The green shrimp meat is delicious, the market demand is large, the first is higher, and it is a precious aquatic product welcomed by the masses. However, artificial large-scale breeding of green shrimp seedlings has always been a bottleneck restricting the development of the industry, and the self-breeding and self-breeding of green shrimp seedlings is the fundamental way to do a good job in shrimp production, and the correct mastery of breeding technology is the basis of self-breeding and self-breeding.
1. Spawning period of green shrimp.
The water temperature required for spawning of broodstock shrimp is above 18. In the middle and lower reaches of the Yangtze River, from mid-April to mid-September, June and July are the peak spawning seasons, and from mid-June to mid-July.
2. Green shrimp spawning and hatching.
In the spawning population, the broodstock that spawn in June and July are larger, which are the older shrimp that have been overwintered;Broodstock that spawn after July are smaller, and they are shrimp that grow after breeding that year. The whole process of spawning and hatching takes place in the cage. There are two types of cages: incubators and incubators.
The incubator is made of polyethylene mesh with a mesh of 196 square centimeters, and the size is 10 meters 667 meters 17 meters, the bottom of the box and the upper mouth of the box are respectively equipped with a polyethylene bar rope, the cage is open floating, and the cage is 0 3 meters exposed to the water surface when installed, to prevent the escape of shrimp.
The box is placed for the hatching of wood dyed small cage 1 2, made of polyethylene mesh with a mesh of 12 square centimeters, the specification is 1 7 meters * 1 meter * o 5 meters, the cage is installed to expose the water surface 5 cm, and at the bottom of the box four corners each tie a small brick.
Broodstock should be moved to an incubator for fattening before spawning. When the water temperature reaches 18, the broodstock will mate, and the eggs are usually laid within 24 hours after mating. When the female shrimp is in labor, the abdomen is stretched and flexed, and the back is raised.
The eggs produced are oval in shape, with a lot of yolk, and are attached in clumps to the bristly abdomen of the female shrimp and 4 pairs of appendages. After wintering, the old shrimp can spawn 2 times in a row, the second spawning is after the hatching of the eggs laid for the first time, the number of eggs laid by the green shrimp is related to the age and body length of the broodstock, the old shrimp after wintering, the spawning can reach up to 5000 grains, and the shrimp that reproduces mature in the year, the body length is 3 cm, and the spawning is only about 700 grains at most.
When the eggs have compound eyes, the egg-holding female shrimp should be placed in small hatchery cages, with 700 1000 shrimp per cage. After 6 or 7 days, the larvae can break through the membrane and break away from the broodstock and fall into the incubator. At this time, the incubator should be taken out of the cage together with the broodstock that have laid eggs.