CATDOLL : CATDOLL: What should be prepared first before the pearl grouper is ready to hatch?

Hatching of grouper fry is a technical activity. Lack of key technology will lead to low hatching success rate. In grouper breeding technology, preparation before hatching is the most important.

1. Preparation of the hatching pool:

The hatching pond must be built indoors, with a skylight of a large enough area on the roof. A sunshade net with the same area as the window is set under the skylight to facilitate the adjustment of illumination. Most hatching ponds are rectangular cement pools with an area of ​​10-20 square meters and a depth of 1.0-1.3 meters. There is an outlet in the pond, and the drain pipe is set below the edge of the pond. The water inlet is set next to the pool. The water inlet faucet is covered with a cloth bag, which plays a role in filtering and relieving water flow when water is inlet and changed. The aeration pipe of the aeration stone is fixed to the edge of the pond and divided into 10-20 blocks. An aeration stone is filled in each block to increase oxygen.

Before spawning, clean the nursery pond first, then sprinkle 800-1000 times potassium permanganate solution on the entire pond, disinfect and sterilize for 24 hours, and finally rinse several times until the toxicity of potassium permanganate completely disappears, and then add 8% full water to the pond.

2. Hatchery water quality requirements:

The water used for seedling raising needs three treatment processes: primary filtration, secondary filtration and tertiary sedimentation. After three levels of sedimentation and filtration, natural seawater basically meets the requirements for artificial hatching and seedling raising water. The water quality of the hatching pool must meet and maintain the following standard range: dissolved oxygen per liter of water exceeds 4 mg; pH value is between 7.8-8.5. The ammonia nitrogen content per liter of water is less than 0.8 mg; salinity is 30-33. The water temperature is between 24-29 degrees Celsius. These indicators should be measured before the water is transported to the hatchery.

Hatcheries also have strict requirements for light. Sunlight cannot directly shine on the surface of the pool water. If the light is too strong, algae will multiply in large numbers and affect the growth of fry. Therefore, the light intensity should be controlled between 5000-15000 lux, especially 6000-8000 lux.

The main factors affecting the success of hatching of fish fry

1. Poor quality of fish eggs, low hatching rate, weak hatched fry and high mortality rate;

2. Severe and high-incidence diseases of neuronecrosis virus disease (rotation, floating, black body);

3. Large changes in water quality (large changes in water quality, high pH value, clear water);

4. The weather changes have a big impact (thunder, continuous rain);

5. The quality of seawater sources is getting worse;

6. The growth of moss seriously affects the survival rate;

7. Insufficient natural bait (rotifers, copepods). Artificially fed bait can easily bring pathogens, and excessive feeding can easily cause gastrointestinal diseases in fry.

Be sure to pay attention to fertilizer and water, mix the fertilizer and water together, then use products such as active carbon, then pay attention to the air pump, and also pay attention to the sealing of the air stone.

Be sure to prepare stones of appropriate density, and then pay attention to the appropriate temperature of the shed. The temperature should be controlled at around 23 degrees. Pay attention to the mix of feed, and it should also be equipped with a water oxygen machine. Be sure to pay attention to the correct mix of fertilizer and water.

I think the first thing to do is to prepare the heating rod, and the temperature must be strictly controlled so that the fish eggs can hatch smoothly.