Crayfish Farming Tips: How to Prevent Escape, Cannibalism and Fry Death

In recent years, due to the booming crayfish market, combined with the crayfish's strong disease resistance, fast growth, strong reproductive capacity and adaptability, ability to overwinter naturally, and high survival rate during live transport, many people are eager to try crayfish farming. However, in the process of crayfish farming, there are still many points to pay attention to, so how do you prevent escape, cannibalism and fry death when farming crayfish?

1. How do you prevent escape when farming crayfish?

1. Persist with pond patrol inspections

Patrol once in the morning and once in the evening each day to check the crayfish's feeding and activity conditions, whether the water quality and pond are leaking, and so on, and promptly remove algae from the pond; frequently check the filter screens at the inlet and outlet to prevent crayfish from escaping or harmful organisms such as wild trash fish from entering due to broken filter screens; pay attention to whether there are harmful organisms in the pond, such as water rats, water snakes, water birds, frogs and fish pests, and if there are any, remove them promptly.

2. Observe changes in water quality

Strictly prevent water quality from being polluted by industry and agriculture; when dissolved oxygen in the water is low, the water quality is aging, or when there is muggy weather, continuous rainy weather or other severe weather, reduce the feeding amount or stop feeding; if crayfish are found to react slowly, gather by the shore, gasp at the surface and climb toward the bank, promptly add water or turn on the aerator; frequently add fresh water to keep the pond water clean and sanitary; regularly disinfect the crayfish pond with quicklime.

3. Take good anti-escape measures

For ponds used to farm crayfish, use materials such as plastic film or calcium-plastic boards to build a 50cm-high anti-escape wall. Especially during flood season and typhoon season, do a good job of flood control, and strictly prevent strong winds and heavy rain from washing away the field ridges or flooding to trigger escape.

4. Strengthen molting management

During the molting period, measures such as feeding and changing water should be used to promote synchronized molting of the crayfish. When a large number of crayfish are molting, reduce feeding and reduce human disturbance; all operations should be careful and cautious to create a quiet and good environment and promote smooth molting of the crayfish. After a large number of crayfish have molted, promptly increase the feeding of high-quality bait to prevent cannibalism caused by insufficient bait. At the same time, plant 10-15% aquatic plants and hiding structures in the shallow areas at the pond edge to create an environment for crayfish to inhabit and molt, which can also reduce cannibalism.

5. Strictly prevent crayfish from burrowing

Crayfish have the habit of burrowing, and the burrows are usually less than one meter deep, damaging the field ridges, which gives many farmers a headache. The following measures can be taken:

(1) Lay a layer of fine-mesh plastic netting on the slope of the pond ridge, which both protects the slope and prevents burrowing;

(2) Plant more aquatic plants in the pond, not too concentrated but scattered, and set up a certain number of net pieces, or set up artificial caves such as bamboo tubes and plastic tubes, to increase hiding places for crayfish to inhabit and molt, thereby reducing crayfish burrowing.

2. How do you prevent cannibalism when farming crayfish?

1. Pay attention to farming density

During high-density farming, increase the placement of hiding structures and establish artificial caves. When farming crayfish, in order to pursue higher profits, farmers often use high-density farming. When the crayfish farming density is too high, aquatic plants must be placed into the water, which on the one hand can increase hiding structures and prevent crayfish cannibalism.

2. Provide sufficient feed

Crayfish are omnivorous animals and can eat both plant-based bait and animal-based bait. Crayfish are rather voracious, and when bait is insufficient, cannibalism often occurs among crayfish. Therefore, during the farming process, it is necessary to ensure that the crayfish have sufficient bait. In addition, crayfish are the type of animal that hides by day and comes out at night, often emerging at night to move and feed. Therefore, during feeding, attention should be paid to reasonably matching the feeding amounts of the morning and evening feedings. Usually, the nighttime feeding amount should be about 60% of the total daily feeding amount.

3. Maintain water quality

Many farmers mistakenly believe that wild crayfish often live in stinking ditches, ponds and other places. They have strong pollution tolerance and can survive under relatively poor water quality conditions. In fact, this is not the case. Crayfish also have certain requirements for water quality, and excessively poor water quality conditions can cause cannibalism among crayfish.

4. Unify the size specifications of crayfish farming

Some farmers do not pay special attention to the size specifications of crayfish during the farming process. When stocking crayfish fry, the sizes are not uniform, with some large and some small, which is very unfavorable for farming, because cannibalism among crayfish is very obvious, and large crayfish eating small crayfish often occurs.

3. How do you prevent fry death when farming crayfish?

1. Select good fry

After arriving at the fry supply site, first observe for one to two days to see whether there are dead crayfish in the pond, whether the fry are already diseased, and whether their vitality is strong. These must all be understood when deciding to bring in the other party's fry. The sources of crayfish fry are relatively broad and can be divided into four types: self-breeding and self-raising, self-catching, purchasing wild fry, and buying domestic-raised fry. Large-scale farming mostly buys domestic-raised fry externally, while small-scale farming mainly relies on the first three types. Self-bred and self-raised fry are the best, domestic-raised fry are next, self-caught fry are next, and wild fry are the worst.

2. Standardize operations

Strictly operate the pond environment itself according to procedures. 15 days before stocking fry, remove wild trash fish; 5 days before, kill insects; 4 days before, fertilize the water; 3 days before, sterilize and improve the bottom; 2 days before, detoxify and test the water. Being non-toxic and harmless before stocking is the key to ensuring the survival rate of healthy crayfish fry after they enter the pond.

When transporting fry, first lay a layer of aquatic plants on the bottom of the frame; the thickness of the crayfish fry layer should not exceed 5 cm, and they should arrive at the stocking site before 4 a.m. Choosing clear, fine weather for bringing in fry is key; it is not recommended to bring in fry on cloudy days, and it is opposed to bringing in fry on rainy days. When stocking fry, soak them in medicine for 3-5 minutes.

Place the fry frame together with the crayfish fry into the water for 2 minutes, lift it out of the water and set it aside for 2 minutes, and repeat this cycle two to three times. When stocking the fry into the water, drag and pour them along the perimeter of the pond, and a portion can also be distributed in the shallow water areas of the pond. It is strictly forbidden to pile them up and pour them in one place. While stocking the fry, in the stocking area, directly sprinkle granular oxygen-increasing agents in the fry-stocking area, and splash vitamin C and glucose-type drugs.

After stocking the fry, on the second day, splash vitamin C and glucose-type drugs, and trial-feed bait. On the fourth day, supplement calcium and magnesium once. If no molting is seen on the fifth day, supplement calcium and magnesium once again.