Farmer Knowledge Hub

Thorough pond preparation between production cycles reduces disease carryover and establishes optimal conditions for new stock. Complete draining, sun drying, and bottom treatment eliminate pathogens and accumulated organic matter from previous cycles.

Lime application adjusts soil pH and provides disinfection. Dosage depends on soil conditions, typically 500-1000 kg per hectare. Allow treated ponds to dry completely before refilling to maximize pathogen elimination.

After refilling, stabilize water parameters for 7-10 days before stocking. Develop natural productivity through fertilization to establish food sources for post-larvae. Test water quality parameters daily during this preparation period.

Stocking density decisions balance production goals with management capacity and risk tolerance. Lower densities (30-50 PL/m²) reduce disease pressure and simplify management. Coastal Aquaculture Authority guidelines for Vannamei set an upper limit of 60 PL/m²; densities toward that limit need stronger aeration and closer water quality management.

Proper acclimation reduces stocking stress and improves survival. Float sealed bags in pond water for 20-30 minutes to equalize temperature. Gradually mix pond water with bag water over 30-45 minutes to adjust salinity and pH differences.

Stock during cooler parts of the day (early morning or evening) to minimize temperature stress. Release post-larvae gently into shallow areas with good water circulation. Monitor behavior for 24-48 hours after stocking to verify successful acclimation.

SPF stands for Specific Pathogen Free. It describes stock that comes from a population tested, over time and under a surveillance programme, and found free of a named list of pathogens. It is a statement about health status and history.

SPF is not the same as resistance. An SPF post-larva is free of those pathogens when it leaves the hatchery; it is not protected against them if it meets them later in the pond. That is why farm-level biosecurity still decides how a cycle goes.

Ask your hatchery which pathogens its broodstock is certified free of, and where the broodstock comes from. Under Coastal Aquaculture Authority rules, Vannamei seed must come from registered hatcheries using approved broodstock.

PCR (polymerase chain reaction) detects the genetic material of a pathogen in a sample. It finds infections before any sign shows, which is why it is the standard test for shrimp seed.

A seed report for Vannamei in India commonly covers WSSV (white spot syndrome virus), EHP (Enterocytozoon hepatopenaei), IHHNV (infectious hypodermal and haematopoietic necrosis virus) and AHPND (acute hepatopancreatic necrosis disease). Each line should read negative, with the sample date and the batch it belongs to.

A negative result describes the sample tested, on the day it was tested. Keep the report with the batch reference and your stocking records, so that if a problem appears later you and the hatchery can trace it back.

Feed quality directly impacts growth rates, feed conversion ratios, and production economics. Select feeds formulated for specific life stages with appropriate protein levels and nutrient profiles.

Protein requirements decrease as shrimp grow. Early stages require 35-40% protein, while later stages perform well with 30-35% protein feeds. Proper feed storage prevents nutrient degradation and contamination. Store in cool, dry conditions and use within manufacturer recommendations.

Feed pellet size should match shrimp size for optimal consumption. Undersized pellets waste feed through leaching. Oversized pellets reduce consumption and feeding efficiency. Transition pellet sizes as shrimp grow throughout the production cycle.

Feeding rates balance growth optimization with water quality maintenance and economic efficiency. Base feeding rates on estimated biomass, adjusting for water temperature, dissolved oxygen levels, and observed feeding response.

Multiple daily feedings (3-4 times) improve feed utilization compared to single large feedings. Distribute feed evenly across pond areas to ensure all shrimp access food. Reduce feeding during low dissolved oxygen periods or after water quality disturbances.

Check trays monitor feeding response and adjust ration accordingly. Place trays in multiple pond locations and check 1-2 hours after feeding. Complete consumption indicates potential for increased ration. Remaining feed suggests overfeeding or health issues requiring investigation.

Vannamei is the Pacific whiteleg shrimp, Penaeus vannamei (still often written Litopenaeus vannamei). It is native to the Pacific coast of Latin America, from Mexico to Peru, and is now the most widely farmed shrimp in the world.

It suits farming because it grows quickly, tolerates a wide range of salinity and temperature, and uses the whole water column, which allows higher stocking densities than the native tiger shrimp.

India permitted commercial Vannamei farming in 2009, under guidelines issued by the Coastal Aquaculture Authority (CAA), the body set up under the Coastal Aquaculture Authority Act, 2005. Within a few years Vannamei became the main farmed shrimp in the country.

The rules cover the whole seed chain. Hatcheries producing Vannamei seed must be registered with the CAA, and imported broodstock must be SPF and pass through the national Aquatic Quarantine Facility in Chennai before it reaches a hatchery.

For a farmer, the practical test is simple. Ask whether the hatchery is CAA registered, whether its broodstock is SPF, and whether each batch comes with a PCR report. At Raj Hatcheries, broodstock is SPF and every batch comes with a PCR report.