on sunny days, and then moved into spawning pond, and fresh water is added for half an hour. After the water temperature 18℃6- 15 hours, you can estrus and lay eggs (the higher the water temperature, the shorter the action time, and vice versa).
B spawning and fertilization: after spawning, the parent fish can spawn in the pond by themselves, and the method is the same as (1). If the eggs are collected artificially, they can be picked up before the fish's estrus climax, wiped off the water from the fish with a towel, squeezed into a dry porcelain basin, and quickly squeezed into the semen, stirred with feathers to make it fully fertilized, and then the fertilized eggs are evenly spread on the fish nest and hatched in an incubator. Or debonding with talcum powder solution and hatching with running water. When the water temperature is 16-22℃, seedlings can emerge in 3-5 days.
3 management:
(1) Natural incubation: 300,000-500,000 fertilized eggs should be put into each mu of pond, and the eggs of the same day should be put together to ensure that the fry specifications are neat. Special attention should be paid to prevent water from becoming moldy. Fish nests with eggs can be soaked in 0.3‰ formaldehyde or malachite green in advance. (2) Debonding incubation: The key is to adjust the water flow speed, so that the fish eggs are suspended in the water without sinking. At the same time, it is necessary to prevent the sand window from blocking. When the fry hatch, the flow rate is slightly reduced to prevent the fry from physical consumption caused by excessive water flow.
Improving the hatching rate is the key to artificial propagation. The main reasons that affect the hatching rate are sudden change of weather, poor water quality, low dissolved oxygen, fish eggs being parasitized by mold, etc., which should be prevented as far as possible.
ⅲ seedling cultivation
Cultivation of summer flowers and standard fish species.
First, summer flower cultivation
1 pond preparation: choose 1-2 mu, with a water depth of 0.8- 1.2 m and little silt, and clean and disinfect it according to the conventional method.
2 Fertilization (also called "fertilizing the pond"): 7- 10 days before the fry enter the pond, fermented manure can be applied, such as 150-300kg/ mu of pig manure, cow dung (about 5 stubbles) or 5- 10kg/ mu of inorganic fertilizer (chemical fertilizer, ).
3. Release the fry: before releasing the fry, empty the net with a dense mesh net to remove wild impurities, or release 50-80 cheap silver carp fry to test the water. After it is proved that everything is safe, the fish can be released.100-250,000 fish/mu.
Clear water into the pool: fry are directly put in, and no base fertilizer is applied. This method is weak and the survival rate is low, because there are few rotifers in the palatable bait in water.
5 management:
(1) Timely feeding: After the fry enter the pond, they grow very fast in the first few days, and there is often a shortage of natural bait. Pay attention to feeding. Commonly used soybeans are scattered and sprinkled with cooked egg yolks for feeding. Every day, 2-4 kilograms of soybeans and 3-5 cooked egg yolks are ground into slurry and immediately sprinkled and fed, and concentrated on the water surface several meters near the pool. You can also splash filtered fresh pig blood every three days. Soymilk can be eaten directly by young, and it can also enrich water quality and natural bait. At present, there are also fish fry materials circulating in the market, which are shaped like microcapsules or powder. It can be fed in 6 ~ 8 minutes, which can not only supplement food, but also induce fry to grab food, thus promoting the development of digestive tract and helping to improve survival rate and strong seedlings.
(2) Topdressing and water management: topdressing once every three days to keep rotifers in the water at a high level. You can also extract some water from the fat fish pond every day and add it to the fry pond, which can not only increase the natural bait for the fry, but also prevent the occurrence of bubble disease caused by too much well water. 1/3- 1/2 Change the water every week.
(3) Careful observation: patrol should be strengthened in the process of fry cultivation. Observe its activities, eating, growth, water quality changes, invincible hazards, diseases and so on. At the same time, fry should be divided into pools in time to prevent uneven specifications caused by excessive density. If necessary, we should also draw nets to exercise fry and enhance endurance.
