Long-distance Transport and Domestication and Domestication of Red Fin Oriental

In recent years, marine aquaculture of Takifugu Rubripes has been carried out in coastal provinces and cities and has become a new species of mariculture in China. At present, most of the seedlings required by the breeding units must be transported over long distances, and due to the high price of rice seedlings, which accounts for a large proportion of the total cost. During the transportation period, the water temperature is as high as 25°C to 30°C. The long-distance transportation and domestication become a crucial link in river farming. The transportation of the seedlings and the domestication of the domesticated fishes determine the success or failure of the Red Fins Oriental breeding.
First, facilities and methods
1. Transport facilities. The transported seedlings were made of 120 pressurized wood-structured live water transport ships equipped with a water pump driven by 12 diesel engines with a flow rate of 20 tons per hour.
2. Cage facilities. Aquaculture cages are set up in Luhai District, which is named by Nanzhao State. The specifications of cages are 3.0mx3.0mx2.5m and meshes are 0.4cm.
3. experiment method. The fry originated from artificial seedlings at the nursery, with a total of 3,840 tails. The selection of fry requires the selection of seedlings with low mortality during the nursery period, normal swimming of the fish in the nursery pond, low deformity rate, and strong water repellency. Before the fry is transported, the potassium permanganate is used to disinfect the living water boat and the in-cab equipment. During transport, a small amount of yeast is fed to the fry, and a 25W lamp is lighted at the hatch at night. When raising fish for domestication, the fish should be examined one by one before entering the cage, and fish fry or other fish with obvious mechanical damage removed from the fish should be removed. The stocking density is 916/net cages. The fresh shrimps are used for bait and they are fed daily. More than 4 times, a 40W lamp was lighted at the top of the cage at night, and 2ppm potassium permanganate was used for disinfection at the time of the tide, and the bait containing 2g of berberine per kilogram of bait was fed.
4. Natural conditions at the time of transportation. On July 13, the weather was cloudy and rainy. On the 14th, it was sunny, and gusts were ranked 5-6. The temperature of the gurgling water was 22.0°C, and the water temperature in the south was 26.1°C. The transportation time was 31 hours.
Second, the results
1. Long-distance transportation results. The live water vessel departed at 7:00 on July 13 and arrived at Nanxun at 14:10 on July 14. It sailed for approximately 268 nautical miles. The transport time was 31 hours. The density of fry was 1600/m3, and the survival rate was 95. 5%.
2. Temporary domestication. Due to the long-distance transportation of fish, the body is relatively weak and comes out of the nursery pond. It needs an adaptation process to the outside world, so it is necessary to carry out the domestication of the fry. After the boat arrives at the fish raft, the net cage in the cabin shall be stowed and the seedlings in the bucket shall be transported to the holding cage. The operating time shall be shortened as much as possible. Before the fish fry enters the cages, the tailless shank and the bitten seed should be removed. At the time of the flat tide, the net should be pulled and the fish should be disinfected with 2ppm potassium permanganate 0.5m away from the water surface to prevent infection. The minced shrimps were fed within one week to restore their physique as soon as possible, and 2 g of berberine was added to each kg of bait to make baits to prevent enteritis after long-distance transportation.
Third, discuss
1. Artificial breeding, seed selection is the key. The first batch of seedlings in the nursery site should be selected as much as possible. The first seedlings are of good quality, fast growth, and neat seed size. They have low mortality, strong activity, regular swimming, and water resistance in the water during artificial breeding. Strong, such seedlings can guarantee the survival rate of transportation and domestication.
2. Make preparations before transporting. A transportation plan shall be formulated to arrange transportation means according to the number of transported seedlings, road conditions, and the weather conditions of the sea. The date of transportation shall be determined, and the transportation of the vessel shall be well connected with the tidal waves of the ports of both sides during loading and unloading. In addition, quarantine certificates, purchase-miao invoices, and shipment-licensing licenses and ship certificates must also be prepared in preparation for inspection during transit. According to the size of the living tank, a net cage was made of 10 mesh-20 mesh double-wire polyethylene no-nodular nets, and the cage was fixed in the cabin so that the nets could be taken for fish raising.
3. Several issues that need to be paid attention to in long-distance transportation of fry: Fry loading and transportation should be conducted in a weather-free manner to facilitate the reduction of fry damage during operation. The fry should be stopped for 3 hours before loading. The pump is started 1 hour in advance to ensure that the water in the fresh water tank is fresh when installed. Do not directly face the seedlings of the water pump. The outlet of the water inlet pipe should be equipped with a porous water outlet device to prevent the water in the living water tank from flowing too fast and consume the fish. The front of the drainage pipe is equipped with a barrage device to prevent the fry from being sucked and cause the fry to stick to the net and die. Under the premise of ensuring the survival rate of fry transportation, in order to reduce the cost of fry transportation, the density of the transport fry can be properly increased. According to the effective water body of the living water tank, the general transport length is 2.5cm--3.5cm seedlings 3000/cubic. m - 4000/m3. Live water ships must stock enough bait to be used during navigation. The food can be shrimp, yeast, etc. During the voyage, it is necessary to pay attention to the strong wind forecast and if necessary, enter the harbor to shelter from the wind.
4. Seedlings are best transported from the Qingshui District. When the mixed water area passed, we found that the seedlings were slowed down and the seedlings were scattered.
5. After the arrival of the fish fry, care should be taken when moving the fish cages from the cabin to the cages. Care must be taken to prevent fish fry from floating on the cages when the nets are raised in the cages, causing the fry to suck water and air into the stomach and raise the belly. When the shark's constitution is weak, it can easily lead to death.
6. To achieve good results of domestication and conservation, in addition to an ideal holding environment and prevention of disease, it is necessary to strengthen feeding and management. After just being transported, the fish fry slowly enters the cage, the swimming is not standardized, the response to external stimuli is not sensitive, the food intake is slow and the food intake is small. Fresh shrimps should be selected, appropriate amount of vitamins and antibacterial drugs should be added, and feeding should be increased. Times, extend the feeding time, small meals, wait 2 days - 3 days later, fry show behavior of feeding, feeding can be fed regularly every day 4 times - 6 times.