When releasing crab seedlings, a series of meticulous measures need to be taken to ensure their survival rate and subsequent growth status. Here are some key steps and precautions: 1. Preparation before release
1. Crab pond cleaning: Before releasing, thoroughly clean the crab pond, including dry pond, sun exposure or freezing the bottom of the pond, to kill pathogenic organisms- Repair the pond embankments, embankments, and anti escape equipment to ensure the integrity and safety of the crab pond- Use drugs such as quicklime and bleach for pond cleaning and disinfection to kill harmful organisms such as wild fish, frog eggs, tadpoles, aquatic insects, snails, clams, crabs, etc., and improve water quality.
2. Water grass planting: - According to production needs, transplant aquatic plants such as Elodea, Kudzu, and Haematococcus. It is recommended to choose multiple varieties of compound water grass to achieve better results- Water grass planting should be carried out in advance to ensure that the water grass has grown well before releasing the crab seedlings, providing a suitable habitat and foraging environment for the crab seedlings.
3. Water quality management: Before release, the water quality is tested and adjusted to ensure that it meets the needs of crab seedling growth- Water quality can be improved by applying biofertilizers, cultivating algae, and other methods to enhance dissolved oxygen and transparency in the water. 2、 Crab seedling selection and transportation
1. Crab fry selection: - Select crab fry with neat specifications, strong physique, strong activity, and sensitive response- Avoid selecting crab fry with injuries, residual limbs, unclear esophagus, unclear gill filaments, or abnormal liver and pancreas color.
2. Crab fry transportation: During the transportation of crab fry, it is important to maintain appropriate temperature and humidity to avoid compression and damage to the fry- If the transportation time exceeds 1 hour, it should be controlled within 8 hours, and appropriate water spraying should be carried out to moisturize during transportation. 3、 Free range process
1. Release time: - Choose to release crab seedlings in sunny, stable weather with little temperature change- Spring is the concentrated period for releasing crab seedlings, but the specific release time needs to be determined based on the local climate and the growth of crab seedlings.
2. Free range density: Determine the free range density based on factors such as pond conditions, expected market time and specifications, technical management level, and breeding mode- Generally, 800-1200 crab seedlings are released per acre, but the specific quantity needs to be adjusted according to the actual situation.
3. Release method: Before releasing, soak and disinfect the crab seedlings in an aqueous solution container containing potassium permanganate or anti stress drugs to improve their survival rate- After disinfection, gently place the crab seedlings into the crab pond to avoid startling and damaging them. 4、 Subsequent management
1. Water quality monitoring: After release, regular monitoring of water quality changes and timely adjustment of water quality management measures should be carried out- Maintain water transparency between 30-50 centimeters to increase water temperature and dissolved oxygen content.
2. Feeding management: Determine the feeding amount and frequency based on the growth of crab seedlings and weather changes- When feeding, the principle of reasonable combination of fine, green, and coarse should be adhered to to to ensure that the crab seedlings receive sufficient nutrition.
3. Disease prevention and control: Regularly inspect the growth of crab seedlings, promptly detect and address disease issues- Low irritant disinfectants can be used for whole pool spraying and disinfection to reduce the occurrence of diseases.
4. Anti escape facilities: Ensure that the anti escape facilities are intact and prevent damage caused by the escape of crab larvae.
Adequate preparation and meticulous management measures are required when releasing crab seedlings to ensure their survival rate and subsequent growth status.