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Shrimp/Prawn culture. Penaied shrimp 3 common species (early on) White, pink, and brown shrimp Asian species ( Penaeus monodon ) – most widely cultured in Asia Spawning – important for culture Collecting/sourcing females with spermatophores attached
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Shrimp/Prawn culture • Penaied shrimp • 3 common species (early on) • White, pink, and brown shrimp • Asian species (Penaeus monodon) – most widely cultured in Asia • Spawning – important for culture • Collecting/sourcing females with spermatophores attached • Trawling in short tows to find subject females • Placed in buckets and will spawn w/in 24 hrs • Prevents production of a gonadal development inhibiting hormone
Shrimp/Prawn culture • Spawning (continued) • Alternate methods from ablation • Many studies – not highly successful • Larval stages • 5 naupliar (nonfeeding) stages • 3 protozoea stages (begin feeding at 2nd stage) • 3 mysis stages • Feeding • Larval stages - Phytoplankton, phyto + brine shrimp nauplii or zooplankton (mysis stage) • Postlarval stages –
Crawfish culture • Species/region • Louisiana (80%), Texas, South Carolina • Red swamp crawfish (Procambarus clarkii) • White river crawfish (P. acutus) • 60% from capture fishery (as of early 90’s) • Aquaculture production • SC – 500 – 800 kg/ha/yr • LA – 2000 kg/ha/yr • Spawning (under natural conditions) • Drain ponds w/in few weeks • Animals burrow into pond bottom • Reproduction occurs in burrows • 200 – 700 juveniles per female
Crawfish culture • Feeding/care • Pond flooding in Sept – Oct period (time of hatching) • Vegetation planted in summer as forage • Polyculture with marketable grains (rice, soybeans, etc). • Crop harvested and stubble left for forage • Young crawfish become free swimming (1cm) • Poor growth • Females may leave and find water (undesirable) • Harvesting
Oyster culture • US culture • Atlantic and Gulf of Mexico – American oyster (C. virginica) • Disease problems severely affected wild stocks (Chesapeke bay and Florida Gulf coast) • Methods • Early efforts - • Spat (larvae) settle and grow • Current hatchery production (commercialization) • Spat culture
Oyster culture • Spawning • Oysters conditioned to spawn • Sperm suspension introduced • Female may release several million eggs • Eggs removed with fine mesh sieve • Transferred to filtered seawater • Hatch to larvae within 48 hrs • Metamorphosis occurs (10 days) • Spat stocked at 10 to 50 per oyster shell cultch • On substrate • In bags
Oyster culture • Commercialization • In Washington • Spat produced in hatchery • Feeding • Phytoplankton (feed spat) • Culture algae in fiberglass tanks (10,000 L) • Centrifuge algae down to 1 L • Small amount added to tank • Food for spat and newly settled oysters • Used until seeded cultch distributed to natural environment • Harvest at various sizes