cape eleuthera institute
Post on 23-Feb-2016
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Bahamas Researching sustainable cobia mariculture from
breeding to market Use artificial mangroves for waste water treatment Grow out in offshore, deep water (40-90 ft deep)
submerged sea stations Capacity of 120 tons a year
http://www.youtube.com/watch?v=ZZr246dBTAo
Cape Eleuthera Institute
Aquaculture of CobiaRachycentron canadum
Cobia are Awesome!
Sport fishing“Aquapod” Offshore environmentally friendly
containment
Grow to 78 inches long and 135 pounds Strong pelagic swimmers Strong fighters and are “Sport fish” Very fast growing in comparison to other fin
fish Meat has great texture, few bones, and
great taste
Impressive Statistics
Big Fish
Raised for food! Gaining economic importance in Southeast
Asia and China Good tasting/texture flesh and fast growth
make it a potentially good species for mariculture
Has potential to outrun salmon in commercial success.
Grows faster than salmon
Economic Importance
Yum!
Top five producers◦ Taiwan◦ Pakistan◦ Philippines◦ Brazil◦ United Arab Emirates
Countries looking into culture due to economic value◦ U.S.A.◦ China◦ Taiwan
Countries of Importance
In Taiwan ◦ Produce 13-17lb market size fish (export to Japan)◦ Produce 17-22lb fish for domestic consumption◦ Sells for about $2.50 per lb.◦ Costs about $1.10 per lb. to culture◦ Produced more than 5000 tons in 2004
In Puerto Rico◦ $3-$4 per lb. ◦ Shipped to Miami
In China ◦ About $2-$3 per lb. (~$45 for 17lb fish)
Market price is higher than most other finfish
Natural Range of Cobia
Spawn in aggregations, release many small planktonic eggs
Eggs hatch 24-36 hours after fertilization Planktonic larvae 2.5 mm long After five days develop eyes and mouth,
begin feeding At 30 days look like small adult Sexually mature at 2-3 years Live to about 12 years (135#)
Life Cycle
Larval and Juvenile Cobia
Larvae at 12 days oldA. Late larval stage >6 daysB. Juvenile >30 days
Brood stock are kept in tanks or ponds◦ Larvae can also be purchased for culture
They are triggered to breed with ◦ Natural water temperature changes◦ Hormonal additions to the water
Eggs are hatched out in recirculation tanks◦ They float and are just scooped out of the water
larvae are fed started about 3 days after hatching
Reproduction in Captivity
Breeding Stock
Recirculation Systems used for Hatchery and Nursery
Also Green water ponds◦ Fed rotifers at 3 days◦ Microalgae and Artemia nauplii at 7 days
High density larval rearing can give low survival rate ◦ Lowering the density can raise the survival rate
The larvae are size graded at least 3 times before grow out to reduce cannibalism
Production Methods for Hatchery
Incubation and Hatching Tank
• 2000L cone shaped tank• Flow through system• 20L/min flow speed
Open net cage method◦ Used in most places it is cultured
Offshore technology being developed◦ In the US and Bahamas
Recirculation systems ◦ Suitable and in development
Ponds◦ Used in some countries
Production Methods for Grow Out
Ready for Grow Out
Recirculation Systems for eggs and larvae◦ Target temperature range 28-29C◦ Optimal salinity 25ppt (not to exceed 35ppt)◦ pH close to 8◦ High levels of aeration◦ D.O. 8-9 mg/L
Grow out systems need similar conditions to warm tropical and subtropical waters◦ Temperature is most important◦ Must be done in warm areas
Water Chemistry
Larvae eat very small planktonic organisms Adult fish are carnivorous
◦ Crabs, Squids, Shrimp, Fish In captivity are generally fed commercial
fish meal◦ Other options are being studied
Feeds and Feeding
Advantages Disadvantages Very fast growing Good economic
investment (good return) Great tasting and popular
meat Fare well in cultured
environments May keep wild populations
safer if meat available from culture
Ongoing research to address problems
“up and coming” species
Some problems with juvenile survival rates in intensive systems and transportation
Carnivorous diet hard to replicate without fish meal which has environmental concerns
Cage systems have same environmental concerns as salmon and other large cages fishes
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