Indoor water quality requirements Seedling room water quality conditions meet the national standards of the People's Republic of China

"Fisheries Water Quality Standard" (GB11607--89) and the People's Republic of China Agricultural Industry Standard

Qualifications of "Quality-Free Food Aquatic Water Quality" (NY5052-2001). Education

The seedling water is treated by precipitation, sand filtration, and ultraviolet disinfection.

Broodstock and production

(1) Harvesting and holding of broodstocks

In the case of some artificially cultivated broodstock, the production of oriental seedlings still depends on spawning.

During the period, the broodstock will be harvested directly from the spawning ground. Fishing tools are mainly set nets and fishing

The captured broodstock was immediately moved into the indoor cement pool for raising, and the hormone oxytocin was injected after 24 hours.

. If the gonads have matured gonads, gently press the abdomen to squeeze out mature eggs and semen.

On-site collection of sperm and eggs for artificial insemination, fertilized eggs transported back into the nursery with oxygen bags

field.

(2) Selection criteria for broodstock broodstock should be selected for individuals with no damage to body and robust physique

. Which large species (such as Redfin Oriental?) requires a full length of 40-55 cm, weight 1.5-4 thousand

g; weight of medium-sized females is 0.75 kg or more and weight of males is 0.5 kg or more. Female fish

The abdomen is swollen, the genital hole is reddish, and slightly protruding outwards. The male has a light pressure

Semen flow out is appropriate.

(3) Artificially elicited broodstock in the sea area, usually after 1-2 injections of oxytocin

, spawning naturally in the spawning pool. Hormone dosage forms and doses: Used alone, per thousand

Cod fish weight injection of chorionic gonadotropin (HCG) 2000-3000 IU or yellow

Voxel Releasing Hormone Analogs (LRH-A2) 3-10 μg; Mixed use, per kilogram of fish

Reinject HCG500-1500 International Unit plus LRH-A22-3 micrograms. Spawning ponds and broodstock management

: Spawning pond area is suitable for 15-25 m2, water depth 1.0-1.5 m; broodstock stocking density 1-2

Kg/m. Male to female ratio is 1:1-2. Depending on the feeding condition of the broodstock, appropriate amount of bait, daily water change

Smudge once.

Incubation of fertilized eggs

(1) Identification of fertilized eggs Oriental eggs are multi-oil balls with heavy eggs and large eggs.

(Oval diameter is generally greater than 1.0 mm), pale yellow or pearl white, thick egg membrane, opaque

. The newly fertilized eggs are soft and harden after hours. Usually 1-2 days later, unfertilized eggs or necrosis

The egg gradually turns yellow, the surface is rough and crushed, and the fertilized egg is milky or

Light yellow, smooth egg membrane.

(2) Sterilization of fertilized eggs Eastern hatching time is long, dead eggs are easy to breed water

Fungi and other pathogens, so the fertilized eggs need to be soaked in a chlorine dioxide solution with a concentration of 2 ml/m3.

disinfection.

(3) Incubation method Glass fiber barrels with a volume of 0.3 to 0.5 m3 are used for incubation.

The part is funnel-shaped and is continuously inflated and flushed with water, and 0-1300 thousand eggs are placed in each barrel; or 60 mesh or

A 60-cm-diameter, 60-cm-high conical cage made of a 80-mesh sieve suspended in water

In the mud pool, continuous aeration and micro-flowing water were maintained, and 100,000 eggs were placed in each cage.

The indoor cement pool seed cultivation seedling cultivation can be divided into the previous period (about 10-15 days, self-incubation

Out to the full length of 4-6 mm) and later (full length 5-30 mm) 2 phases.

