Crayfish seedling cultivation technology where can I buy crayfish seedlings

The crayfish is very shrimp-like and its carapace is very hard. And crayfish are very adaptable. Especially in the period of its breeding, he especially likes to dig holes. Crayfish are omnivores. He likes to eat dirt under the water, or small fish that have died. So how should he cultivate crayfish? Let's have a look together.

Cultivation techniques of crayfish seedlings

First, parent shrimp selection

Parent shrimp can be selected in September-October of last year or March-April of the same year, with a body weight of 30-50g, complete appendages, health and disease-free, strong activity, and a female-to-male ratio of 2-3:1. Male and female lobsters have obvious characteristics in appearance and are easy to distinguish. For sexually mature lobsters, the male individual is significantly larger than the female; the male dragon foot is thick, there is a bright red molluscum on the outside of both ends of the dragon foot, the female dragon foot is relatively small, most of the female feet do not have red molluscum, even if there is a light color; the male dragon foot is thick, there is a bright red molluscum on the outside of the dragon foot, the female dragon foot is relatively small, and most of the female feet do not have red molluscum, even if there is a light color. The reproductive foramen opening is at the base of the fifth pair of feet in male and at the base of the third pair in female; the abdomen of sexually mature female shrimp is dilated and the abdomen of male shrimp is relatively narrow.

Second, parent shrimp cultivation

The main results are as follows: 1. The area of parent shrimp pond is about 1200m2, the bottom material is loam, the water depth is about 1m, the ridge width is more than 1.5m, there is sufficient and good water source, the injection and drainage outlet is built, the surrounding ridge is built with plastic film or calcium plastic board to prevent escape wall, and the pond is disinfected with 50-60kg/ per mu raw lime dry pond 7-10 days before stocking. After disinfection, the depth of water injection was about 1m after filtration (preventing wild mixed fish into the pond), and 500-800kg/ mu of rotten livestock and poultry manure was applied to improve the water quality. Put people in the pond for shrimp climbing shelter, such as branches, roots, bamboo tubes, etc., and transplant some aquatic plants.

2. Parent shrimp ponds can be put into 40-60kg/ mu of parent shrimp and soak in 3% salt water for 10 minutes before stocking to kill pathogens. In order to make full use of the water body and regulate the water quality, 50-100 silver carp and bighead carp can be mixed cultured at the same time. During the cultivation period, fresh water plants, bean cakes, wheat bran or formula feed can be fed, and some animal feed can be added. Such as chopped snail clam meat, livestock and poultry slaughtering scraps and so on. Daily feed: 2% of the body weight of parent shrimp in March, 4%-5% in April, 6%-8% after May, once in the morning and once in the evening, accounting for 70% of the daily diet. At the same time, the management of water quality should be strengthened, changing fresh water once every 10-15 days, and sprinkling 10-25g/m2 with quicklime every 20 days to maintain good water quality and promote gonadal development of parent shrimp.

3. Breeding of parent shrimp

From April to May, when the water temperature is above 20, parent shrimp begin to mate. The fertilized eggs are hatched into young shrimps in the belly of female shrimp, and the incubation time is 40-70 days. After hatching, the juvenile shrimp completed the growth and development process under the protection of the mother. As soon as the juvenile shrimp leaves the mother, it can take the initiative to feed and live independently. When it is found that there are a large number of young shrimp in the breeding pond, the seedlings should be collected in time for shrimp seedling cultivation.

4. Parent shrimp overwintering

The lowest survival water temperature of lobster is 5 ℃. However, when the water temperature is lower than 9 ℃, the mortality rate of shrimp about 3 cm is very high during the overwintering period. Although adult shrimp can survive, there will be a large number of deaths after 2-3 months. Therefore, to do well the overwintering work of parent shrimp and ensure the water temperature of 16 ℃-18 ℃ during the overwintering period is also an important part of the whole breeding work. The commonly used overwintering methods include plastic film covered pool insulation method, electric heater heating method, hot spring water overwintering method, factory residual hot water overwintering method and glass chamber overwintering method, which can achieve the safe overwintering effect of parent shrimp.

