CATDOLL : CATDOLL: Will mandarin fish grow less than crucian carp?

In the same water area, the reproduction rate of mandarin fish is always lower than that of crucian carp, so the total number of mandarin fish must be less than that of crucian carp.

Mandarin fish - breeding technology

mandarin fish

Atlas of Mandarin Fish Breeding

Parent fish selection and cultivation: Mandarin fish prefer flowing water to spawn. For artificial breeding, select healthy and disease-free parent fish weighing 1-2 kg for special ponds. When feeding wild fish or commercial feed, artificial induction of labor can be performed, and carp pituitary or HCG, LRH--A and other hormones can be injected, and the ovulation can be allowed to occur naturally. Mandarin fish eggs are slightly sticky and have a higher specific gravity than water, so they sink to the bottom of the water easily. When incubating in a loop, the flow rate should be increased, and should not be less than 0.2 meters per second. Fertilized eggs can hatch into fry after 3-4 days. More fry can be obtained by artificial insemination. Natural fry can also be caught for breeding.

Cement pools with an area of ​​several dozen square meters are suitable for seedling cultivation. The water quality should be fresh and there should be a micro-current. In addition, a small feed fry cultivation pool (other fish species whose breeding period is basically synchronized with that of mandarin fish) should be set up to ensure the supply of live feed. Mandarin fish have the habit of the strong preying on the weak. When there is a lack of feed, they will cannibalize each other, which affects the survival rate. If there is sufficient feed, the fry can be raised for 10 to 15 days and can be raised into summer flower fish of about 3 cm. At this time, it can be transferred to adult fish breeding.

Breeding method: Polyculture: one is polyculture in the adult fish pond, and the other is polyculture in the parent fish pond. Generally, around May, 3 cm mandarin fish are stocked. In the adult fish pond with more wild fish, 20 to 40 are stocked (the minimum size of the domestic fish should be 1 times larger than that of mandarin fish), and 30 to 50 are stocked per mu of fish pond; in the adult fish pond with more tilapia and crucian carp, more can be stocked, 50 to 70 per mu; in the pond with too many tilapia, about 100 per mu are stocked. Ponds where mandarin fish are mixed should not be stocked with summer flowers such as silver carp and bighead carp, because mandarin fish grow fast and will swallow small-sized domestic fish species. Since mandarin fish consume more oxygen than domestic fish, the water quality of the pond where mandarin fish are mixed should not be too fertile, and new water should be injected at a regular time. Mandarin fish are sensitive to drugs. When applying drugs, the concentration should be calculated accurately. Use low doses or stop using drugs in seasons with high water temperatures. Mandarin fish are raised in fish ponds, mainly using natural wild fish in the pond as feed, and some tilapia broodstock can also be raised to breed fry for food. Ponds near rivers and lakes with conditions can be filled with river fry and wild fish can be introduced as food. Mandarin fish can grow to commercial size of about 300 grams after 4 to 5 months of breeding, and 5 to 8 kilograms of mandarin fish can be produced per mu.

Single breeding means breeding in a dedicated pond. The pond area is about 1 mu, the water depth is 1.5 to 2 meters, the water quality should be fresh, and the water should be kept at a low flow. About 1,000 summer flower mandarin fish of about 3 cm are placed per mu, and tilapia, wheatear fish, shrimp and other wild fish, or minced snails and clams are reasonably added according to the fish stock for mandarin fish to eat. The feeding amount is 3% to 5% of the total weight of the mandarin fish in the pond.

Farming technology

To obtain high yield benefits for pond carp breeding, breeding technology is the key, and attention should be paid to the following aspects:

1. Technology of pond culture for adult crucian carp:

Crucian carp is cultured in ponds, mainly using four farming methods: mixed culture in adult fish ponds, culture in fingerling ponds, culture in broodstock ponds and culture in main ponds.

1. In the fish pond, crucian carp is mixed with silver carp, grass carp, bighead carp, bream, bream, carp and other species. Large-sized fish should be stocked.

