Pufferfish rearing fish species 10-15 days before stocking, the net box should test the water. Requirements for fish species body surface integrity, no disease or injury, robust, neat specifications. Here are the methods of rearing puffer fish that I have carefully organized for you to take a look.
Methods of rearing puffer fishA breeding method and breeding environment
Breeding sea area requires clean water rich in dissolved oxygen, no red tide occurs, no pollutants and sewage inflow. It is better to choose a sheltered inner bay for net culture, with a transparency of 7-8m, a flow rate of 10cm/s, and an optimal water temperature of 16-23℃, which is unfavorable for its growth when the water temperature is lower than 9℃ or higher than 28℃.
At present, the Japanese puffer fish culture is mainly net box culture. In the first year, polyethylene nets are used from juvenile fish to 1-year-old fish. When the weight reaches more than 300g, it is moved into metal net box with 4cm mesh for feeding until it is listed for sale. Domestic net box culture puffer fish net box specifications for 3?3?5m, mostly found in the southern coast, most of the northern pond culture, the area of several thousand to tens of thousands of m2 ranging, pool depth 2-2.5m. In addition to mono-culture, in recent years, there are also mix-culture, Zhejiang, in 92-93 years in the Shenjiamen Oriental dolphin and shrimp mixed culture in the soil pool has been a success.
Second culture and growth
Fry weighing 3-4g, from June to July in the net box, to the end of December up to 400g or so, to the end of the second up to more than 1000g. At this time, they can be harvested and marketed. The best market size for red finned oriental dolphin is 1kg, which has the highest price. In order to achieve better breeding results, the fish weight should reach over 350g before wintering. Before December, the water temperature is still suitable for growth, so it is important to feed sufficient bait. During the overwintering period, when the fish can still feed, it is also necessary to ensure a small amount of feeding as much as possible, in order to prevent weight loss and ensure the stability of the survival rate. After overwintering, normal growth resumes from April. Especially in September-November when the water temperature is favorable, its growth is more rapid.
Specific management measures:
① before the release of seedlings to select consistent specifications, healthy and lively seedlings, and at the same time to understand the management of the seedling period and the presence of deformed seedlings.
② Seedlings must be bathed before stocking to prevent the invasion of parasites and other diseases.
③The transfer and transportation of fry should try to use large containers, so as to avoid injuries to the species of fish fry.
④ The best way to prevent predation is to produce and use healthy fry. Healthy fry show cluster activities in net boxes and breeding ponds, and it is not easy for scavenging to occur in such a state.
⑤ To be sorted twice in May-November, it is better to let the old and new nets connect together when changing nets, so that the fish can be transferred naturally to avoid abrasion of the fish body.
⑥ Chilled bait is best processed with ice to keep the bait as fresh as possible and prevent protein deterioration.
⑦ Fresh bait should be fed from early morning to improve the enthusiasm of the fry to feed on the bait.
Three bait types and feeding methods
The kiddies use mysis shrimp, prawns and mackerel, and the adults use sardines, mackerel, mackerel, and mackerel, as well as spot, six-lined fish, swordfish, and mackerel, etc.
The bait types and feeding methods are based on the same principles as the bait types. In order to improve the quality of the fish at harvest time, squid, shrimp, oysters and clams are also fed.
In order to avoid the phenomenon of mutual cannibalism, it is necessary to feed the appropriate bait and determine the number of times and amount of bait. The weight of the fish is less than 50g 4 times a day, 50-100g 3 times a day, more than 100g twice a day can be. When the water temperature drops below 15℃, the amount of food intake decreases, and below 10℃, the food intake stops completely. From December to March, when the water temperature is low, feeding once a day is enough. The general baiting amount of fish before 50g is 30% per day, 15% when 50-100g, and 10% when more than 100g, but it should be based on the satiety of the fish.
Pufferfish net box culture technologyNet box aquaculture pufferfish has the advantages of maneuverability, flexibility, simplicity, wide adaptation of waters, and simple operation.
Breeding waters:
Choose the wind and sunny, quiet environment, fresh water, no pollutants, no obstacles, wide water surface, good sunlight conditions for net box breeding waters. Waterways, dams, locks, main rivers and water flow rate of more than 0.1 meters per second are not suitable for the installation of net boxes. The bottom of the net box should be more than 0.5 meters away from the bottom of the water to prevent the net box from running aground. Set the net box in the waters of the general year-round water depth of 3-6 meters, dissolved oxygen in more than 4 mg per liter.
