In the cultivation of South American white shrimp, the preparatory work before stocking the shrimp is a crucial step that determines the success or failure of the entire year's farming. A scientific and standardized process not only significantly increases the survival rate of the shrimp larvae but also lays a healthy foundation for their subsequent growth.
1. Thoroughly clean and disinfect the pond
Soil aeration and exposure to sunlight:
Drain the water from the pond and thoroughly remove the sediment at the bottom (especially for ponds that have been in use for many years)
Till and expose it to the sun for 15 to 20 days until the bottom soil cracks and fully oxidizes and decomposes the organic matter.
Scientific disinfection:
Calcium oxide disinfection: Use 75-100 kilograms per acre. Mix it into a slurry and sprinkle it throughout the entire pond to kill the pathogens.
Chlorine-based disinfection: The effective chlorine content reaches 10-15 ppm.
After disinfection, expose it to sunlight for 7 to 10 days to ensure that the efficacy of the medicine is fully exerted.
II. Precise Water Quality Control
Water quality indicators meet standards (tested and adjusted 3-5 days before stocking):
pH value: 7.8 - 8.6 (daily fluctuation less than 0.5)
Salinity: The salinity difference from the nursery site should not exceed 3‰.
Water temperature: Stabilized at above 22℃ (with a temperature difference of less than 2℃ compared to the temperature at the nursery site)
Total alkalinity: ≥ 80 mg/L
Ammonia nitrogen, nitrite: Not detected
Transparency: 30 - 40 centimeters
Rearing natural food sources with abundant water:
After disinfection, fertilization and water supply begin after 7 days. This helps cultivate high-quality algae such as diatoms and green algae.
Use fermented organic fertilizer combined with compound probiotics to cultivate zooplankton such as rotifers and cladocerans.
The water color is best when it is a shade of brownish tea or a light greenish yellow.
III. Selection of Shrimp Larvae and Water Testing
Key points for selecting shrimp fry:
Choose a legitimate seed farm and check the production license and quarantine certificate.
Observe the seedlings: They are of uniform size (0.8 - 1.0 cm), vigorous in vitality, and with well-filled digestive tracts.
Adaptability test: After being removed from water for 30 seconds and then returned, it can quickly recover.
Trial operation:
Two days before releasing the fry, place 30 to 50 fry shrimp in each net cage and then put them into the pond.
After 24 hours of observation, the survival rate must be above 95% before the fish can be released.
At the same time, test whether the water quality indicators remain stable.
IV. Details of Seed Placement Operation
Optimal seeding time:
Choose a sunny day, between 8-10 a.m. or 5-7 p.m.
Avoid strong sunlight, strong winds and heavy rain during noon.
Scientific pre-germination treatment:
The bamboo bags float on the water surface for 15 to 20 minutes to stabilize the water temperature.
Gradually add the pool water to balance the salinity and pH value.
Thirty minutes later, the shrimp larvae swam freely into the pond.
Appropriate stocking density:
Rough-cared breeding mode: 30,000 - 50,000 fish per acre
Medium-scale breeding: 50,000 - 80,000 fish per acre
High-level pond intensive farming: 15-25 thousand fish per acre
(Adjusted according to the facility conditions and technical level)
V. Preparation of Auxiliary Facilities
Oxygenating machine configuration: At least 0.75 kilowatts per acre, with pre-test run.
Set up a feed observation platform to facilitate early observation of feeding.
Prepare the rapid water quality testing kit for routine monitoring.
Stress protection product reserves: Vitamin C, calcium and magnesium supplements, etc.
Key Reminder: Management Points 3 Days After Seed Placement
No feeding or less feeding: mainly feed on natural food sources
Not changing the water: Maintaining the stability of the environment
Do not use an oxygenator (unless there is oxygen deficiency): reduce stress
Daily morning and evening pond inspections: observing the activities and survival conditions of the shrimp larvae.