The artificial culture of the fragrant fish began in Japan, China's Zhejiang Province has been tested, Hebei Province has been successfully cultured, Taiwan Province is more prevalent.
Farming site selection: the success or failure of the scented fish mainly depends on the water source, water quality, bait, management and other conditions. Farming site should be selected in the water supply sufficient flow, generally to reach the flow of 27 liters per second, the annual water temperature above 13 ℃, PH value between 6.5-7.8, bait rich and pollution-free areas. Northern areas should have overwintering facilities.
The design of the breeding pool:
(1) the size of the pool: according to the water source and water volume, generally 100-300 square meters per pool is more appropriate.
(2) the structure of the fish pond: round fish pond culture is the best, without dead ends, but also easy to focus on the dirt in the central drainage near the timely discharge, to keep the water quality fresh. The perimeter of the bottom of the pool to the center of the pool should usually maintain a 1/10-1/15 incline. When the fish pool area of 100 square meters, the thickness of the pool wall should be 15 centimeters, water depth of 60-90 cm, the bottom and walls of the pool with stone or concrete masonry, so that it is easy to epiphytic natural diatoms, increase the unique aroma of fragrant fish.
Stocking density and growth: when there is enough water, an average of 400 fry can be stocked per 3.3 square meters, and the growth rate of scented fish is related to the breeding conditions and management, and the commercial specification is 80 grams.
(3) Bait and feeding methods
Formulation: fish meal 25% animal protein powder 5% chicken meal 4% soybean meal 10% rice bran 15% alfalfa 5% wine lees 8% vitamins 15% solid fat 6% inorganic salt mixture 4% coarse corn meal 10%
Feeding methods:
Spreading method. The number of feeding is mainly based on the stocking density of the fry, developmental stage and environmental factors such as water temperature, water quality and water quantity. It is observed that scented fish should be fed more in the morning and evening. The amount of bait in the dissolved oxygen is sufficient, the water temperature is 17-22 ℃ for 20% of the weight of the fish, if the temperature is lower than 17 ℃ and the dissolved oxygen is low should reduce the amount of feeding. (1) Fish fry into the preparatory work before stocking
In stocking should be checked, maintenance of facilities, and in about 15 days before the release of pre-feeding, so that the walls of the pool full of diatom growth before releasing the fry.
(2) Fish species selection and transportation
The fragrant fish is a rare species, artificial fry only in Zhejiang, Hebei and several other nurseries are sold. Fry transportation can be carried out by car for long-distance transportation, water temperature 17-19 ℃, the density of survival rate of up to 98% or more; short-distance transportation density can be increased.
(3) the management of the initial stocking of fish fry
Fish fry in the pool before the release of the first disinfection bath, so as not to bring viruses into the pool, the amount of antibiotics in the bath is about 1/50,000-1/10,000 of the amount of water. On the day of stocking into can bait, baiting amount depends on the health of the fry and the weather, after a few days, baiting amount gradually increased to about 15%.
Generally, fry weighing 5-6 grams are stocked in mid-March and can reach commercial size by early June. The bait coefficient is 2.5-3. The main attention in the management of rearing is paid to the following aspects:
a, feed more fresh, high nutritional value and rich in animal protein bait to produce larger size of the commodity.
b, often pay attention to changes in water temperature, scented fish do not tolerate low temperatures, when the water temperature is low, it is easy to cause indigestion, when possible, can be raised to the optimal water temperature or increase the bait, but avoid feeding bait containing more fat.
c, the fish sometimes also eat each other, you need to patrol the pool often, observe the feeding and activity of the fragrance, in order to adjust the amount of bait in a timely manner.
d, observe whether the activity in the pool is normal and appetite changes, check whether there is any disease to avoid loss.
The success of fish farming depends mainly on the environmental factors and the level of the management system.
New technology of pond intensive culture of scented fish
The scented fish is an excellent aquaculture species, with strong adaptability, short food chain, fast growth, short cycle, high economic value, can be used as reservoirs, lakes and streams to increase the object of culture, but also in the ponds and nets in the land-sealed aquaculture.
