(i) Biological characteristics
1. Habitats are widely salty fish that can grow in the ocean, fresh water, and brackish water. It is also a wide-temperature fish, suitable temperature range 1 ~ 38 °C, growth temperature 13 ~ 30 °C, the best temperature for water 25 ~ 27 °C. The required amount of dissolved oxygen in water is more than 2 mg/l, but more than 12 mg/l is prone to bubble disease. In love with swimming against the water, the skin and intestine have respiratory function. Under the temperature of 15°C, the skin is kept moist, and skin respiration can sustain life.
2. Food habits and growth habits are ferocious and gluttony. In the natural environment, small fish, shrimps, benthic animals, and aquatic insects feed on food. When there is insufficient food, they will be similar to each other. Seedlings are mainly eaten with clams and leeches. The wild cricket grows slowly and grows to 200 grams in two years. Artificial domesticated seedlings can be fed compound feed and grow fast. Some of the seedlings in the year could be grown into 170-250 grams of commodities, most of which reached the above specifications in the first half of the following year. After the short-term feeding of the same batch of seedlings, the size of the seedlings varies, and they need to be gradually divided and sparsely reared.
3. Breeding habits The genus is a migratory migratory fish that lays its eggs in the deep sea. The larvae swim with the currents to the mouth of the estuary along the flowing sea, back up into the fresh water for food and grow, and after sexual maturity, they swim to the deep sea for breeding. The newly hatched seedlings were scattered with the currents and gradually developed into willow larvae. One year later, they were close to the estuary and metamorphosed into white larvae (5,000 to 7,000 tails per kilogram). In freshwater, the color of white Tsai is increased to become T. nigra (about 1,000 tails per kilogram). At present, many countries have organized research on artificial reproductive technology and have not succeeded. All the seedlings needed for breeding depend on the seedlings that have been caught and taken to the coast and estuaries.
(ii) Transportation and transportation of seedlings Seedlings are generally planted under low temperature conditions to make the seedlings paralyzed, reduce their metabolism and increase their survival rate. More use of cage wet transport and packaging oxygenation transport two methods:
1. The cage-type wet transport method uses a wooden board to make a frame cage of 604,015 cm, and then uses a screen to cover the bottom, 5 to 6 cages and stack it up. The top one cage puts ice cubes, and the next few cages put the seedlings. Each cage is weighed at 1.5 kg or 2 to 4 kg. Dissolved ice water moistened seedlings. This method is simple to operate, low cost of transportation, but heavy equipment, only suitable for short-distance transport.
2. Packed oxygen transport method uses polyethylene double bag to add water, put into the seedlings, and transport with oxygen. External foam box or carton packaging, put 2 bags per box. Ice bags wrapped in plastic bags are placed between the bags for cooling along the way. This method can guarantee safe transportation within 24 hours, light and flexible, high survival rate, and low cost. The amount of ice carp and the amount of ice can be referred to the following table Carp loading and adding water to ice quantity 鳗鲡 Specification Each bagged amount of water Adds water to each bag Ice box (kg/kg) (kg) (kg) (kg)
5000 to 7000 tails 1 3
800 to 1200 tails 2 3 to 4
300 to 500 tails 3 4
100 to 200 tails 4 0.3 0.5
30 to 60 tails 6 0.3 0.5
3 to 6 tails 10 0.3 0.5
(3) Cultivation of Seedlings Cultivation of seedlings is the cultivation of white clams to small clams weighing 15 grams.
1. Breeding facilities The seedling culture season is mostly in the winter. The water temperature is low and the growth is slow. It is best to cultivate in greenhouses. This can effectively prevent water mould, accelerate the growth of seedlings and increase the survival rate. The area of ​​each cultivation pond is 50 to 100 square meters in the early stage, 100 to 200 square meters in the middle stage, and 300 to 400 square meters in the later stage. The water depth should be 0.5 to 0.6 meters in the early stage and 0.7 to 0.8 meters in the middle and later stages. The optimal water temperature is 28°C. If it is lower than 22°C, it is prone to outbreak of saprophytic disease. Breeding water temperature control in the 25 ~ 29 °C, the survival rate rate can reach 90% or more, when the seedlings about 20 to 30% to develop commercial products. Each pond has two 0.55-kilowatt waterwheel aerators placed diagonally. At the White Tsai Stage (within 7 days of entering the pool), it is best to use 0.3 m3/s of air compression pump to increase oxygen. Each installation of 40 bubbles of rock, one bubble stone per cubic meter of water, will ensure the dissolved oxygen in the water. 5 mg/L or more.
2. Seedlings are stocked and sterilized by salt bath or salt bath before stocking. Add 1 to 3 grams of methine blue, 2 grams of furazolidone, or 1 gram of furazolidide per cu.m. of water to make a drug solution; or soak for 1 to 2 days with 1.5% to 2% of salt water. To control aquatic mold, it can also treat edema disease of seedlings. The stocking density at the beginning of seedling cultivation is preferably 0.3 to 0.5 kg of seedlings per cubic meter of water, which will gradually spread as the seedlings grow.
3, tame food seedlings into the pool the first two days, the whole pool evenly fed fresh blisters, so that the seedlings have the opportunity to meet, eat at any time. From the third day to the fourth day, mainly feeding red worms around the pond, adding some water fleas properly, and taking care of individual frail larvae can also eat long and strong. Then, using the characteristics of seedling night light, a 40 watt electric bulb was hung over the feed table, and the seedlings were introduced around the table and taken to the table. It is also possible to shade the table above the table during the day to create an overcast environment where the seedlings are fed.
