California's cowardly meat is aggravated by severe food and fratricide, and the growth process is prone to individual size differentiation. Therefore, the fry cultivation stage should be strengthened in management to avoid the occurrence of weak meat and strong food, and to avoid economic losses.
California salmon seedling cultivation is generally divided into fry cultivation stage and fingerling cultivation stage. The common methods of fry cultivation stage include earthen pond cultivation and cement pool cultivation.
Earthen pond cultivation
Pond conditions: It is better to cultivate ponds with California seedlings in order to use earthen ponds, which are rectangular, east-west, and sunny. Adequate water, good water quality, free from pollution, the area is ideal for 1 mu to 3 acres. The pond has an independent water inlet and drainage system. The pool is 2 meters high and the water depth is 1 meter to 1.5 meters. The silt in the bottom of the pond is controlled within 10 centimeters.
Pond preparation: Drain the pond water in winter, remove excessive silt at the bottom of the pond, expose to sunlight, remedy the pool and enter the drainage facilities. The following year, when the water temperature is stable above 15°C, the new water should be filled to 1m deep. The mu should be disinfected with quicklime water. After 7 days, the water quality of the soybean milk should be used, and the quality of the water should be adjusted to the best state by microbial preparation.
Tap water stocking time: about 10 days before the bottom of the fish pond with lime or tea pot clear pond, disinfection of the pond into the water 50 cm to 70 cm, appropriate fertilization, fertility water quality, increase plankton biomass, transparency maintained at 25 cm ~ 30 In centimeters, it is better to use mung bean green. About 15 days to 20 days after the ponds were sterilized and cultured, the food organisms in the pond, such as small horned horns and copepods, reached a peak, and the nitrites, ammonia nitrogen, and pH values ​​of the ponds were promptly dropped into the California catfish splashes. The water temperature is strictly controlled above 15°C, preferably above 18°C, so as to ensure that the fry is not frozen by cold waves.
Stocking Density: Acre stocking The quarantine-qualified squid density is about 150,000 to 300,000 depending on the fatness of the fish pond. The temperature difference during stocking should be controlled within 2°C to avoid the death of the fry in the pond.
Feeding and management Baits Biology culture: After the fish is in the pond, it feeds plankton in the water. Therefore, it is necessary to maintain a certain amount of planktonic water and provide enough plankton. If the amount of plankton is low and the food is not enough, the fish will swim along the pond. Go, you need to take plankton to feed. When the body length of the fry was 1.5 cm to 2 cm, it began to enter the domestication stage, causing it to feed on fish flesh, and gradually transitioned to compound feed. To ensure the supply of bait fish fry creatures. The fish seedlings will be sprayed with 2 kg to 3 kg of soybean milk every 3 days after the lower pond, and try to maintain the number and time of the food organisms.
Frying domestication: The California baboons' open bait is a plankton which is cultivated with fertilizers. It is generally needed to be fed for about 15 days. Please pay attention to the following points during fry cultivation:
Cultivation of water spiders prior to release: As long as water spiders are sufficient, the survival rate of nursery will be much higher. Generally use "EM compound bacteria + peanut bran" in the barrel to ferment for one week and then put it into the pond. "Generally, a pond (6 mu to 7 mu), 10 jin of EM compound bacteria and 100 kg of peanut bran, the water spider is enough to put the seedlings in. The fry grows to 6 to 7 to start using the fish paste + water spiders for a week. After the fish slurry is simply fed, the feed can be started after 7.5 and the feed is initially fed at a ratio of 10% feed + 90% slurry, and then the proportion of feed is gradually increased, and after about half a month, it can be converted into feed. Before the feeding, the water was dialed to attract the small fish to feed, and it was allowed to form conditioned reflexes. The daily domestication time required 6 hours to 8 hours. Since California salmon is a carnivorous fish, once it grows in different sizes, it appears serious. Mutual killing, especially high-density pond nursery stage, before 6 cm, killing each other the most serious, should be based on the growth of fry (usually 15 to 20 days of cultivation) with a fish sieve for grading, separate feeding, will help to improve The survival rate of fry.
Water quality regulation: New water is added at the right time to expand the water space. Microorganism preparations are applied every 5 days to regulate water quality. Open the aerator for 2 hours to 4 hours at noon on sunny days to avoid fry death from fish fry.
Grading: The fry is cultivated from 15 days to 20 days, and the body length has reached 2 cm to 3 cm. At this time, the fry should be reared in time. Prepare graded ponds approximately 10 days in advance and cultivate sufficient food organisms. About 50,000 small-scale fish species of about 3 centimeters will be placed on the mu, and 4 cm to 5 centimeters will be grown on the second level. This process takes about 10 days to 15 days. This stage can periodically quantify and feed sterilized blisters, supplemented by light, water, and other foods.
Other management during the seedling stage: Injecting water into ponds in stages during the feeding of California salmon fry is an effective measure to increase the growth rate and survival rate of fry. Usually every 5 days to 7 days water injection, each time about 10 centimeters of water injection, until the ideal level, and later according to the weather and water quality, appropriate replacement of some pool water. When water is injected into the water inlet, dense nets are used to filter the wild fish and pests, and at the same time, the flow of water is to be flushed directly into the pool bottom to stir the pool water.