The construction of pond culture ponds should be chosen in the vicinity of streams, rivers and reservoirs with abundant water sources, power and electricity, convenient transportation, fresh water quality, abundant dissolved oxygen, ph value of 6.5-7.8, and no discharge of pollutants.
The bottom of the pool should be paved with a large number of pebbles in the gravel is good, can also be used in all the cement pool, so that it is easy to attach the natural diatoms, adding the unique aroma of fragrant fish. Water inlet opened in the center of the bottom of the pool, and by the bottom of the pool buried pipe discharge. In order to prevent the escape of fish, the drainage should be set up to stop the fish net, the water surface to the embankment surface should be retained for a distance of 30 centimeters, in order to prevent fish from jumping out. The center of the water level in the pool is 1 to 1.2 meters, and the depth of the water level at the edge of the pool is 0.6 to 0.8 meters.
The length of the fry is generally 3 to 4 centimeters. Stocking season, Ningbo, Zhejiang region in February each year began to release batches of fry, the latest should be the end of April. Fry stocking density varies according to the amount of water, water temperature and other changes. Rectangular pool stocking of fry for 100-300 tails / per square meter, round pool for 200-400 tails / square meter, these pools in addition to the use of flow-type intensive aquaculture, it must be turned on day and night oxygenator, oxygenation, in order to ensure the survival rate of the fish fry. Before the fry enter the pool, they need to be sterilized in a medicinal bath to prevent bacteria from being brought into the pool.
The fragrant fish in the natural environment to feed on the benthic algae; in artificial rearing, the adaptability of the copper material is wider, such as mysis shrimp, fish meal, silkworm pupae, snail meat, chopped fresh miscellaneous fish and shrimp and wheat flour, potatoes, soybeans, rice bran, greens and so on, like to eat. Fry period can be used to fertilize the breeding of plankton for its intake; when the body of the fish reached more than 50 grams can be cast into the eel feed, and with 20% to 30% of the green fodder. Feeding to master the principle of a small number of meals, the daily feeding for the fish pool about 4% of the total weight of the fish, divided into 3 to 4 times / day feeding. As the fragrant fish has the habit of competing for food, so the bait should pay attention to uniformity, so that the fish body specifications grow uniform and tidy. The use of compound feed, should be soaked in water for about 20 minutes, to be softened before use, the effect is better.
The growth rate of the fragrant fish is relatively fast, usually weighing 2 to 4 grams of fry, feeding one month weight up to 10 grams, two months weight up to 25-40 grams, three months up to 50-60 grams, four months up to 70-100 grams (commercial specifications in the more than 60 grams).
The good or bad management of fish ponds has a great deal to do with the growth of scented fish. In the spring when the water temperature is low, it is easy to cause fish indigestion, must add vitamins "fish essence" and other nutrients, summer high temperature season should pay attention to prevent heat and cooling, when the water temperature is more than 26 ℃, should strengthen the water to increase oxygen and take shade and other cooling measures. In the late stage of aquaculture due to the increase in fish body, so we need to increase the amount of water exchange and injection of smooth water, especially in the input of bait, it is necessary to increase the amount of water, in order to prevent the lack of oxygen caused by the flooding of the pool. In the culture of fish disease prevention and control should be strengthened.
The common diseases of the aromatic fish are:
Water mold disease
This disease usually occurs in spring and autumn when the water temperature is 15℃～20℃. Attention should be paid to the fry handling operations to avoid fish injuries as much as possible, on the sick pool per cubic meter of water with methylene blue 2 grams to 3 grams of water to the whole pool sprinkled.
Enteritis
Enteritis. The disease can occur all year round. Feeding should be more fresh, high nutritional value and rich in animal protein feed, rainy weather when the water temperature drops appropriate to reduce the amount of feeding, to prevent enteritis disease. Treatment can be added to each kilogram of feed haloperidol 0.5 grams, 5 grams of food mother of life, mixing feeding, 3 times a day, feeding for 3 days.
