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Cobia Aquaculture Todd Shomber . Taxonomy Family: Rachycentridae Rachycentron canadum.
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Quick Facts:* Other names: Lemon fish and Ling. * More are caught by Rec Fishers than Commercial boats.Diet: Crabs, Fish, and Squid *Growth up to 72in or 1.82 metersand weight up to 135lbs.*Habitat: All structure types but mainly found around floating objects offshore.
Spawn: April-September in G.O.M about every 10 days Dispense sperm and eggs into water column where fertilization occurs Larvae hatch a 24-36 hours later One month after hatching juvenile has adult coloration Fully mature: males 1-2 years females 2-3 years Life Cycle Life Cycle
Broodstock Cobia produce between 1-1.2 million eggs per spawn
Spawn Stimulation Cobia stimulated to spawn through: Hormones, changing water temp or photoperiod.
Larval Rearing Tank in recirculating raceway system Juvenile Cobia fed enriched rotifers and naupliiJuveniles slowly weaned off zooplankton to dry food after 25-30 days.5-10% of eggs survive this stage
*Juvenile Cobia in raceway systems*Raised in this system to at most 1000 grams*Major goal of this stage is to grow fish large enough to transport to outdoor cages(grow out systems) but small enough to transport in mass numbers with a minimal death rate.
Grow out phase:*Successful in near shore and offshore cages*Largest cages used in Caribbean measured at 3000 m3*Suggested temp to minimize grow out time and reduce disease is 29C* Regular water flow through cages to keep a continuous amount of high DO is necessary *Grow out period is 1-1.5 years/ Final weight at 6-10kg
*Recirculating systems for eggs, larvae, and juveniles • Temperature around 29C • pH around 8 • High aeration levels (open water cages as adults) • D.O. 8-9 mg/L • Salinity best at 25ppt Water Chemistry
Grow out tanks need water similar to that of sub tropical oceans • Temperature is the biggest key • Most be grown in warm areas Water Chem (continued)
Farm Raised Vs Wild Food Rotifers- 8oz 13$ Shrimp- 1oz 13$Marine Pellets- 100g 8$ Blue crab- 1 dozen whole crabs 40$Sustenance
Feed per day* China uses both floating and sinking pellets(42-45% crude protein)* Caribbean uses U.S produced pellets containing (50-53% crude protein)* Fed 6 days a week at 0.5-0.7% body weight.
Market Value *Very Fast Growth Rate. Becomes mature at 1-2 years.*Top country production: China and Taiwan province of China. * Great tasting fish, not many bones. * Has potential to compete with Salmon in production rates and commercial success * Grow faster than Salmon * Raised for consumption.
Market Value continued….* Cobia farming is in its infancy *China and Taiwan Province finding that good quality Cobia have potential to be one of the most important marine fish of the commercial fish future.*Greater market value than other fin fish * Selling to Japan, China, and U.S*Cobia fillets in U.S anywhere from 17-25$/lb.
Economic Future* Improvements to nursery phase of fish will be needed for large farming of Cobia. *U.S and Taiwan working on intensive and super intensive Recirculating Systems* If this can occur………………………………………………………………………………………………………………………………………………………………………………………
Fast Growing (mature in 3 years tops) • Sustain health in cultured environments • May keep wild populations safer • A new “star” in the aquaculture world • Good investment (17-25$ lb) • Great tasting & versatile cooking methods Advantages Hugh’s Favorite!!!!!!!
Problems with juvenile survival rate from egg to larvae form(5-10%) and during transportation to grow out tanks • Hard diet to replicate (shrimp, blue crabs, and squid) • Fickle about their water chemistry (29C, pH 8, and salinity at 25ppt) • Cage systems have environmental concerns (Where does the “duke” go?) • Cobia are very easily infected with a variety of diseases. (Marine velvet disease, Trichodinosis, and Monogenean infestation) Disadvantages
In summary: Cobia can be ,if given the proper amount of attention, a competitor with Salmon on the aquaculture landscape. Research needs to improve in the areas of larval and juvenile growing and survival rates, but the Cobia’s fast growth and high price tag are advantages that are not easily ignored.
Are we sure our teacher isn’t a pro wrestler with the name Hugh Hammer?