Shrimp in Aquaculture

Presentation by Karen Jensen Marine Aquaculture 2013 Shrimp in Aquaculture

Common Saltwater Species • Whiteleg shrimp • Penaeusvannamei • Family Penaeidae Giant tiger prawn Penaeusmonodon

Economic importance • World production of captured and farmed shrimp is ~6 million tons • 25-30% of worldwide saltwater shrimp production is in ponds • Texas produces the most of any state- 8 million lbs in 2001 • Florida has the largest hatcheries • Penaeusvannamei aquaculture has boomed in recent years • 2011: 2,877,542 tons produced • Market price decreasing, 3-3.5 USD/kg in 2005 • Main suppliers to US: Thailand, Ecuador, India, China, Vietnam • Penaeusmonodon • 2011: 662,453 tons produced • Market price in Japan: 9-14 USD/kg in 2004

Life cycle • After hatching • 6 nauplius stages • Attracted to light, feeds on yolk • 3 zoea stages • 3 mysis stages • Postlarvae are carried to the protection of estuaries • Development through larval stages takes ~3 weeks • Juveniles and adults migrate offshore and mature in the ocean • Also spawn offshore • Females grow faster and larger

Reproduction in captivity • Many hatcheries collect gravid females from the sea to spawn in captivity • No control of genetics, disease tolerance • Captive maturation can be done • Large tank at low density: 5-7 shrimp per meter • Constant conditions- temp, pH, light, good nutrition- are important for maturation • Eyestalk ablation in females • After spawning, the female releases eggs into the water, fertilizing them by simultaneously rupturing the spermatophore • 150,000-200,000 eggs per spawn (P. vannamei) • 500,000-750,000 eggs/spawn (P. monodon)

Production methods • Hatcheries • Eggs hatch within 24 hours • After hatching, nauplii are stocked into V or U-shaped tanks • ~3 weeks to reach postlarval stage • Nurseries • Smaller ponds or intensive raceways act as an intermediate between hatchery and grow-out size • Not always used • Most US prawn farms are semi-intensive or intensive ponds • Must make up for land costs, short growing season • Extensive ponds common in South/Central America, where land is cheaper • Ponds stocked in April/May • Stocked at post-larval stage, <1/2 inch

Harvest • Harvest in October when temps drop and growth slow • Potentially 3 crops per year in a warm climate- not in US • Drains are invaluable in shrimp ponds • Gently sloping ponds with drains allow shrimp to concentrate in a catchbasin

Feeding • Ponds are fertilized prior to stocking • Stimulates phytoplankton and zooplankton production • Artificial supplemental food still necessary • Lower protein needed for P. vannamei: 18-35% • 36-42% for P. monodon, more carnivorous • Protozoea can be fed diatoms • Mysid stages can be fed Artemianauplii • Broodstock fed squid, mussels, and cockles

Water Chemistry Parameters • pH 7-9 • DO 5-15 ppm • Temperature 26-29 ˚C • 5-35 ppt salinity • 100-500 ppm hardness (Ca2+ concentration) • Lower may reduce calcified shell • Higher may produce encrustations on the shells • Hardness increased by addition of calcium in the form of agricultural gypsum

Marine Shrimp Aquaculture Advantages Disadvantages • Very popular food item in the US, Japan, and increasingly in EU • Fast-growing (~6 months) • FCR 2:1 or lower • Some natural food supplied • Disease-resistant strains are being produced • Pond must be near brackish water source • Mangrove ecosystems used in pond construction (improving) • Few hatcheries produce post-larval shrimp • Must have pristine water quality • Higher densities usually required to make a profit, increases risk

Thank you!

Shrimp in Aquaculture