Crucian carp

Crucian carp (20 photos)

The stocking time should be early rather than late, that is, stocking in winter is better than stocking in spring. The stocking density is 150 to 250 per mu of water surface. The stocking specifications and quantities of other fish are determined according to needs. The requirements for crucian carp breeding ponds are not high, generally 0.1 to 2 hectares in area, and a pond with a water depth of more than 1.5 meters is sufficient. It is best to have 10 to 15 cm thick silt at the bottom of the pond. The cleaning, disinfection, and basal fertilizer application of the pond are all carried out according to conventional methods, and the survival rate can reach about 80%. After about 200 days of feeding, the majority of individuals weigh more than 200 grams, and the output per mu of water surface reaches more than 20 kilograms.

2. The area required for raising crucian carp in the pond is 0.1-0.2 hectares, the water depth is more than 1.5 meters, and there is 10-15 cm of silt on the bottom of the pond. The pond with domestic sewage in front of and behind the village is better for raising crucian carp. Use quicklime to clean and disinfect the pond one week before stocking the fish, and add water 2-3 days after disinfection. When filling the water, use a mesh to filter at the water inlet to prevent wild fish from entering the pond. For each acre of water surface, 1,500 5.0-6.5 cm crucian carp for wintering or 2,000 large-sized fry hatched in the same year are mainly released, and about 40% (600-800) grass carp, silver carp and bighead carp for wintering are added. The stocking time should be early rather than late. Feed concentrated feed as the main feed on a daily basis, supplemented by fertilization to cultivate water quality. The annual feeding amount of concentrated feed is equivalent to about 2.5 times the expected output of Pengze crucian carp. The system uses fixed-point feeding, and the daily feeding amount is determined according to the growth of the fish, weather, water temperature and the feeding intensity of the fish. Fertilizers or new water are added in time according to the water quality. Under normal management, 200 kg of crucian carp with an average weight of about 150 grams per tail can be obtained in the same year, and about 200 catties of grass carp, silver carp and bighead carp can be obtained. Due to the high proportion of high-quality fish, its net profit is also higher than other breeding models.

3. Cultivate crucian carp in fish fry ponds. Cultivate fish in fish fry ponds for silver carp, grass carp, bighead carp, bream and bream, but not in carp and tilapia fingerling ponds. The required area of ​​the pond for cultivation is 0.1-0.2 hectares, and the water depth is 1.0-1.5 meters. The cleaning, disinfection and basal fertilizer application of the pond are the same as the conventional methods. Cultivate crucian carp in other fish fry ponds, and only the fish hatched in the same year can be released. The stocking time should be early rather than late. Generally, when the fish hatched in the main breeding year are transferred to the overwintering fish breeding ponds, the fish hatched in the same year should be immediately released for breeding; the stocking specifications should be large rather than small, and the stocking density is 150-220 per 0.07 hectares of water surface. The stocking quantity, specifications and proportion of other fish hatched in the same year depend on production needs and pond specifications. Crucian carp fry are bottom fish, so they generally do not affect the living space of domestic fish species, and can make full use of water space. Therefore, the fish hatched in the same year are raised in the fish fry pond, which basically does not affect the stocking density and pond specifications of the main fish species; and because crucian carp mainly feed on residual bait and pond bottom plants and animals in the domestic fish fry pond, there is basically no need to increase the investment of funds and feed. Under normal feeding and management conditions, crucian carp fry are raised in the fish fry pond. After 150 to 180 days of feeding, the annual water size can reach more than 200 grams, and the yield of adult crucian carp can increase by 25 to 40 kilograms per 0.07 hectares of water surface.

4. Raising crucian carp in broodstock breeding ponds. In southern my country, artificial breeding of domestic fish is usually completed in mid-May to late May. The gonads of broodstock are in the recovery period after birth. In order to restore the physical strength of broodstock as soon as possible and promote gonad development, ponds are mostly intensively managed. In addition to arranging broodstock breeding and matching other fish, this kind of fish pond can also be stocked with 200 crucian carps of 5 to 6 cm per 0.07 hectares of water surface. Crucian carp are raised in broodstock breeding ponds, and the stocking time is generally carried out at the same time as broodstock. The breeding (cultivation) method is carried out according to the conventional method of broodstock of main domestic fish. The breeding of broodstock must follow the law of their gonad development. Generally, crucian carp raised in broodstock breeding ponds cannot be caught at the end of the year. They must wait until the next year when the broodstock undergoes pre-birth intensive breeding before they can be completely caught. After 250 to 300 days of breeding, 25 to 45 kg of crucian carp can be obtained per 0.07 hectares of water surface, with an average individual weight of more than 200 grams.

