Cultivation techniques of lobster seedlings

Lobster culture shrimp fry cultivation is the focus, although lobster almost perennial mating, but every spring as the peak, mating generally in the open area of the water, mating temperature range is large, from 15℃ to 31℃ can be carried out, reproduction is special, most of the process is completed in the cave, so in the ordinary production is difficult to see eggs shrimp, so pay attention to strengthen management.

Lobster parent selection

The parent shrimp can be selected from March to October of the same year, with a weight of 20~25 grams, complete appendages, healthy and disease-free, strong activity, and a male to female ratio of 1:1 (obtained from actual breeding experience). Male and female lobsters have obvious characteristics in appearance and are easy to distinguish. The male individual of sexually mature lobster is obviously larger than that of female, male dragon foot is thick, there is a bright red soft wart on the outer side of both ends of dragon foot, female is pale even if there is color, male genital hole opens at the base of the fifth pair of feet, female genital hole opens at the base of the third pair of feet, sexually mature female shrimp abdomen is enlarged, male shrimp abdomen is relatively narrow.

Lobster parent culture

1. Shrimp pond construction: the area of parent shrimp pond is about 2~5 mu, the substrate is good with loam, the water depth is more than 1~1.5 meters, there is sufficient and good water source, the injection and drainage outlets are built, the surrounding pond ridge is built with plastic film or calcium plastic plate to prevent escape, and the pond is disinfected with 50~80 kg/mu quicklime dry pond 7~10 days before stocking. After disinfection, filtering (to prevent wild fish from entering the pond) and injecting water, 100~200 kg/mu of decomposed livestock manure is applied to improve the water quality. The pond is filled with shelters for shrimp climbing, such as branches, roots, bamboo tubes, etc., and some aquatic plants are transplanted.

2. Parent shrimp feeding: 40~60 kg/mu of parent shrimp can be put into the parent shrimp pond. Before stocking, soak in 3% saline for 10 minutes to kill pathogens. In order to make full use of water and regulate water quality, silver carp and bighead carp can be mixed cultured at 50~100 fish/mu. During the cultivation period, fresh aquatic plants, bean cakes, wheat bran or compound feed can be fed, and a part of animal feed can be added. Such as chopped snail meat, livestock and poultry slaughter waste, etc.

3. Daily feeding amount: generally 2~3% of parent shrimp weight in March, 4~5% in April, 6~8% after May, feeding once a day in the morning and evening, mainly in the evening, accounting for 70% of the daily feed amount. At the same time, strengthen water quality management, change fresh water once every 10~15 days, change water 1/3 every time, sprinkle water with quicklime 5~10 kg/mu once every 20 days, increase soil calcium to maintain good water quality and promote gonad development of parent shrimp.

Lobster reproduction overwintering

1, parent shrimp reproduction: usually April to May when the water temperature above 20℃ parent shrimp began to mate. The fertilized eggs hatch into juvenile shrimp in the abdomen of female shrimp, and the incubation time takes 40~70 days. After hatching, the juvenile shrimp completes the growth and development process of the juvenile shrimp stage under the protection of the mother. As soon as the young shrimp leave the mother, they can take the initiative to feed and live independently. When a large number of young shrimps are found in the breeding pond, they should be collected in time for shrimp seedling cultivation.

2. Parent shrimp overwintering: The lowest survival water temperature of lobster is 5℃. When the water temperature is lower than 0℃, the mortality rate of shrimp about 3 cm during overwintering is very high. Although adult shrimp can survive, a large number of deaths will occur after 2~3 months. Therefore, raising the water level to do a good job of overwintering parent shrimp and ensuring the water temperature during overwintering are also important links in the whole breeding work.

Lobster breeding technique

Lobster eggs are generally 200~800, fertilization rate can be above 98%, hatching rate can reach 80~85%. The problem is that the larvae molt frequently after emergence, which is easily restricted by environmental conditions and affects the seedling rate. To improve the seedling rate, the key points are as follows:

1, water quality requirements: lobster breeding period, to keep the water relatively stable, fresh water quality, pH value between 6.5~8, to prevent the temperature difference between day and night is too large, dissolved oxygen in the water should be maintained at 5.6 mg/L or more.

2. Water environment: There must be aquatic plants at the bottom of the water surface (water lotus, water peanut, green algae, verticillata, etc. account for 1/3), and hidden caves to increase the molting attachment of shrimp seedlings. It is also convenient to master the emergence time and shrimp growth through the washing of water lotus seedlings. Fence and filter net are added to the water inlet to prevent harmful organisms from entering the pool, and frogs from entering the pool to lay eggs, so as to avoid tadpoles from eating shrimp seedlings. At the same time, it is necessary to prevent the parent shrimp from climbing and escaping.

3. Strengthen inspection: insist on checking the emergence situation in the morning and evening. When the young shrimp is free from the mother, catch the parent shrimp in time and return to the parent shrimp pond for re-cultivation. Try to reduce the inventory of the pond. The operation should also be especially careful to avoid affecting the hatching of the parent shrimp.

4. Ensure feeding: culture rotifers and other small zooplankton in due time for feeding on newly hatched shrimp. It is estimated that 3~5 days before emergence, a small number of small zooplankton will be caught from the special incubation pond and put into the shrimp nursery pond. And with cooked egg yolk, soy milk and other timely supplement young, young shrimp required food supply.