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Tilapia And Cobia Culture Trong And Son


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Tilapia And Cobia Culture Trong And Son

  1. 1. Technique for Tilapia Culture Trịnh Quốc Trọng [email_address] National Breeding Centre for Southern Freshwater Aquaculture
  2. 2. Outline <ul><li>Introduction </li></ul><ul><li>Biology of Tilapia </li></ul><ul><li>Culture systems </li></ul><ul><li>Techniques for cage culture: </li></ul><ul><ul><li>site selection </li></ul></ul><ul><ul><li>engineering </li></ul></ul><ul><ul><li>Seed: seed quality, stocking density, size at stocking </li></ul></ul><ul><ul><li>fish health management </li></ul></ul><ul><ul><li>feed management </li></ul></ul><ul><ul><li>harvest (size, method, post-harvest) </li></ul></ul>
  3. 3. Introduction <ul><li>Tilapia: common name of a group consists of >80 species </li></ul><ul><li>Three main generas: </li></ul><ul><ul><li>Oreochromis : maternal mouth-brooders </li></ul></ul><ul><ul><li>Sarotherodon : paternal or biparental mouth-brooders </li></ul></ul><ul><ul><li>Tilapia : substrate spawners </li></ul></ul><ul><li>Among the first fish cultured (Masser, 1999) </li></ul><ul><li>Most popular cultured species: </li></ul><ul><ul><li>Nile Tilapia ( Oreochromis niloticus ) </li></ul></ul><ul><ul><li>Lesser extent: red Tilapia ( O . spp) </li></ul></ul><ul><ul><li>Blue Tilapia ( O. aureus ) </li></ul></ul>
  4. 4. Nile Tilapia ( Oreochromis niloticus ) Red Tilapia ( Oreochromis spp.)
  5. 5. <ul><li>Tilapia aquaculture production and value (FishStat Plus v.2.32) </li></ul>
  6. 6. The players (2007) Top 10 Countries Production (tons) 10 Colombia 27960 9 Honduras 28,356 8 Malaysia 32258 7 Taiwan Province of China 76,087 6 Brazil 95,091 5 Thailand 190258 4 Philippines 241183 3 Indonesia 248305 2 Egypt 265,862 1 China, Hong Kong SAR ( S pecial A administrative R egion) 1134080
  7. 7. A little comparison <ul><li>Tilapia worldwide </li></ul><ul><li>2.5 million tones (2007) </li></ul><ul><li>> US$ 3 billions </li></ul><ul><li>Tra catfish in Vietnam </li></ul><ul><li>1.5 million tones (2009) </li></ul><ul><li>US$ 1.5 billions </li></ul>
  8. 8. Tilapia culture in Southeast Asia Countries Culture system Culture model Indonesia Integrated – freshwater Extensive Malaysia Tanks, cages Intensive Myanmar Mono – ponds, tanks Extensive Singapore Mono – cages (brackish) Intensive Taiwan Mono – tanks Intensive Thailand Mono – integrated, freshwater Intensive Vietnam Integrated – VAC Mono – cages, net pens, ponds Semi- to intensive
  9. 9. Biology <ul><li>Temperature: 25 - 35  C </li></ul><ul><li>Dissolved oxygen: as low as 0.5 mg/l </li></ul><ul><li>Salinity: </li></ul><ul><ul><li>wide range depends on species </li></ul></ul><ul><ul><li>in general O. mossambicus > O. spp > O. niloticus </li></ul></ul><ul><li>Protein: </li></ul><ul><ul><li>Juveniles: 30 – 40% </li></ul></ul><ul><ul><li>Adult: 20 – 30% </li></ul></ul><ul><ul><li>Broodstock : 35 – 45% </li></ul></ul>
  10. 10. Culture systems <ul><li>Semi-intensive culture: </li></ul><ul><ul><li>Mono culture </li></ul></ul><ul><ul><li>Mixed- or poly-culture (e.g. with other fish or with Macrobrachium rosenbergii ) in ponds </li></ul></ul><ul><ul><li>Integrated culture (fish cum duck/chicken/pig, VAC, rice-fish, etc.) in ponds </li></ul></ul><ul><li>Intensive culture: </li></ul><ul><ul><li>Cages </li></ul></ul><ul><ul><li>Net pens </li></ul></ul><ul><ul><li>Tanks and race-way </li></ul></ul><ul><ul><li>Re-circulation system </li></ul></ul>
  11. 11. Semi-intensive culture <ul><li>Usually in ponds </li></ul><ul><li>Low input: </li></ul><ul><ul><li>Pond fertilisation (organic and inorganic) </li></ul></ul><ul><ul><li>Fertilisation & feed supplement </li></ul></ul><ul><ul><li>Crop residuals </li></ul></ul><ul><li>Might integrated with husbandry, crop, or other cultured species </li></ul><ul><ul><li>Carp </li></ul></ul><ul><ul><li>Mullets </li></ul></ul><ul><ul><li>Catfsih </li></ul></ul><ul><ul><li>Prawns or shrimps </li></ul></ul><ul><li>Periphyton-based culture </li></ul>
  12. 12. Semi-intensive culture (cont.) <ul><li>Yield: varies </li></ul>
  13. 17. Intensive culture <ul><li>High density  max yield, less water </li></ul><ul><li>High input </li></ul><ul><li>Ponds or cages </li></ul>
