1. Cultivation of parent fish Parent fish can be cultivated in special ponds or in interplanting. Ponds cultivated in special ponds require convenient water intake and drainage, fresh water, high dissolved oxygen and neutral or slightly alkaline. When the adult fish are harvested at the end of each year, California bass with good physique, large size, good body color, no damage and no disease are selected as backup parent fish, which are put into a special pond for cultivation, and 300 ~ 400 bass are stocked per mu. During the cultivation period, small fish and shrimp are mainly fed, and the daily feeding amount is about 3 ~ 5% of the parent fish's weight. Every once in a while, some eggs-holding shrimps can be put into the pond to breed young shrimps for the parent fish to prey on, so as to keep enough bait in the cultivation pond to meet the nutritional needs of the gonad development of the parent fish. California bass can't tolerate low dissolved oxygen, and it is easy to float. When the water quality of the pond becomes thicker and the transparency is less than 20 cm, it is necessary to inject new water in time. In the hot and thunderstorm season, oxygen should be increased frequently, and the floating head of the parent fish will delay the gonadal development. In winter, the parent fish pond should be regularly flushed with clean water to keep the water fresh, which is beneficial to gonad development. Starting from February, you can start fishing and choose mature parent fish for artificial reproduction. Intercropping, that is, nesting California perch parent fish in grass carp parent fish pond, because grass carp parent fish pond generally has good water quality and high dissolved oxygen, and some wild fish and shrimp will be brought in while injecting new water and feeding aquatic plants, which happens to be the bait for California perch parent fish. Generally, 5 ~10 groups should be set in each pond, so it is not advisable to have too many. In winter, California bass should be caught and concentrated in a special pond for overwintering management. The above two methods of cultivating parent fish have their own advantages and disadvantages. The advantages of special pond cultivation are relatively centralized, easy to manage, the gonad development of parent fish is neat, and the breeding and spawning time in the next spring is relatively consistent. The disadvantage is that the source of feed is difficult. The advantage of interplanting culture is that the feeding cost is low, and the wild fish in the pond can be used as bait; The disadvantage is that the gonad development of parent fish varies from early to late, and it is difficult to lay eggs in a short period of time.
There are obvious differences between male and female in mature California bass parent fish. The female fish's abdomen is soft and swollen, the outline of the ovary is obvious, the upper and lower abdomen are uniform in size, the abdomen is upward and concave in the center, and the anus of the genital hole is reddish and slightly prominent. The male parent fish gently squeezes the abdomen, and milky semen flows out, which can be dispersed by itself in the water. From the appearance, mature individuals, which is big, healthy and lively, can be selected for artificial propagation.
Step 2 lay eggs and hatch
(1) Before the spawning season comes, the spawning pond should be prepared according to the production scale. The soil pond on the slope with sandy bottom is ideal, with an area of1~ 2 mu. Some stones and bricks should be piled around the pond, and some aquatic plants should be planted in the pond to prepare the parent fish for nesting and attachment before spawning. The slope ratio of the pond ridge is 1:2 or 1:3, which makes it easy for parent fish to dig their nests and is not easy to be washed down by wind and waves. The spawning pond covers an area of less than 5 mu and the water depth is about 1 m, and 20 ~ 30 pairs of parent fish are put in each mu. Parent fish should keep the pond and the surrounding environment relatively quiet after entering the pond. After a few days, it can be found that there are many fertilized eggs attached to the fish nest guarded by male fish around the pool, and the fertilized eggs can be fished out and washed for artificial incubation. General fish ponds with fresh water can also be used as spawning ponds after being disinfected by quicklime cleaning and exposure.
(2) Artificial induced spawning Under the condition of natural or normal artificial pond culture, in the reproductive season, the parent fish can generally mature, and can lay eggs and discharge sperm smoothly without artificial induced spawning, thus completing the fertilization process. However, when we need to spawn California bass in a planned way, we need to use the commonly used fish oxytocin to artificially induce spawning, but the fertilization rate of the fertilized eggs is lower than that of natural spawning. Moreover, the effect of parent fish on oxytocin is longer.
