Presentation by Karen Jensen Marine Aquaculture 2013

Common Saltwater Species  Family Penaeidae Whiteleg shrimp Penaeus vannamei Giant tiger prawn Penaeus monodon

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  Penaeus vannamei aquaculture has boomed in recent years  2011: 2,877,542 tons produced  Market price decreasing, USD/kg in 2005  Main suppliers to US: Thailand, Ecuador, India, China, Vietnam  Penaeus monodon  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 eggs per spawn (P. vannamei) 500, ,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 Artemia nauplii  Broodstock fed squid, mussels, and cockles

Water Chemistry Parameters  pH 7-9  DO 5-15 ppm  Temperature ˚C  5-35 ppt salinity  ppm hardness (Ca 2+ 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 AdvantagesDisadvantages  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