Don't forget to protect the parent fish in order to induce labor.

Reducing the death of spawning parent fish is an important technical work for fish fry producers. In the production practice, we found that there are two reasons for the death of parent fish: first, the physical exertion 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 seriously injured, a variety of pathogens will take advantage of the opportunity to infect the fish and cause disease, resulting in the death of the parent fish. Second, the physique of the parent fish is poor, the gonadal development is poor, or the water temperature changes greatly during the induction of labor, and the dosage of the drug is too high or too low, so the parent fish can not spawn normally or have dystocia, which leads to the imbalance of their own physiological activities and death. Therefore, in production, we should focus on the nursing work before and after labor induction.

First of all, we should pay attention to fishing operation, which is an important part of reducing the casualties of parent fish. No matter in the parent fish pond or in the spawning pond, the operation of pulling the net should be brisk and coordinated. As soon as the net reaches the shore, the net is quickly closed, and after setting up the net, the parent fish in the net is quickly dragged away from the shore to avoid the parent fish hitting the wall. When it is sunny and hot and far away (the distance between the parent pond and the spawning pond), it is best to fish early in the morning or evening, and to prevent the parent fish from being suffocated by hypoxia in the fish stretcher.

Secondly, when catching parent fish after spawning from the spawning pond, check them tail by tail. All female parent fish with enlarged abdomen should gently press their abdomen to help them produce mature eggs in the abdomen; if the parent fish is difficult to give birth due to blockage of the reproductive pore, it is necessary to use sterilized surgical scissors to cut and expand the blocked reproductive hole and let the mature eggs be excreted out of the body, this can prevent the mature eggs from absorbing water in the parent fish and endangering the parent fish (this is one of the main causes of death of the female parent fish after induced spawning). For parent fish with body surface injuries, first dry the wound with skimmed cotton balls, then wash with potassium permanganate solution or malachite green solution containing 1% salt, and then apply sulfonamide ointment or erythromycin, tetracycline and other anti-inflammatory ointment on the wound with fingers from the tail to the head; for parent fish with inflamed, swollen furuncles and sores, wipe the focus with skimmed cotton balls first, then apply iodine, and then apply anti-inflammatory ointment. All parent fish after induced delivery, whether injured or not, are injected with 1 ml of sulfonamides (containing 0.2 grams of drugs) or other anti-inflammatory drugs per 5-8 kg of body weight.

The pond where the parent fish are released to induce spawning shall be disinfected with quicklime. The water in the pond should be fresh, and the water depth should be about 1.5 meters. Organic fertilizer should not be applied within the first month after spawning, and regular disinfection and sterilization of medicine solutions such as bleach, strong chlorine, fish and shrimp an should be sprinkled to prevent and cure fish diseases. The parent fish began to feed in the pond for about 5 days, mainly feeding the grain sprout, malt, bran cake or compound feed that the parent fish like to eat, while the grass parent fish should be fed with an appropriate amount of fresh and tender grass. Generally change part of the fresh water in the pond in 3-5 days, adjust the water quality, stimulate the appetite of the parent fish, make it recover quickly and enhance the resistance.