5. Seedling raising techniques

Although the number of eggs held by lobsters is small, the fertilization rate can be more than 98%, and the hatching rate can reach 80% to 85%. The problem is that the young shrimp grow and molt frequently after emergence, which is easily restricted by environmental conditions and affect the breeding rate.

Where can I buy crayfish saplings

The strong adaptability of crayfish can be raised in most areas of the country, can be selected and purchased according to the nearest principle, and the combination of local and off-site seedlings. Crayfish culture in rice fields in the same region, through self-propagation for a long time, is in multi-generation inbreeding, its genetic genes become weak, appear precocious, small and other germplasm degradation phenomena, its disease resistance is weak, easy to infect various diseases. Therefore, it is appropriate to screen and introduce some shrimp seedlings from other places (preferably outside the province). Enter the seedlings early. Shrimp seedlings are introduced at the end of March every year, so that crayfish can adapt to the breeding environment, feed early and reach the market specifications as early as possible. The imported shrimp seedlings should have the advantages of large size, high survival rate, short culture cycle and quick effect. Shrimp fry imported in the same batch should have neat specifications and complete limbs. Some experiments show that during the period of raising seedlings in winter, using biological fertilizer and biological feed to cultivate shrimp seedlings can achieve the goal of early emergence of shrimp seedlings, neat specifications and strong physique.

What needs to be done to improve the breeding rate of crayfish

1. Water quality requirements: during the lobster breeding period, the water body should be relatively stable, the water quality should be fresh, and the pH value should be between 6.5 and 8; the temperature difference between day and night should be prevented; and the dissolved oxygen in the water should be kept above 5.6 mg / L.

2. In the water environment, there must be water floating lotus on the water surface (accounting for 1 to 3), and there should be water plants at the bottom and hidden caves to increase the molting attachment of shrimp seedlings, and it is also convenient to grasp the emergence time and the growth of shrimp through seedling washing inspection. Fences and filters are added to the water inlet to prevent enemy creatures from entering the pond, to prevent frogs from entering the pond to lay eggs, and to prevent tadpoles from eating shrimp seedlings. At the same time, it is necessary to prevent parent shrimp from clinging to and escaping.

3. Strengthen the inspection and insist on checking the emergence of larvae sooner or later. When the larvae are free from the mother, catch the parent shrimp and return to the parent pond in time to rebreed, so as to minimize the stocktaking through the pond, and be very careful in the operation to avoid affecting the parent shrimp holding eggs and the newly hatched shrimp.

4. Ensure feeding and timely cultivate rotifers and other small zooplankton to feed the newly hatched shrimp. It is estimated that 3-5 days before emergence, a small amount of small zooplankton will be caught from the special feed pond into the shrimp seedling pond. And use cooked egg yolk and soybean milk to replenish the food supply for young and young shrimp in time.

Disease management of crayfish

1. Vibrio problem

As the water temperature rose above 30 ℃, the crayfish white spot virus disease disappeared. However, Vibrio did not disappear, the temperature increased, the temperature at the bottom was low, and the oxygen at the bottom was also low. This environment is more suitable for the growth of Vibrio. A small number of crayfish will die or beat up.

II. Solution

1. It is suggested that the bottom of the pond should be changed regularly to reduce the oxygen consumption at the bottom and indirectly increase the dissolved oxygen at the bottom.

2. Clear the pond thoroughly and kill the pathogenic microorganisms in the pond with quicklime or bleach, strong chlorine and other pond cleaning drugs, so as to fundamentally reduce harmful bacteria and viruses.

But because the crayfish is very anti-pollution. So we can put it in the aquarium, or we can effectively remove fish feces or moss. And the protein content in crayfish is very high, so it can also be given to people who are weak.