Hatcheries and Nurseries

Broodstock management

Hatcheries hold mature fish or shrimp, called broodstock, under conditions that bring them into breeding readiness: appropriate temperature, photoperiod, nutrition and low stress. For Indian major carps, induced breeding using hormonal preparations and circular spawning tanks has been standard practice for decades. For whiteleg shrimp, specific-pathogen-free broodstock are imported under regulation and held in biosecure maturation units.

Spawning and larval rearing

Eggs hatch into larvae that are fragile and have specific feeding requirements. Carp hatchlings are reared on plankton in prepared nursery ponds or tanks. Shrimp larvae pass through several stages, fed on microalgae and artemia, before becoming post-larvae. Water quality, hygiene and feeding precision in this phase decide survival.

The nursery phase

Nurseries grow fry to fingerlings, or early post-larvae to a size suitable for grow-out, in protected ponds, tanks or raceways. A separate nursery phase shortens the grow-out period, reduces mortality from predators and lets farmers grade animals for uniform stocking. Recirculating nursery systems are increasingly used to deliver larger, stronger juveniles.

Judging seed quality

• Correct species identity, confirmed where mixed-species seed is common.
• Uniform size and active swimming or feeding behaviour.
• Absence of visible deformities, lesions or parasites.
• Health screening and, for shrimp, documentation of pathogen-free status where available.
• Acclimation to the farm's temperature and salinity before release.

Transport and stocking

Oxygen-packed bags or aerated tanks, cool temperatures, short journeys and careful acclimation reduce transport stress. Stocking in the early morning or evening, after equalising temperature, improves early survival.