When feeding, attention should be paid to: 1 feeding mainly of red worms, most of which are placed on the food table, a small amount is distributed on the edge of the pool, and the poolside feeding amount is reduced day by day; the feeding amount on the 2nd is 20 on the weight of the seedlings. % ~ 35%, feeding in 3 times, taking food as a degree; 3 feeding aerator to stop, reduce interference.
After the seedlings cultivated the habit of concentrating on food intake, they gradually postponed the night feeding until the morning to the day. The shades set above the food table were gradually removed, so that the seedlings gradually adapted and finally they were able to feed freely in the sun.
4. Switching to compound feed When the seedlings normally take in food and can devour large individual leeches or red worms, they must gradually feed compound feed. First mix the leeches or minced worms with compound feed, add 10% to 15% of formulated feed on the first day, and increase it by 10% to 15% every day. After about one week, you can completely feed compound feed. Now.
The daily feed rate of compound feed is about 10% to 15% of the seedling body weight. It is fed twice a day, 60% at 7 to 8 in the morning, and 40% at 4 to 5 in the afternoon. The feed must be fully kneaded and mixed. , pay attention to moderate hardness, in order to facilitate seedlings feeding.
5, Gradually divide and sparsely cultivate seedlings into seedlings, and increase their body weight by nearly 100 cultures. Individuals are also uneven. Therefore, it is necessary to regularly divide sparsely, generally sparse once every 25-30 days. If the seedlings grow faster, they should be classified early and diligently. If individual individuals differ by more than one time, and small individuals are obviously at a disadvantage in feeding, they should also be graded. Before grading, the seedlings should be stopped for 12 hours. Feeding can be done within half an hour after the operation is completed. In fact, it is still fed twice a day. Classification should be timely and sparse, grading should be meticulous, and the same pool specifications should be neat. The first stage of sparse sapling is to be carried out 20 to 25 days after the arrival of the white larvae.
(d) Adult pupa raises glutinous rice cultivars weighing more than 15g into 170-250g, including Dianchi intensive culture, earthen pond cultivating and fish pond polyculture.
1. Dianchi intensive culture construction, masonry structure, drainage and irrigation facilities, complete supporting turtle ponds, high-density breeding, feeding compound feed, meticulous management, generally 1/15 hectares producing 2 to 3 tons, high yield 7 to 8 Ton.
1) The condition of the rearing pond is 500 to 1,000 square meters per pond, and the wall height is 1.2 to 1.5 meters. A complete drainage and irrigation system is required, and two impellers or aerators are placed on the other side, and two food sets are provided on the other two sides. .
2) The stocking densities depend on different specifications, ranging from 4 to 50,000 tadpoles weighing about 5 g per 1â„5 ha, 3 to 40 000 to 10 g, or 2 to 3 to 20 g. Millions, or 500 to 700 thousand, over 25 grams.
3) Feed agitation and feeding Feed mixing should be uniform and soft. Stir well and feed immediately. The feed pellets were placed in the food table and required 2/5 of the water surface. The daily feeding amount is 6% to 10% of the body weight of black flounder, 4% to 6% of small japonica species weighing 1 to 15 grams, and 3% to 4% of japonica species of 20 to 40 g, 50 The amount of ～100 grams of Chinese wolfberry is from 2.5% to 3%, and that of 100 grams of wolfberry is from 2% to 2.5%. In production practice, it is necessary to pay attention to the accumulation of experience and flexibility, and it is generally appropriate to eat in about 20 minutes.
4) Grading The sparsely grading should be done once every 30 days, so that the squid stocked in the same pool can be kept in regular specifications, and the stocking density in each pool can be adjusted in time. Gradually divide and sparse before the first stop feeding 1 to 2 days, replace the pool water, the implementation of in-situ water, so that the squid emptying the food in the stomach, re-election. During the sorting period, avoid catching squid by hand. Special fish sifter should be used, and the squid should be sprinkled with water to make the squid active and naturally slide across the fish screen. Care must be taken when handling and gentle movement to prevent damage to the fish. 2. The earth ponds are cultured with a strong pond foundation, sandy bottom mud, drainage and irrigation facilities, and a pond with power supply. A higher standard for newly-raised fishponds can also be used. In general, 5000 litters weighing more than 15 grams per 1â„5 hectare are stocked, and daily management and feeding practices follow the practice of intensive breeding. However, they are generally not graded and sparse, with an annual yield of about 1 ton.
3. Polyculture of fishponds in the ponds of farmed fish, 30 to 50 fishes per 1/5 hectare, stocking of small ponds and shrimps in ponds, and stocking of more than 15 grams at the beginning of the year. By the end of the year, it will grow to 200-400 grams and it will produce 10 kg. The ponds with better conditions can also be mixed in high density. Each week, about 5/100 hectares of earthworms are reared with about 500 fish. The feed for squid is fed once a day, which is 1% to 2% of the carp's weight. The carp also has to feed on the ponds. Fish, shrimp, etc., yield higher.
One, quail breeding technology, fresh meat, nutritious, delicious nourishing, was regarded as nourishing treasures, on the table. In recent years, the consumption of cesium in the world has increased year by year and prices have also risen. With the improvement of people’s living standards in our country, the consumption of cesium has also increased rapidly, and prices have also been increasing. It is worth developing vigorously to develop the raising of oysters, producing good yields, and increasing exports of goods.