2. Farming crucian carp in rice fields

Crucian carp can be cultured in paddy fields with fertile soil, convenient irrigation and good water and fertilizer retention performance. Generally, double-season rice is cultured continuously. Single-season rice is difficult to reach adult fish specifications due to its short time. Before releasing fish, the field ridges, fish ponds (fish pits) and fish ditches should be excavated and repaired in the field according to the size of the rice field, water source and water inlet and outlet. The field ridges should be solid and watertight; the area of ​​the fish pond varies from place to place, ranging from 3 to 5 square meters per 0.07 hectares of water surface, and 20 to 30 square meters in some places. Generally, the area of ​​the fish pond is about 5%, and the water depth is about 0.8 meters. The number of fish ditches depends on the shape and size of the field surface, and there are many forms such as "one" shape, "ten" shape, "ten" shape, "thirty" shape and "mouth" shape. Crucian carp can be cultured alone or in a mixed manner in rice fields. The stocking specification is 5.0 to 6.5 cm fry. Fish can be stocked one week after early rice is transplanted, with 250 to 500 fry per 0.07 hectare of water surface. Without feeding, more than 20 kg of crucian carp with an average tail weight of about 100 grams can be harvested in autumn. If some concentrated feed is added, the crucian carp yield in 0.07 hectare can exceed 35 kg. Daily management is the same as that of other fish farming in rice fields. It is recommended to apply more organic fertilizers to make the rice fields richer in organic matter to facilitate the growth of crucian carp. At the same time, anti-escape equipment should be well prepared to prevent them from escaping against the water.

(III) Farming crucian carp in small reservoirs and lakes

Small lakes and reservoirs with abundant natural bait and fertile water are suitable for stocking crucian carp. Intensive or semi-intensive breeding of lakes and reservoirs with feeding and fertilization is more effective. Stocking crucian carp in lakes and reservoirs that have been dried up or dried up for fishing within 1 to 3 years can generally achieve a good effect of increasing production and income. Since the water surface of lakes and reservoirs is relatively large and there are many enemy fish, in order to improve the survival rate of crucian carp, large-sized fish species should be stocked as much as possible, with a stocking density of 20 to 50 per 0.07 hectares of water surface. Stocking time can be winter or spring. High-yield lakes and reservoirs that release water for fishing every year can increase the number of crucian carp stocked, and can be managed in accordance with the pond farming crucian carp technology. In lakes with abundant natural bait and fertile water, the growth rate of crucian carp even exceeds its growth rate in ponds, and the individual weight reaches more than 250 grams in the same year. In lakes and reservoirs that have been dried up or dried up for 2 to 3 years, a considerable proportion of crucian carp weigh more than 500 grams.

(IV) Cage culture of crucian carp

Using large water surfaces such as reservoirs and lakes for intensive cage production without occupying land area and pond surface is an attempt at a new breeding method. Due to the large surface area of ​​large water bodies such as reservoirs and lakes, the water inside and outside the cage can be fully exchanged, so the dissolved oxygen is sufficient; secondly, the activity of fish cultured in cages is small and the energy consumption is low, which is beneficial to the growth of crucian carp. The specifications of the cages generally require an area of ​​16 to 28 square meters and a height of 2 to 3 meters. The mesh size is determined according to the specifications of the stocked fish species. As long as the fish does not escape, a large mesh should be used as much as possible to increase the exchange of water inside and outside the cage. It is better to use 3×3 polyethylene mesh wire as the cage material. The cage setting methods usually adopt floating and fixed methods, with a cage spacing of 2 to 3 meters and a row spacing of about 20 meters. The following factors should be considered to determine the location of the cage:

Choose an area with slow current, stable water level, sheltered from the wind and facing the sun, with a flat bottom. The bottom of the water should preferably be gravel and the water depth should be 5 to 6 meters.

