The brooding fish chooses the key to catch seven

Production practices have proved that the selection of good broodstock is the key to artificial breeding of fry. With the increase in the number of breeding, the broodstock declines year by year, so new and new ones should be replaced each year. The key to choosing a broodstock is to do the following seven tasks.
1, time. The broodstock is best left before the Spring Festival (ie when a large number of adult fish are harvested). When catching fish, the water temperature is preferably between 6-12°C. At this time, the food intake of the fish is reduced, the activity is slow, the scales are tight, and it is not easy to be injured. If the water temperature is too high, the fish will have strong activity, loose scales, and be easily injured by the net. This will cause high oxygen consumption and inconvenience transportation.
2, age. If you buy brooders from other places, you must understand the age of the broodstock. The general age of cultured fish is: 3-4 years of age of carp, 4-5 years of carp, grass carp, more than 6 years of herring, and more than 2 years of age.
3, physical fitness. Should choose a healthy physique, complete scales fins, no disease, no traumatic fish as broodstock.
4, weight. The more broodstock the more eggs. The general body weight is: 3 kg of carp, 8 kg of carp, 7 kg of grass carp, 1 kg of carp, pupa, and carp.
5, blood relations. Experience has shown that offspring of the same broodstock show off-spring traits in offspring if they are mated, resulting in slow growth, disease, and reduced yield. Therefore, the females and males used to breed broodstock should come from different places. The distance between the two places should be as far as possible.
6, gonadal development. Selected broodstock, gonadal (ovary or testis) development requirements to reach the third phase. Two methods can be used to observe: First, from the outside, there are obvious ovary bulges on both sides of the abdomen; Second, when the fish is full, when the abdomen is raised and the appearance is not easy to judge accurately, the self-supporting fish can have several tails. Representatively, the ovaries grow on both sides of the abdomen and are grayish blue. In winter, it is better to have 2 cm wide and 15 cm long.
7, male and female identification. The ratio of male and female fish should be appropriate, generally 1:1, males can not be too much. According to the characteristics of the pectoral fins, scales and other characteristics of the fish to identify male and female fish. 1 Carp: Hold the pectoral fins (third fins) with your hands. The hand is a male fish with a rough thorn feel. The hand touches the fins smooth or the ray ends have a rough feel. 2 Carp: Touching the pectoral fins The males with shaved hands feel. The hand feels very smooth for the female fish. 3 Herring: large and long pectoral fins, small white granules protruding from the fins during the reproductive season, and males with rough hand feels; body weight, short pectoral fins, no small particles in the reproductive season, and smooth female hand fish. 4 grass carp: pectoral fin base scales small and dense, slightly sharp, long and narrow fins, the reproductive season hand feel rough for the male; pectoral fin base scales large and thin, slightly round, short and wide fins, reproductive season There are no small bulges on the fins and lids, and the females have smooth hands.
In addition, some female fish or male fish older than 2-3 years old can be reserved in the adult fish and reserved as broodstock. Male or female fish can be allocated accordingly.

Healthcare Tape

Medical Adhesive Tape,Protective Elastic Tape,Low Allergic Medical Tape,Healthcare Athletic Tape

RFX+CARE Manufacturing Co.,Ltd. , https://www.rk-rfxcare.com