Two-specification fish species cultivation: after summer flower cultivation, the length and weight of fry have increased many times, and the adaptability has also been enhanced. The change of eating habits has shown the characteristics of varieties, and people begin to like concentrate, so they should make a smooth transition to compound feed as soon as possible. The feeding method is as follows:
1 monoculture method: Choose 2-4 mu of disinfection pond with water depth of 1- 1.5 mu, put 3,000-6,000 fish in each mu, and feed it with compound feed or mixed feed of bean cake, silkworm chrysalis and fish meal, and the feed protein requirement is above 35%, with 8-65,438 fish per day.
2 polyculture method: carp summer flowers are mixed with other fish species, which can be mainly carp or supplemented by carp. If carp is the main food, feed should be strengthened; If silver carp is the main species, the water quality can be cultured properly; If grass carp is the main species, carp should be released less.
3 Feeding management
(1) Feed early, the earlier the opening, the earlier the growth starting point, and the better the growth. We should strive for a smooth transition to feeding with full-price compound feed as soon as possible.
(2) Pay close attention to the early stage (25-30 days) when fish species grow very fast, and their body length and weight increase rapidly, so they need more feed. At this time, feeding should be strengthened, and the feeding rate of some fishermen exceeded 10% during this period.
(3) Feeding should adhere to the "four fixed" of quality, time, position and quantity, and feed according to the feeding rhythm of fish species.
(4) Do a good job of "three patrols and four inspections" in daily management, grasp the climate, fish situation and illness, keep the fish growing rapidly, and inject water regularly to prevent floods and escapes.
Ⅳ Adult fish culture
Carp is widely distributed and cultivated in many ways, such as ponds, cages, running water, fences, rice fields, ponds and so on. Pond culture is introduced here, and readers can refer to related books for other breeding methods.
First, the carp-based farming model.
The size of the fish pond is not limited, but the feed coefficient of the big pond will be high, and the water depth is 1.2- 1.5 meters. Carp species of different sizes can also be released in stages and batches, which is convenient for round catching and round releasing.
This model is mainly fed with compound feed, with crude protein above 30%, 4-6 times a day, and the feeding rate is 3-8%. In addition to the traditional eight-character key points of "water, seed, bait, density, mixing, wheel, prevention and management", there are new "communication" strategies: superior seed, concentrated material, good water and management. Although the first six words of the new "cross" policy are similar to the old "eight characters" experience, the new period should contain new contents, or strengthen or supplement them. The emphasis here is on refined management, which means that the feeding managers can't ignore any link. Even if it is a penny's input, it is necessary to calculate its output. Only in this way can we ensure high efficiency.
The second is the stocking mode with carp as the breeding object.
1. Grass carp or Megalobrama amblycephala as the main model: grass carp or Megalobrama amblycephala 60%, carp 15%, silver carp and crucian carp ***25%, which is suitable for areas with good water resources and plenty of forage.
2. The patterns of silver carp (50%), carp (15%), grass, bream and crucian carp (30%) are suitable for the fatter water body.
3. Channel catfish and channel catfish account for 60%, carp for 10% and silver carp for 30%.
4. Basic model of crucian carp: 60% of crucian carp, 0/0% of carp/kloc, 0/0% of grass carp/kloc and 20% of silver carp.
V. Prevention and treatment of fish diseases
First, acne: symptoms: the early body surface of the sick fish has milky white spots, and the condition is aggravated. This spot spreads all over the body. There is milky white paraffin-like hyperplasia on the epidermis of the affected area. When the proliferation grows up, it will fall off by itself, and soon it will grow new, which will affect the growth and even kill the fish. Pathogen: caused by herpes virus. Epidemiology: it mainly harms carp over one year old, and it is frequently entrusted in autumn, which is not easy to cause dead fish and mainly affects growth. Prevention and control: ① The fish pond is thoroughly disinfected, and the fish species are strictly disinfected before entering the pond. ② Soak in cyanomycin solution for 3 days.
