Key Techniques for Reducing the Casualties of Parental Fish

The main factors leading to the casualties of parent fish in spawning are as follows: first, the physical consumption of parent fish in the process of spawning and reproduction, coupled with the side effects of spawning drugs, reduce the resistance of parent fish. If the fish is injured and the pathogen is infected, it is easy to cause disease. Second, the poor physique of parent fish, or the large range of changes in water temperature during spawning, as well as the improper dose of drugs for spawning, parent fish can not spawn normally, resulting in their own physiological activity imbalance and death. Therefore, in production, we should not only pay attention to the prenatal cultivation of parent fish, so that the gonadal development of parent fish is normal and mature and have a strong physique, but also pay attention to the operation of spawning and postpartum nursing.

First of all, we should pay attention to fishing operations.

Whether it is the parent fish pond or pulling the parent fish from the spawning pond, the action of pulling the net should be fast and coordinated, close the net as soon as it is close to the shore, and avoid injury caused by the parent fish colliding with the pond wall. When the clear day temperature is high and the distance between the parent fish pond and the spawning pond is long, it is best to draw the net early in the morning or evening to prevent the parent fish from being injured by hypoxia in the fish stretcher. To choose a good physique and gonadal maturity of the parent fish to induce labor, do not use high-dose drugs to induce labor.

Secondly, the parent fish after spawning should be examined one by one.

All female parent fish with enlarged abdomen should gently press their abdomen with their hands to help them produce mature eggs in the abdomen. If the parent fish is difficult to give birth due to the blockage of the reproductive pore, the clogged reproductive hole can be cut and expanded with sterilized scalpel scissors to allow the mature fish eggs to be excreted out of the body, so as to prevent the mature eggs from absorbing and expanding in the belly of the parent fish and endanger the parent fish. For parent fish with body surface injuries, first wipe the wound with skimmed cotton, then wash the wound with potassium permanganate solution or iodine tincture, and then apply sulfonamide antibacterial and anti-inflammatory ointment to the wound with fingers from the tail of the fish to the head. Parent fish after induced delivery, regardless of whether they are injured or not, should be injected with appropriate amount of anti-inflammatory drugs.

Third, the pond of parent fish after spawning needs to be sterilized with quicklime first.

The water in the pond should be fresh and fresh, with a depth of about 1.5 meters. It is best not to apply organic manure in the first month after the postpartum parent fish goes into the pond, and disinfect and sterilize regularly. After going down to the pond for about 5 days, parents can be fed with grain sprouts, malt or bran cakes, and grass carp can be fed with an appropriate amount of fresh and tender grass. Generally change a small amount of new water in 3 to 5 days to stimulate the appetite of parent fish and make them recover quickly.