The surrounding environment must be rich in vegetation, fertile water, and abundant in food organisms.

Waters with industrial pollution cannot be used as locations for setting up cages.

Cage-cultured crucian carp is generally raised alone, and can also be matched with a certain proportion of silver carp, bighead carp, and black carp, which is generally controlled within 3% to 5% of the total output. 50 to 200 crucian carp seedlings with a size of more than 5 cm are stocked per square meter, and the fish species in the same cage must be stocked at one time. The stocking specifications must be neat, otherwise the size of the fish will become more and more disparate. Cage-cultured crucian carp must be fed. It is better to feed artificial compound feed, semi-floating or sinking granular feed. The bait formula can refer to the formula for carp cage farming, and the protein content can be slightly lower than that of carp bait. Feeding a small amount of bait multiple times is the feeding principle of cage fish farming. The amount of bait each time is determined based on the standard that 90% of the bait is eaten before leaking out of the cage, and the last little bait is rarely competed for by fish. Feed 4 to 6 times a day, and no feeding at night. Other daily management is the same as conventional cage fish farming. After 180 to 200 days of breeding, the average weight of the fish can reach more than 200 grams, and the yield per square meter can reach 8 to 25 kilograms.

Identification of fish species

When purchasing crucian carp fingerlings, farmers should correctly distinguish the counterfeit and inferior fish fingerlings based on the biological characteristics of the main crucian carp breeding varieties to avoid being deceived and suffering losses.

Choose the main species

The main crucian carps are silver crucian carp, Pengze crucian carp and Xiangyun crucian carp. Among them, Xiangyun crucian carp has the fastest growth rate, followed by silver crucian carp and finally Pengze crucian carp. However, Pengze crucian carp is better than other varieties in appearance, and Pengze crucian carp is still the main export commodity.

Fingerling stocking density design

In order to reduce breeding costs, it is best to breed large-sized fish yourself.

Using ponds to cultivate crucian carp fingerlings, stocking 8,000 to 12,000 summer crucian carps per acre can achieve the goal of growing to a size of 50 to 60 grams.

When raising adult crucian carp, when the average size of the fish is 50-60 grams, it is ideal to stock 1500-1800 crucian carp per acre, and the size of the cultivated commercial fish can reach 350-400 grams.

Variety Match

When breeding large-sized crucian carp, do not mix grass carp and crucian carp, but choose silver carp and bighead carp. The number should account for about 20% of the main crucian carp, and bighead carp should account for about 10% of the silver carp. The stocking time of the matching species should not be too early, especially the early introduction of bighead carp will have a greater impact on the domestication of crucian carp.

Fish domestication

It is relatively easy to domesticate fish in the breeding stage. The domesticated fish have a shorter time to surface and grab food when they are raised as adult fish, making them easier to manage.

Adding appropriate amounts of additives to the feed during domestication can shorten the domestication time and increase the feeding area and quantity of crucian carp.

The influence of density on domestication. The higher the density, the larger the population and the easier it is to domesticate. When the density has been determined and cannot be changed, the water level in the pond can be lowered to increase the density relatively, which is conducive to domestication and can also increase the water temperature in the pond and promote fish growth.

Silver carp and bighead carp should be released after the main cultured crucian carp develops the habit of floating up to grab food.

The water quality during the acclimation period should be "clear and thin" rather than "turbid and rich".

Managers need to be patient and serious during domestication.

Feed particle size and feeding rate

The selection standard of crucian carp feed particle size is "small rather than large". Generally, when the crucian carp size is less than 10 grams per tail, the feed particle size is 0.5mm; when it is 10-30 grams per tail, it is 1.5mm; when it is 75-100 grams per tail, it is 2.0mm; when it is 150-300 grams per tail, it is 2.4mm; when it is more than 300 grams per tail, it is 3.2mm.

The feeding capacity of fish is directly affected by the size of the fish and the water temperature of the pond, so the feeding rate should be adjusted randomly according to the actual situation and should not remain unchanged.