Second, the disease: symptoms: inflammation of the back skin and muscle tissue, and then ulceration into abscess, with the feeling of edema by hand. Abscess inflammation, congestion, congestion, fin erosion into a brush (fishermen also call it broom fin), severe intestinal bleeding and inflammation. Pathogen: Aeromonas furunculata. Epidemiology: it is more common in polyculture fish ponds with silver carp as the main species. There is no typical season. It can happen all year round. Prevention and control: ① Thoroughly disinfect fish, water and ponds; ② Pay attention to prevent fish from being injured; ③ Take ciprofloxacin 80mg/kg feed orally and disinfect it with 1ppm bleaching powder water for 3 days.
Third, rotten gill disease (commonly known as aconite plague): symptoms: traveling alone, eating less, dark body color, especially black head. The gill filaments are rotten with silt, the inner epidermis of the gill cover is congested, and the middle epidermis is corroded into a round or irregular transparent window (also called skylight), and the gill filaments are rotten. Pathogen: Myxococcus Fisch. Epidemiology: it harms many kinds of fish, and the water temperature is 20-32℃, which is the most prone to outbreak. This disease is rare in winter, and it is often combined with skin redness and intestinal diseases. Prevention and treatment: ① Disinfect water with bleaching powder before onset, especially in high temperature season; ② Oral erythromycin 100mg/kg feed or enrofloxacin 80mg/kg feed; ③ Spray oxytetracycline 0. 1ppm in the water of disinfection pool.
4. Scale disease: Symptoms: The surface of the diseased fish is rough, and some scales (mostly on the back of the fish) open outward like pinecones, so it is called pinecone disease; Translucent or bloody exudate accumulates in the scale capsule, which makes the scale stand up, so it is also called scale disease. Press the scales gently with your fingers, and the exudate will gush out from under the scales, and the scales will fall off. Red ulcer, exophthalmos and abdominal swelling were formed at the desquamation site. Finally died in 2-3 days. Pathogenic water-borne polar trichomonas punctata. Epidemiology: The disease mainly harms carp, crucian carp, grass carp and silver carp. The disease has two epidemic periods: one is the spawning period of carp, the other is the wintering period of carp; However, the main popular season is from the end of April to the beginning of July. The mortality rate is 45%, and the highest can reach 85%. Prevention and treatment: ① Fish injury is the main cause of this disease, so be careful when pulling the net to prevent fish injury. ② Disinfection of fish, water quality and pond. ③ Feed oxytetracycline or chlortetracycline 50-80mg/kg.
Five, enteritis: symptoms: commonly known as rotten intestinal plague. The abdomen of the sick fish is swollen and erythematous, and the anus is swollen and protruding like a volcano. In severe cases, the fins will be corroded and broken. When you cut open the fish belly, you can see that there is water in the abdominal cavity and the intestinal wall is congested and inflamed. In light cases, only the foregut or hindgut is red, and in heavy cases, the whole intestine is purple. There is generally no food in the intestine, which contains a lot of yellowish mucus or blood pus. Pathogen: Aeromonas punctata. Epidemiology is very common in grass, carp and crucian carp, with a high mortality rate, with a general mortality rate of about 50%; The disease can appear two obvious epidemic seasons in a year, May-June and August-September. This disease is often accompanied by bacterial gill rot. Prevention and treatment: ① sulfaguanidine treatment: per 10 kg fish, use 1 g on the first day, and reduce the dosage by half on the second to sixth day. ② When treating enteritis complicated with gill rot, the whole pond was sprayed with 2-3ppm gallnut, and furazolidone bait was continuously fed for 6 days, with the dosage of 65438±000kg fish 65438±000mg； per day; When the condition is serious, the first dose of furazolidone is doubled. ③ Feed 50 grams of garlic to fish every 10 kg, once a day 1 time for 3 days.