When artificial spawning is carried out, the selected parent fish are paired according to the individual size 1: 1 and injected with hormones to induce spawning. The oxytocin can be used in carp pituitary gland, and the dosage is 5 ~ 6 mg per kilogram of female parent fish, which is injected twice, with the first injection dosage of 15% of the total amount, with the interval of12 ~14 hours, and the rest; The male parent fish is injected with 2mg per tail, and the female fish is injected once during the second injection. The commercially available chorionic gonadotropin can also be mixed with the pituitary gland of common carp. The dosage of one injection is 300 units of hormone and 3 mg of pituitary gland per kilogram of female parent fish, and the dosage of male parent fish is halved. Thoracic injection Pay attention to the dosage of hormone, otherwise the overreaction of foreign protein will affect the physiological function of parent fish, resulting in death or blindness.
(3) Oviposition and Incubation Because the spawning effect of California bass lasts for a long time, when the water temperature is 22 ~ 26℃, it takes18 ~ 30 hours after hormone injection to estrus and lay eggs. First, the male fish keeps butting against the female fish's abdomen with his head, and when the estrus reaches its climax, the male and female fish's bellies are close to each other to lay eggs and ejaculate. The parent fish that laid eggs stood still around stop for a minute, and the male fish swam close to the female fish again. After several times of stimulation, the female fish went into estrus and laid eggs again. California bass is a type of multiple spawning. In a spawning pond, parent fish can be seen spawning for1~ 2 days continuously, and the whole spawning process will be completed on the third day.
California bass eggs are nearly spherical, and when they are produced in water, the egg membrane quickly absorbs water and expands, showing stickiness, and often adheres to aquatic plants or pond walls, stones and bricks in fish nests. The fertilized eggs remain in the spawning pool to hatch. When the water temperature is 20 ~ 22℃, the incubation time is 31~ 33 hours, and when the water temperature is17 ~19℃, it takes 52 hours to hatch the fry. Artificial incubation method, according to the experiment, it is better to hatch in still water in a cement pool with micro-running water or in a cage with fresh water and high dissolved oxygen. The density of fertilized eggs is generally about per square meter 10000.
The newly hatched fry are protected by the male fish. But when the fry grows to about 2 cm, it can be swallowed by the male parent fish. Therefore, within a few days after the fry hatch, the parent fish after spawning should be caught and put into the parent fish pond for intensive cultivation, and the parent fish should be cultivated in the spawning pond. Or pick up the fry with a hand-made net and cultivate them in another pool. If fry are cultivated in a pond with parent fish, they will often be swallowed by parent fish. Fish pond polyculture
Under the condition of not changing the main cultured species in the original pond, raising an appropriate number of California bass can not only remove wild fish, shrimp, aquatic insects, benthos, etc. from the fish pond, but also increase the income of California bass and improve the economic benefits of the fish pond. This is a method of killing two birds with one stone. Generally, 30 ~ 40 fish species are stocked in each mu of fish pond without additional feed, and15 ~ 20 kg of adult California bass can be harvested at the end of the year. If the fish pond conditions are suitable and there are many wild fish, the mixed culture density of California perch can be appropriately increased, but carnivorous fish such as snakehead and eel should not be mixed at the same time. In addition, don't mix California bass in fry ponds or ponds with fish culture, so as not to hurt small fish species.
Attention must be paid to polyculture: ① the pool water should not be too fat; ② The stocking amount should be appropriate; (3) At the initial stage of polyculture, the specifications of main cultured species are more than three times larger than those of perch; ④ California perch, especially juvenile, is sensitive to pesticides, so attention should be paid to the prevention and treatment of fish diseases and the application of pesticides.
Fish pond main cultivation
1. The fish pond requires sufficient water, convenient irrigation and drainage, no water leakage, water depth above 1.5 meters, good water quality, no pollution, ventilation and light transmission, and loam as the bottom material. The area should not be too large, and1~ 2 mu is appropriate. Equipped with an aerator.
2. Generally, the stocking density is 2000 ~ 2500 California bass fry per mu, and 3000 ~ 4000 bass fry can be put in fish ponds with good conditions and equipment. Appropriate mixed culture of silver carp, bighead carp, grass and bream helps to clean up feed residue and adjust water quality.
3. Feeding California perch requires high protein, which requires that the feed contains 45-50% crude protein, and the following feeds can be fed in production.
(1) eel feed;
(2) the mixed fish pulp is mixed with proper amount of peanut bran, bean cake and corn flour;
(3) Compound feed, the formula is: fish meal 60%, raw bran 10%, wheat flour or corn flour 25%, yeast, vitamins, minerals and additives 5%.