(1) It is advisable to cultivate a small cement tank with a volume of 10-20 m3 in the previous cultivation pond. kid

Fish have weaker light requirements and are usually controlled at 500-1000 lux. The seedling density is

1.5-3 million/m3. Hydrostatic, micro-aeration, and regular addition of chlorella to the body of water

The concentration reaches 100,000 cells/ml. After the larvae are open, they are fed with fortified rotifers and the density is

10-20/ml. Changing the water 2-3 times a day, change the amount of water to 1/3-1/2 of the total body of water, suck every day

Dirt 1 time. After 10-15 days of cultivation, the larvae have a total length of 4-6 mm. At this time, the teeth have grown.

There is also a difference in body size, and the phenomenon of mutual food is beginning to appear.

support.

(2) The rear incubation pond is an indoor or outdoor cement pool with a volume of 20-60 m3.

It can also be an outdoor pool (see soil pond nursery for details). Late larvae are slightly more adaptable to light

Lighting can be controlled at 1-3 million lux. The density of seedlings should be 1500-2500 tails/m3.

The rotifers were continuously fed and Artemia nauplii and copepods were added. The feeding density was 0.31.

Per ml, the amount of feed increases with the growth of the fish; when the juvenile is more than 1.0 cm in length,

All feed Artemia and copepods, the bait density is 1 / ml, and began to cast fish meat.

, feeding 2 times on the initial day, gradually increasing to 5-6 times a day; when the total length of the fry is 1.5cm

, instead of feeding all the fish. Changing water twice a day, change the amount of water 50%-100%; feeding fish

After the meat is cooked, increase the amount of water to be changed or adopt the flowing water method, and change the amount of water daily by 200% to 400%. Late period

During cultivation, depending on the survival and size of the fish fry, another sorting and easing can be conducted.

To ensure the healthy and rapid growth of fry. When the total length is 2.5-3.0 cm, it will reach commercial fish

Specifications.

Outdoor soil pond ecological seedlings, red fin Eastern, double-spotted Oriental, chrysanthemum yellow Oriental

The earthen pond nursery techniques such as the Obsidian Oriental have been successful.

(1) Nursery earthen ponds and nursery physicochemical conditions Nursery earthen ponds area 0.33-0.67 hectares

It is appropriate to have a water depth of 1.8 meters or more, sand and mud bottoms, and easy access and drainage. It is best to have fresh water

. Water temperature above 16°C, salinity 20-32.

(2) Clearing the pool and fertilizer before the water is released, dry the pool and expose the water to 20-30 centimeters.

, with water disinfection and wilderness, after the drug effect, filtering the water through the screen mesh 0.6-1.0 meters, fertilization

Keep water.

(3) larvae pond size and stocking density 2-3 days old larvae (before and after larval opening)

) Water can be transferred directly to nursery earthen ponds, or after cultivating for 5-10 days in an indoor cement tank

Remove outside. The stocking density is preferably 7.5-1.2 million/ha.

The seedlings of the Oriental seedlings that are cultivated out of the pond should be subjected to strict inspections and inspections before they are discharged from the pond.

Diseases, diseased seedlings, malformed seedlings, bacterin-resistant seedlings and other unhealthy seedlings should all be removed and destroyed on the spot.
(4) Physicochemical conditions for hatching Oriental? Fertilized egg hatching generally does not require light

High, just 500-1000 lux. The suitable hatching salinity of Haihe River is 22-3‰5.

The optimum hatching salinity is 28-32‰. The suitable hatching temperature is different depending on the species

Different, red fin Oriental, artificial eye is 14-22 °C, most suitable for 16-20 °C;

The square, double-spot east is 17-25°C, and the optimum is 20-23°C.

(5) Separation of larvae The hatching time of the fertilized eggs varies depending on the species and water temperature

However, it usually takes 5-10 days. Its larvae may have a difference of 96 hours before and after hatching.

To ensure the quality of first hatched larvae, the hatched larvae should be separated from unhatched eggs in time.

The specific method is to stop the air and water first, and after the hatching and sinking of the fertilized fish and the larvae go up, use a barrel.

Water removes all larvae.

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