6. Dermatomycosis: Symptoms: At first, when the mold was parasitic, the naked eye could not see anything abnormal in the sick fish. When you see it with the naked eye, the mycelium has invaded the wound of the fish and grown inside and outside. When the injury is deep, the mold can penetrate into the muscle inward, spread into the gap between the tissue and the cells, and grow outward into a mycelium similar to gray cotton wool, so it is called "long hair or white defect". When fish is stimulated, it secretes a lot of mucus, and the sick fish is restless, moves abnormally and rubs against other objects. In the future, the fish will be overburdened, the affected muscles will rot, the sick fish will move slowly, lose appetite and eventually die. This disease often occurs during the incubation of fish eggs. On the injured fish eggs, hyphae can be seen invading the egg membrane, and hyphae outside the egg membrane gather in the water, so it is called "oofilaria". Parasitic fish eggs are also called "sun seeds" because their hyphae are radial. Pathogens: Myxomycetes and Myxomycetes. Epidemiology: the disease occurs all year round and is prevalent in all fish culture areas in China. This mold has no strict selectivity to the host, and all kinds of raised fish can be infected from fish eggs to fish of all ages. The hatching season of fish eggs usually begins in spring, when the water temperature rises to about 65438 08℃, and the water temperature at this time is most suitable for the growth and reproduction of water mold. After the parent fish lays eggs, the water mold first grows and reproduces on the unfertilized fish eggs, and under suitable conditions, it continuously forms dynamic sporangia through asexual reproduction. A large number of zoospores are released to infect fertilized eggs, so the germinated mycelium can often be observed under the microscope. At the initial stage of infection, the embryonic development of infected fish eggs can still proceed normally, but in the later stage, when the hyphae enter the inside or outside of the egg membrane and are completely surrounded, and the dead eggs are seriously infected with water mold, the embryonic development of fish eggs will die halfway. Especially in rainy days, when the water temperature is low (15 ~ 20℃), it is easy to occur and spread rapidly, resulting in a large number of fish eggs dying from infection with water mold. Prevention and treatment: ① Using quicklime to clean ponds in fish ponds can reduce the occurrence of this disease. ② Try to be careful in the process of fishing, handling and stocking, so as not to hurt the fish, and pay attention to the reasonable stocking density, which can prevent the disease. (3) Do not collect injured fish as parent fish; When parent fish enter tang qian, it is not necessary to apply% malachite green ointment or appropriate amount of sulfanilamide ointment to the fish. ④ At the onset, 0. 1.5 ~ 0.2 ppm methylene blue can be sprayed in the whole pool. ⑤ Prevention of Aquaculture in Fish Eggs: First, try to improve the fertilization rate and control spawning in good weather conditions; Secondly, hatching eggs in fish nests with water can reduce or interrupt the chance of aquatic zoospores infecting fish eggs, and can obtain a higher hatching rate. ⑥ When the sticky fish eggs hatch in the pond, they can be soaked in 7ppm malachite green 10 ~ 15 minutes for two days, and then sprinkled on the water near the hatching frame with 70 ~ 100 ppm solution 15 kg every morning and evening until the fry hatch. ⑦ For fish eggs hatched by running water, malachite green solution is added every 6-8 hours. Until the fry hatch.
Seven, carp stupid disease: symptoms: there is no obvious change during mild infection. In severe cases, intestinal obstruction can be seen, which can cause inflammation and anemia of intestinal mucosa and occasionally death. Pathogen: Carp tapeworm. Epidemiology: It mainly harms carp and crucian carp, especially in April-August. Control: Trichlorfon was taken orally.
Eight, carp uterine nematodiasis (also known as red filariasis): symptoms: loose scales, congestion, inflammation and ulceration of muscles around scales. It is easy to cause water model complications. Under the parasitic scales of the insect body, there are red and purple irregular patterns. You can see the red insect body by lifting the scales. Pathogen: Carp Uterophilic Nematode. Epidemiology: It is harmful to adult carp. In winter, worms parasitize under scales, but they are small and do not show diseases. When the water temperature warms in spring, worms grow faster, leading to fish diseases. Prevention and control: ① Lime is strictly disinfected to kill larvae. ② Scrub the affected area with iodine spray or 1% potassium permanganate, or soak it in 2% salt solution for 10 ~ 20 minutes.