Feeding is usually done once in the morning and once in the afternoon. When the water temperature is 20 ~ 25℃, the daily feeding amount is10 ~15% of the fish weight, but it should be flexibly controlled according to the fish's feeding, activity and weather changes.
4. Daily management
(1) patrol the fish pond every day to observe the activities of fish schools and the changes of water quality, so as to avoid the pond water being too turbid or fertile, and the transparency should be 30cm. Find problems in time and take measures to solve them.
(2) Strictly prevent pesticides and public hazards from flowing into the pond, so as to avoid the death of pond fish. In particular, young fish are extremely sensitive to pesticides, and very little dose will cause the death of fry in the whole pond, so we must pay great attention to it.
(3) The feeding amount should be appropriate, and it should not be too much or insufficient. At the same time, it is necessary to avoid using a single feed for a long time, and vitamins and minerals should be added to the feed to maintain normal nutritional requirements.
(4) Grading and thinning in time, once every two months, stocking fish of the same specification in the same pond to avoid eat small fish. Separate rearing should be carried out in the morning with good weather, and it is forbidden to raise in hot or cold weather.
Koike intensive care
California bass farm requires the following conditions: sufficient water source and good water quality; The terrain is slightly inclined, which is beneficial to drainage; Sufficient sunlight and good ventilation; Loam is the best substrate, and sand can be spread on it; Pollution-free dirt and sewage enter. The area of the aquaculture pond should not be too large, and it should be 50 ~100 square meter. Earth embankment or cement embankment can be used, but the bottom of the pond should be soil. You can also use idle eel ponds or other pools. Irrigation and drainage outlets should be set opposite each other, and an escape device should be added. If the stocking density is high, an aerator should be installed. If the stocked fry are small, a fishing net should be added to the pond surface to prevent bird damage. The stocking amount of fry depends on the management level and environmental conditions, generally 30 ~ 40 fish are stocked per square meter. If the water quality is good, the water source is abundant, and there are perfect aerobic facilities, the stocking quantity per square meter can be increased to 50 ~ 60. Fish species stocked in the same pond require the same specifications and are lively and disease-free. Can't mix big and small, in order to avoid cannibalism, big fish eat small fish, causing unnecessary losses. Feed feeding is best to feed the feed with high protein content, and the more suitable feeds are eel feed, offal fish, etc., and various artificial compound feeds can also be fed. Before feeding, the eel feed should be stirred and extruded into granular materials with appropriate amount of water, and the miscellaneous fish should be cut into pieces with a meat slicer. Freshly stocked fry should stop feeding for one day because of moving shock, and start feeding a small amount of the original feed the next day, and then start mixing other feeds after gradually increasing to the normal feeding amount. So that the fry can get used to feeding. Generally, it is fed twice a day in the afternoon, and the feeding amount should depend on the weather, water temperature and fish intake. When the water temperature is 20 ~ 25℃, the total daily feeding amount is10 ~15% of the total fish in the pond. When the water temperature is too high, too low or the wind and waves are heavy, the feeding amount should be reduced as appropriate. Feeding management refers to the management of fish pond main breeding. net-cage culture
Intensive culture of California bass with cages can also achieve excellent economic benefits, and cages can be set in reservoirs, lakes, rivers and ponds.
Location of cage preparation and placement: the cage is a Lux-type double-layer covered cage with a specification of 4m× 4m× 2m and a mesh of 2.5cm.. The net row floating frame is made of Phyllostachys pubescens, with double rows of Phyllostachys pubescens overlapping on the main road and single row of Phyllostachys pubescens on the auxiliary road, and the cage spacing is 2 meters. The sinker is a cement block with a weight of 1 kg, with 8 sinkers in each net, and the bamboo raft is fixed with 6 cement piers, each weighing 60 kg (the area of the cage is set as required, and it is generally appropriate to use16 ~ 30 square meters). The cage can be set in reservoirs, lakes, rivers and ponds, and the cage can be moved according to the change of water level to keep the water depth of the cage above 3 meters. California bass has strong resistance to diseases and is less sick when cultured. However, sometimes fish diseases occur due to improper custody. Common fish diseases and prevention methods are as follows.
