Fertilization Method
(1) Select white-tailed pike with a maturity age of 2+ years, weighing between 700 and 1000 grams, as broodstock. These fish should be healthy and in optimal condition for breeding.
(2) Dry insemination is the preferred method. After collecting the eggs, they are placed into a dry container without contact with water to prevent premature swelling. A cloth is used to gently wipe the fish before extracting the eggs. Talcum powder is then applied to reduce adhesion and improve handling. It’s crucial to avoid any exposure to water during this process, as it can negatively impact fertilization success.
Fertilization Process
(1) The first three days after fertilization are critical, as the sperm-egg binding is still unstable. Stirring should be avoided to ensure proper development.
(2) Maintain a pH level between 7.5 and 8. If the pH drops below 7.5, use analytical-grade sodium bicarbonate to adjust it. This helps create an optimal environment for egg development.
Incubation
(1) The incubation density should be between 150,000 and 300,000 eggs per square meter in the hatchery frame. Proper spacing ensures good water circulation and reduces disease risk.
(2) Incubation should take place in low-light conditions. The first two days are sensitive periods, so light and vibration must be minimized. During hatching, the color of the eggs changes from yellow to yellowish green and finally to dark brown due to pigment changes in the embryos. Newly hatched fry have an adhesive area on the back of their heads, which allows them to stick to surfaces like the bottom of the hatching tray or cage walls.
(3) Temperature should be increased gradually, no more than 0.5°C per hour, to avoid stress on the developing eggs. Ideal water temperature for incubation is between 8°C and 12°C, with dissolved oxygen levels maintained at 7–9 mg/L.
(4) Regularly clean and inspect all screens around the hatching box and outlet filters to ensure unobstructed water flow.
(5) In the early stages of incubation, reduce water flow to prevent the eggs from being displaced. Excessive water movement can lead to egg mortality.
Emergence
(1) As soon as the fry emerge, remove them promptly from the hatching tray. Be careful not to let the fry sink along with the egg membranes, as this can cause suffocation.
(2) Adjust the stocking density in the seedling pool based on the growth of the fry. Overcrowding can lead to oxygen depletion and high mortality rates.
(3) Use running water in the seedling pool to maintain water quality and oxygen levels. If necessary, supplement with aeration, but avoid over-oxygenation, as it can harm the fry and cause congestion and death.
Seed Stocking
(1) Choose healthy, strong, and uniformly sized white-spotted dogfish fry with no signs of disease or injury. Quality selection is key to successful rearing.
(2) Disinfect the fry by dipping them in a 3% to 5% saltwater solution for 3–5 minutes. This helps prevent infections such as watery disease and improves survival rates.
Antibacterial Ingredients
The following are some antibacterial ingredients such as Turmeric, White Willow Bark Extract, Quercetin Dihydrate
, White Willow Bark Extract Salicin, Matrine and their classification and main applications:
1. Silver ion: has a broad spectrum antibacterial effect, often used in antibacterial textiles, medical equipment,t and so on.
2. Quaternary ammonium salt: can kill a variety of bacteria, commonly found in disinfectants, antibacterial fabrics, etc.
3. Chitosan: has an inhibitory effect on a variety of bacteria, and has applications in antibacterial dressings, food preservation, etc.
4. Plant extracts, such as berberine (berberine), allicin, etc., have certain applications in antibacterial products.
5. Triclosan: Widely used in personal care products.
6. Nanometer zinc oxide: has antibacterial properties, and can be used in antibacterial materials.
7. Propolis: has a certain antibacterial effect and is used in some products.
8. Lysozyme: can break down the bacterial cell wall, and play an antibacterial effect.
9. Tea tree oil: has an inhibitory effect on a variety of bacteria
The main effects of these antibacterial ingredients include:
1. Inhibit or kill bacteria: Reduce the number of bacteria to prevent bacterial infection and spread.
2. Maintain hygiene: Keep the environment and items clean to reduce the risk of bacterial growth.
3. Protect human health: reduce the damage of bacteria to the human body and prevent disease.
Turmeric,White Willow Bark Extract,White Willow Bark Extract Salicin,Matrine,Quercetin Dihydrate
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