Net box setup:
When the specification of puffer fish is about 3 cm in body length, the mesh of net box is 6 meshes per square centimeter; when the specification of puffer fish is more than 8 cm in body length, the diameter of mesh is 1.5 cm. The size of the net box is 5 meters?8 meters?2.5 meters, and the upper mouth is 30 centimeters above the water surface. In the more open water, the net box arrangement should be zigzag, plum blossom or herringbone, the distance between the net box for 15-30 meters; if restricted by the water conditions, the net box must be arranged in a zigzag pattern, it should be every 2 nets into a group, the interval between each group is more than 50 meters. The area of the net box for feeding is generally about 4% of the surface of the water being set.
Fish stocking:
10-15 days before stocking, the net box should be tested. Requirements for fish species body surface integrity, no disease or injury, strong body quality, neat specifications. Before the puffer fish species into the net box, choose to put the oxygen bag with fish fry into the box to adapt to 15 minutes, such as the water temperature in the bag and the water temperature in the box is roughly the same as when the fish species released. Stock about 12 fish per square meter. In order to prevent a lot of moss growth in the net box, the net box should also be accompanied by a small number of plant-eating fish.
Bait feeding:
Baiting should be done at regular intervals, points, quality and quantity. The net box is stocked with appropriate amount of water plants such as peanuts, and the water plants cover about 20% of the water surface. One week before the dolphin is stocked, first splash soybean paste and sprinkle soybean residue in the net box to cultivate the early bait for the dolphin. After the puffer fish enter the box, start feeding the bait mixed with rolled fish pulp and wheat flour in the ratio of 3:1, and the feeding quantity is 10% of the fish weight. The bait is placed on the food table and fed twice, at 9:00 am and 4:00 pm.
Daily management:
Daily management mainly includes one hard, two grasp, three prevention. One hard that is hard to check. Before the net box in the water to check the net clothes have no damage, after the water to check whether the box is box-shaped, rinse the net box in a timely manner. Check whether the net box is intact in the morning, noon and night every day. Observe the fish and water conditions diligently. Two grasps: one grasps the timely washing box. Cleaning the net box usually wash the box machine to rinse the mesh on the adherents clean. Requirements for careful operation, so as not to wash the fish body. Do not wash the net box too hard. The second grasp the right time to move the box. Should be based on water conditions, water quality changes, move the box at the right time. In the net box position decline or flood eve, must be timely to move the net box to the water level suitable for the safety of the waters to go. Three defenses: one against fish disease. Before stocking fresh seeds, use 3%-5% concentration of salt water to soak for 10 minutes; choose disease-free bait and soak the bait in 3%-5% concentration of salt water for about 15 minutes before feeding or storage; splash lime water once a month. Regularly check the body of the fish, because it likes to swim around the box, easy to bruise the body. Generally every 10 days to fish up all the fish in 2% - 3% concentration of salt water immersion for 15 minutes, to prevent parasites and bacterial epizootics, and regular feeding furazolidone, sulfonamide drugs. Secondly, prevent gale and flood. Keep abreast of the weather conditions and move the nets before the gales and floods come. Third, prevent the loss of the net box. Specialized personnel should be assigned to guard the net box day and night to prevent loss. At the same time, it is also necessary to prevent rats, otters, waterfowl and other harm to the puffer fish.
Fish out of the net:
Fish species to reach the specifications of the box and the box or raised to the standard of commercial fish, it is necessary to timely out of the box. The method of taking fish out of the box is: the two working boats were rowed to both sides of the net box, the first two corners of the net box to lift the bottom of the net, and then use bamboo poles into the bottom of the net to block, slowly drive the fish to one end of the net box, and then the bamboo poles resting on the pontoon, pontoon corner resting on the bow of the boat with a rope tied to the mouth of the net box unlocked, and the fish with the fishing rod to reach into the box fish fish out. Put the fish species that meet the conditions for rearing into the fish species net box or adult fish net box, and put the small fish species left behind back into the original net box for rearing. If the number of small fish species left behind is not large, you can combine the small fish species in several nets into one net box.
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