Hemorrhagic disease of liver and kidney
This disease mainly occurs in the high temperature season from June to September. Sick fish head, abdomen congestion, anus red and swollen, liver and kidney hemorrhage, death in large quantities. The method of prevention is to take timely cooling measures, and reduce the amount of feed feeding and so on. After the onset of the disease, chlorine-containing disinfectant can be used to hang the bag, and at the same time, internal administration of Valium Bao, Cod Liver Ning, Multivitamin, etc. (according to the instructions). Fragrant fish sales of the golden season is generally May to August, farmers should try to avoid stocking the pond or raised to winter, when the fish weight of about 100 grams can be caught on the market in order to obtain a more satisfactory market price.
Parasitic diseases:
I. Rotifers
1. Symptoms
Generally parasitized on the surface of the body in the fry stage, and mostly on the gills in the large size. Fish body a small amount of parasitism does not show symptoms, serious infestation of the skin, fins, gills, wheel worm with its gear ring abrasion scented fish body epidermal cells and gill filaments, fin epithelial cells, stimulate the fish body to produce a lot of mucus. Sick fish do not feed, swarms of wild swimming along the pond, jumping in the water, can make the gill filaments and body surface epithelial cells destruction, shedding, leading to bacterial invasion, resulting in a large number of fish deaths.
2. Prevalence and harm
The disease occurs throughout the country throughout the year, turbid water and organic matter in ponds are more likely to occur, the appropriate breeding temperature of 20 ℃ ~ 28 ℃, April to July is more prevalent.
3. Prevention and treatment
(1) Before releasing the fish in the pond, we can use 150 grams / cubic meter ~ 200 grams / cubic meter of quicklime or 10 grams / cubic meter of bleaching powder to thoroughly clear the pond. Because scented fish are sensitive to chlorine disinfectant, pay attention to the residual chlorine content after clearing the pond.
(2) Use "Fish Insect Cleaner" 0.3g/m3 to splash the whole pond, and change the water after 10 hours.
(3) with copper sulfate, ferrous sulfate (5:2) combination of 0.3 grams / cubic meter of the whole pool splashing, 12 hours after a large-scale water change, repeated every other day.
(4)Splash the whole pool with 5g/m3 neem bark decoction.
(5) Splash the whole pool with 1 g/m3 to 2 g/m3 potassium permanganate at night.
Two, small melon worm disease
1. Symptoms
Small melon worm parasites in the main parts of the body surface of the fish, sick fish skin and fins on the naked eye can be seen corridors clear, the size of 0.5 mm ~ 1 mm white dots of cystic cells, commonly known as the white spot disease. Diseased fish swim slowly, floating on the surface of the water, feeding poorly, away from the food court; severe disease fish body surface seems to be covered with a layer of white film, scales off, epidermal inflammation, localized necrosis, finlets are destroyed, was vesicular, respiratory function is impeded and died.
2. prevalence and harm
The disease is transmitted by the larvae of the cysticercus period, there is no strict selectivity of the host, and fish of all ages can be infected. The pathogen can spread with water flow and tools, and can also be transmitted to people through fish fry and fish species to make it spread. The suitable water temperature for the reproduction of small melon worm is 15℃～22℃.
3. Prevention and treatment
(1) Splash the whole pool with 20ppm～25ppm formalin.
(2) Splash the whole pool with methylene blue 1g/m3, and change into new water after 8 hours of drug bath.
Three, microsporidiosis
1. Symptoms
Infection of the initial period of no obvious symptoms, with the formation of cysts of the symptoms appeared, scented fish eyes, mouth, gills, fish muscle or viscera can be formed cysts, so that the surface of the body appearing tumor-like protrusions, the fish body curved deformation, and ascites, emaciation, and a variety of other diseases.
2. Epidemics and Hazards
The disease can cause epidemics in wild fish, and most of the disease is brought by fish species.