Needle worm disease
It is caused by the parasitism of needle worms. The parasitic part is mainly the tail end of dorsal fin or ventral fin base, and the affected part is often accompanied by congestion, so the sick fish has a slightly poor appetite. The treatment is to catch the sick fish, pull out the needle worm and disinfect the wound with medicine. Accelerating the change of water can prevent the spread of the disease.
Water mold
It is mainly due to the infection of water mold when there is a wound or scales fall off. There is white wool in the affected area, and the sick fish loses appetite and eventually dies. The treatment method is to disinfect with malachite green solution of 1ppm, once a day 1 time, and at the water temperature of 20℃,15 ~ 20 minutes each time. The higher the water temperature, the shorter the time, and the longer the time required for low water temperature, which can be cured for 3 ~ 4 days.
Blindness
The diseased fish's eye membrane turned white and turbid, which led to the loss of vision and inability to eat, and finally died. The cause of the disease is eye injury when fishing, so you should be careful when operating, especially to prevent eye injury.
Bone flexion disease
The spine of the fish is abnormal and bent. The cause is unknown, which may be caused by abnormal division during hatching, and there is no treatment for it. This form of fish grows slowly, so it is not suitable for breeding. It should be selected and not mixed when it is released. Cantonese-style baked bass
Raw materials: California bass 1 strip (about 750g), green pepper and red pepper 5g each, garlic10g, chopped green onion 5g, appropriate amount of pepper and salt, Gillette powder100g, wet powder 5g, clean egg white 20g and egg yolk/kloc-0.
Method: Clean the perch and remove the fish, leaving the original bone. Cut the oblique knife inside the fish into "double-flying" pieces for later use. Add salt 1 g, egg white and wet powder to fish fillets, mix well and pat Gillette powder. Add refined salt 1 g to the original fish bones and fish heads, mix well with egg yolks, and pat with dried raw flour. Heat wok to 2 10℃, add fish bones and fry until golden brown, then put them on a plate, then fry the fish fillets until light golden brown, take them out at the ripe degree, recover the remaining oil in wok, then add garlic, pepper and chopped green onion to saute, then put the fried fish fillets, cook wine, sprinkle with pepper salt and mix well, and spread them on the plate. Roasted perch
Ingredients: small perch 2 treaty 4 10/0g, salt 1 2 tsp, soy sauce 1 tsp, Chili powder12 tsp, seed powder12 tsp, sugar12 tsp.
Practice: the bass is peeled and cleaned, and then opened into a cake from the middle piece. Ginger and garlic are ground into a small amount, mixed with seasonings, evenly applied to the fish and tasted for 20 minutes. Preheat the oven to 220 degrees, spread tin foil on the baking tray, brush the tin foil with oil, put the fish juice on the baking tray, brush the oil on the surface and put it in the oven. Put the middle layer, bake for * * * 18 minutes, take out the soup after 5 minutes, and move to the upper layer in the last 5 minutes. Perch meat is high-protein meat, rich in vitamin A and vitamin B, nourishing the liver, kidney, spleen and stomach, and also having curative effect on cold and cough, eliminating phlegm and relieving cough. It is rich in various trace elements, such as calcium, magnesium, zinc and selenium.
Perch can also treat fetal movement disorder, hypogalactia and other diseases. Eating perch for expectant mothers and pregnant women is a nutritious food that not only tonifies the body, but also does not cause obesity due to overnutrition. It is a good product for strengthening the body, enriching the blood, invigorating the spleen and benefiting qi, and benefiting the health.
There is more copper in the blood of perch, which can maintain the normal function of nervous system and participate in the function of key enzymes in the metabolism of several substances. People who lack copper can eat perch to supplement it.
Nutrient composition table
Calories (kcal) 105 thiamine (mg) .03 calcium (mg) 138
Protein (g) 18.6 riboflavin (mg). 17 magnesium (mg) 37
Fat (g) 3.4 nicotinic acid (mg) 3. 1 iron (mg 2
Carbohydrate (g) 0 Vitamin C (mg) 0 Manganese (mg) .04
Dietary fiber (g) 0 Vitamin E (mg) .75 Zinc (mg) 2.83
Vitamin A (μ g) 19 Cholesterol (mg) 86 Copper (mg) .05
Carotene (μ g) 1.5 potassium (mg) 205 phosphorus (mg) 242
Retinol equivalent (μ g) 76.5 sodium (mg) 144. 1 selenium (μ g) 33.06