When there is a shortage of feed, California is susceptible to large fish and small fish. Therefore, the following points must be made: (1) Fish fry in ponds should be hatched in the same batch to ensure that the fry is relatively tidy. 2 In the process of seedling cultivation, the net should be screened and grading in a timely manner. Especially in the southern region, the seedling density is high, and the number of times required for screening is also many. 3 Timely, quantitative feeding, ensure that enough feed is provided to ensure that all fry can feed, so that the individual fry grows evenly, reduce self-killing and increase survival rate.
Insist on patrolling the pond at dawn, noon and evening to observe pool fish activity and changes in water quality and water quality, and to find out if problems arise and take timely measures. After the seedlings pay attention to weather and stress. During the fry stage, the body has weak resistance and is sensitive to changes in the external environment.
Cement pond nursery
The size of the concrete pool is 20 to 30 square meters, and the pool wall is smooth. Before washing, the tanks should be cleaned and checked for leaks. If leaks are found, repair them in time. The depth of water is 20 cm to 25 cm. Afterwards, a small amount of fresh water is added every day, gradually increasing to 50 cm to 70 cm. Cumulatively hatched larvae range from 3000 to 5000 fish per cubic metre of water. From the second day to the third day after the hatching of the fry, the "open" bait was started. Initially, small zooplankton should be fed, such as rotifers and copepod nauplii, and fed twice or three times a day. The amount of feeding will increase or decrease depending on the feeding conditions of juvenile fish. When the fry grows to 1.5 cm to 2.0 cm, it is best to be transferred to a pond for cultivation. The cultivation density should be appropriately reduced and large zooplankton such as Cladocera, Copepoda, and Hydra should be fed. When the food intake is increased to 2 cm or more, fish slurry can be started and gradually fed into small pieces of fish.
Fish breeding: Pond area 5 mu ~ 10 acres, water depth ≥ 1.5 meters, pond sludge ≤ 10 centimeters; every 3 acres with a 3kw aerator; clear pond.
Fish stocking: After the pond water quality is up to standard, acre stocking 5 cm to 6 cm size fry 3000 to 4000 tails, mixed breeds large and medium size bream, carp species, control of water quality, with more than 3 inches of 500 white locust, calyx 100 tails.
Feed and Feed: Feed the whole price of crude protein ≥ 40% and crude fat ≥ 8% with sink or buoyant feed. Daily feed 3 times to 4 times, until the end of the year it can grow to an average tail weight of about 200 grams.
After the fry grows to a size of 3 cm to 4 cm in summer flowers, it can start to enter the breeding stage. The suitable area of ​​the pond is 2 mu to 5 mu, and the water depth is 1m to 1.5m. The drainage and irrigation are convenient and the dissolved oxygen is sufficient. After the disinfection of clear ponds, the water surface per mu is about 3 centimeters and about 30,000 to 40,000 fish species. When the fry grows to 5 centimeters, the appropriate stocking density is 12,000, and about 10 centimeters of fingerlings are suitable for stocking density. 5000 to 6000 tails, so while grading and grading at the same time, according to different specifications to sparse breeding density.
Practice has also proved that the adoption of sub-standard screening and sparse breeding density cultivation method is an important measure to improve the survival rate of California salmon species. Guangdong Province mainly feeds chilled fish slurry, which is fed 2 to 3 times a day, and the feeding rate is 4% to 6%. California's cockroaches are relatively timid and they don't come into contact with food. They are probably somewhere between 20 cm and 30 cm underwater. However, they do not eat food that fell to the bottom of the pond. In order to make the species more uniform, the scientific feeding method is also particularly critical. On the one hand, it is best to feed in several places in the pond so that the feed is fully fed. The other aspect should try to extend the feeding time. , can make each fish can eat food, and be able to eat; or feeding too fast, chilled fish sinking bottom will not be California quail feeding, not only waste feed, but also corrupt the water quality. After 50 days of cultivation, the size of the fingerlings can reach 1.0 cm or more, and they are then fed into adult fish ponds.
It is used for general isolation in outpatient clinics, wards, and laboratories of medical institutions; it plays a protective role during inspection and treatment in medical institutions, and blocks body fluids, blood splashes or splashes of national essential medicines For general isolation in the room, etc.; medical institutions play a protective role during inspection and treatment, blocking bodily fluids, blood splashes or splashes. The main components are usually composed of protective cover, foam strips and fixtures made of polymer materials. Mechanism of action [Material] overall food-grade flexible PVC silicone material; rigid polycarbonate PC explosion-proof lens
[Product Features]Surface wide field of view ≥270°; 8 concealed air vents; adjustable elastic fixing straps; light transmittance ≥90%; myopia glasses can be worn inside; anti-fog layer; eye-face fit, closed good sex
[Scope of application] It is used for general isolation in outpatient clinics, wards, and testing rooms of medical institutions; it plays a protective role during inspection and treatment in medical institutions, blocking body fluids, blood splashes or splashes. How to use This product is for one-time use. After use, it should be destroyed in the sales package.
Medical Goggles,Medical Isolation Goggles,Medical Eye Goggles,Medical Grade Goggles
Jilin Sinoscience Technology Co. LTD , https://www.jilinsinoscience.com