3. Prevention and treatment
Once infected with this disease, there is no treatment for scented fish, only the removal of diseased fish.
Four, triple worm disease
1. Symptoms
Triple worm parasites on the body surface, fins and gills of the fish, the optimal reproduction temperature of about 20 ℃, mainly by the eggs and larvae of the worm transmission, prevalent in the summer (May to September), especially in the rainy season and the hot days, the distribution of the very wide. When a large number of parasites, there is a layer of grayish-white mucus on the skin of sick fish, the fish body loses its luster, the fish swims abnormally and often jumps, the appetite is reduced, the fish body is thin, and the respiration is difficult.
2. Epidemics and hazards
Most of the aromatic fish parasitized by this worm will be mildly anemic, and the incidence and deaths are more frequent from May to August.
3.Prevention and control
The whole pool is splashed with 20ppm to 30ppm formalin dilution.
V. Fingerling disease
1. Symptoms
Fingerling is mainly parasitic on the gills of the fish, and the symptoms are not obvious when it is mildly infected. When a large number of parasites are parasitized, the fingerling will hook the gill tissues of the hosts with its anchoring hooks and small hooks on the edge of the gills, and then worm around the gills to destroy the gill filaments of the epidermal cells, which will stimulate the gill filaments to secrete excessive mucus, preventing the fish from respiration and generating anemic phenomenon. The disease is prevalent in summer, and at the beginning of the disease, the fish are slow to feed, and after a few days, they swim rapidly and furiously until they die. The diagnosis can be confirmed by microscopic examination.
2. Epidemics and hazards
Transmitted mainly by eggs and larvae, it is prevalent in the summer, especially in the rainy season and hot days, and often causes a large number of deaths if not treated in time.
3. Prevention and control
The use of 20ppm ~ 30ppm formalin diluted solution of the whole pool splashing effective.
Six, cormorant disease
1. Symptoms
Cormorant parasites in the body surface and gills of the fragrant fish, sucking the blood of the fragrant fish, so that the fish body gradually thinning, in the feeding everywhere in the mouth and jaws to stab the fish's skin, resulting in a lot of wounds and then infected with microorganisms caused by death. The venom secreted by the fish when it sucks blood with its mouth spines has a stimulating effect on the fish's body, which makes the fish extremely uneasy in the water, swimming and jumping wildly in a hurry.
2. Epidemics and hazards
Watercress disease is widespread in China, occurring throughout the year, especially in the summer is more serious.
3. Prevention and control
(1) before stocking fish ponds with lime with water to clear the ponds, kill the water in the trematode adults, larvae and egg masses.
(2) Use 30 ppm formalin dilution bath for 12 hours for 3 days.
Let the fragrant fish smell
The fragrant fish, a valuable small economic fish species, is a traditional feature of Ninghai Teal Creek in Zhejiang Province, but in the 1960s, due to the blocking of the creek to build reservoirs, indiscriminate fishing and the deterioration of the water quality environment and other reasons, the fragrant fish is nearly extinct. However, people here made great efforts to save the resources of Ninghai Eider River's fragrant fish, so that this valuable local specialty was saved and regained its light.
Ninghai Eider River, Zhejiang Province, once there is such a fish, fish body narrow and flat side, head small mouth pointed, so look at the ordinary fish, the selling price is not low, in the local area can be sold to forty or fifty dollars, it also has a nice name called fragrant fish.
Experts: the fragrant fish itself on the surface of the body exudes a fragrance then steamed after steaming after eating it tender meat more oil and fresh and this fragrant fish into the fragrant fish dried dried products such as the color of gold can be presented to some guests everywhere.
The fragrant fish smells good and tastes even better, was once Emperor Qianlong's offerings, known as the "king of freshwater fish". Ninghai, Zhejiang Eider Creek Village, where the climate is pleasant, quiet environment, Eider Creek is the village of a stream through the sea, more gravel in the water, the water is clear and fast-flowing, algae congestion, the original is a good place to live and feed on the fragrant fish, is now long gone fragrant fish.