Technical points for selecting broodstock in winter
Organic Phosphonic Acid ,Diethylenetriamine Pentamethylenephosphonic Acid,Methylene Phosphonic Acid Qidi Chemical Co., Ltd. , http://www.czchemicals.com
December 07 21:02:25, 2018
The production season for large-scale catching of adult fishes in winter is an excellent opportunity to select broodstock. When broodstock is selected and retained, the following technical steps should be grasped: 1. The best temperature for catching adult fish is 4°C～10°C. At this time, the food intake of the fish is reduced and the activity is slow. The scales are not easily injured. Before feeding, it is necessary to reduce the feeding and prevent the fish from being frightened and jumped after eating, resulting in casualties. In the course of operation, if the broodstock is found to have fallen off due to a collision and the rays are broken, use a clean cloth to dry the wound, apply 3% to 4% salt water, and apply a layer of Vaseline or butter to prevent infection. Sphaerotheca. Second, the selected broodstock should reach or approach the age of sexual maturity. The general situation is: herring 7th instar, grass carp 4th to 5th instar, flower pods, white peony 3rd to 5th instar; male fish mature one year earlier than female. The weight of the broodstock is: 15 kg of herring, 6 kg to 8 kg of grass carp, 5 kg to 10 kg of calyx, 2 kg to 3 kg of white peony, and the weight of the male fish can be slightly lighter than the female. Individuals of the same age should be selected larger, because in general the larger the individual, the larger the amount of eggs, the greater the number of eggs laid. Third, the broodstock requires a healthy physique, complete scales fins, no trauma, no disease; gonadal development requirements to reach the third phase: from the appearance of the mother to see the abdomen on both sides of the abdomen has obvious ovarian bulge, if anatomy, peritoneal ovaries It is grayish blue, 2 cm wide and 15 cm long. The ratio of female to male is preferably 1:1.2 or 2:3. Female and male fish should be selected from large bodies of water, and conditions are best derived from different waters. 4. The time for catching and transporting broodstock should be carried out at night. The nylon bags can be shipped in a short distance. The nylon bags are washed and filled with water. Each bag is loaded with a broodstock, and the head of the fish is toward the mouth to facilitate breathing. Long-distance transport vehicles or ship-mounted water transport, transport applications are generally bamboo, water capacity of 0.4 cubic meters of fish, each armored broodstock 35 kg to 60 kg. Once oxygen deficiency is found on the way, it should be replaced with new water or artificial oxygen in order to avoid the death of broodstock.