Nursery Raceway (Shrimp)

A shrimp nursery raceway is a shallow, rectangular, high-flow tank or concrete channel, typically 30 to 80 cm deep, used to rear recently stocked post-larvae (PL8 to PL12) from roughly 0.01 g up to 0.3 to 2 g over 20 to 40 days before transfer to grow-out ponds. Continuous water flow or strong aeration keeps dissolved oxygen above 5 mg/L and maintains ammonia below 0.5 mg/L, while centralized or airlift-driven circulation concentrates feed and keeps shrimp evenly distributed. Stocking densities run 1,000 to 10,000 PL per cubic meter in flow-through nurseries and even higher in recirculating systems. High-protein crumble or micropellet feeds (40 to 50 percent crude protein) are fed 4 to 8 times daily, and survival commonly exceeds 80 percent under good management versus 40 to 60 percent when PL are stocked directly into large ponds. The nursery stage also allows size grading, health screening, and acclimation to farm water, and it buffers grow-out ponds against hatchery supply gaps. Central drain harvest through a catch basin or sock enables gentle, rapid collection. Capital and energy costs are real, but the nursery pays back through higher and more uniform grow-out survival, earlier and more predictable harvests, and reduced early-crop disease losses.