  14. 18. Intensive culture in ponds <ul><li>Water quality: </li></ul><ul><ul><li>DO </li></ul></ul><ul><ul><li>Temp </li></ul></ul><ul><ul><li>Salinity </li></ul></ul><ul><ul><li>Ammonia </li></ul></ul><ul><ul><li>pH </li></ul></ul><ul><li> water exchange and engineering (paddle wheels, aeration) are essential </li></ul><ul><li>Nutrition and feeding </li></ul><ul><li>Stocking density </li></ul>
  15. 19. Intensive culture in ponds <ul><li>Density: 30,000; 59,000; 122,000 fish/ha </li></ul><ul><li>Unaerated pond: 8,4 (density 59,000/ha) – 11,0 (122,000) tonnes/ha </li></ul><ul><li>Aerated pond: 6.3 (density 30,000/ha) – 20.5 (111) t/ha </li></ul>
  16. 20. Yield: 25 tonnes/8,000 m 2 (31.25 tonnes/ha)
  17. 21. Intensive culture indoor <ul><li>Developed countries </li></ul><ul><li>Recycling system </li></ul><ul><ul><li>Tanks </li></ul></ul><ul><ul><li>Raceways </li></ul></ul><ul><ul><li>Heated water </li></ul></ul><ul><ul><li>Addition of oxygen </li></ul></ul><ul><li>Completely use of pelleted feed </li></ul>
  18. 22. Intensive culture indoor
  19. 23. Intensive, recycling system outdoor <ul><li>Israel or Taiwan </li></ul><ul><li>Lined, circular ponds </li></ul><ul><li>Completely or partially recycle of water </li></ul>Intensive pond, Bet Shean Valley, Israel Intensive pond, Central Israel
  20. 24. Intensive fish pond, Jordan Valley, Israel
  21. 25. Intensive fish pond, Northern Coastal region, Israel
  22. 26. Cage culture <ul><li>Popular in Asia </li></ul><ul><li>Most single important, popular Tilapia culture in the Mekong Delta of Vietnam </li></ul><ul><li>Case size and type </li></ul><ul><li>High stocking density </li></ul><ul><li>Pelleted feed </li></ul>
  23. 27. Advantages and limitations of cage culture <ul><li>Advantages </li></ul><ul><li>Relatively low investment </li></ul><ul><li>High production, faster growth </li></ul><ul><li>Easy observation and management </li></ul><ul><li>Treatment of disease </li></ul><ul><li>Movement and re-location </li></ul><ul><li>Use available water resources </li></ul><ul><li>Easy harvest </li></ul><ul><li>Optimum use of feed </li></ul><ul><li>High stocking density </li></ul><ul><li>Reduce pressure on land </li></ul><ul><li>Control reproduction </li></ul><ul><li>Control predator and competitors </li></ul><ul><li>Limitations </li></ul><ul><li>Risk of theft </li></ul><ul><li>Risk of fish lost </li></ul><ul><li>Diseases outbreak and control </li></ul><ul><li>Low tolerance to poor water quality </li></ul><ul><li>Difficult to apply in rough weather </li></ul><ul><li>Water exchange is essential </li></ul><ul><li>Rapid fouling </li></ul><ul><li>Feed lost </li></ul><ul><li>Environmental impacts (feed lost, fish waste) </li></ul>
  24. 28. Cage culture: Site selection <ul><li>Good water quality: </li></ul><ul><ul><li>No acidity </li></ul></ul><ul><ul><li>No fluctuation </li></ul></ul><ul><ul><li>pH 6.5 – 8.5 </li></ul></ul><ul><ul><li>DO > 5 mg/l </li></ul></ul><ul><ul><li>COD 10 mg/l </li></ul></ul><ul><li>Straight and constant current (0.2 – 0.5 m/s) </li></ul><ul><li>Does not obstruct navigation </li></ul><ul><li>Far from discharges water of industry and cultivation </li></ul><ul><li>Avoid: deep current, turbidity, aquatic plants, </li></ul><ul><li>Close to transportation (feed, materials, fish, etc.) </li></ul>
  25. 29. Engineering <ul><li>Rectangle is most popular </li></ul><ul><li>Material: </li></ul><ul><ul><li>ease of construction, disinfection, no side-effect to fish </li></ul></ul><ul><ul><li>wooden, fiberglass, metallic frame </li></ul></ul><ul><ul><li>stainless steel net </li></ul></ul><ul><ul><li>bouy: plastic or metallic containers </li></ul></ul><ul><li>Size: </li></ul><ul><ul><li>Small: 3  5  3 m </li></ul></ul><ul><ul><li>Medium: 5  10  4 m </li></ul></ul><ul><li>House on top, fish compartment submerged </li></ul>
  26. 31. Cages of various size and constructions
  27. 32. Net pens
  28. 33. Feeding in a cage
  29. 34. Tilapia culture in the Mekong Delta of Vietnam <ul><li>Seed: Selective breeding programs </li></ul><ul><li>GIFT </li></ul><ul><ul><li>GIFT generation 10 th from WFC </li></ul></ul><ul><ul><li>Two generation selected in Vietnam </li></ul></ul><ul><li>Red Tilapia: </li></ul><ul><ul><li>Base population from Ecuador </li></ul></ul><ul><ul><li>First generation produced in Vietnam </li></ul></ul>
  30. 35. Cage culture in the Mekong Delta of Vietnam Cage size 5  10  4 m Stocking density (pcs/m 3 ) 100 – 120 Period All year round Size at stocking 20 – 100 pcs/kg Culture period 4 – 6 months Harvest size 500 – 700 Pelleted size (mm) 1.5, 2.0, 3.5, 5.0 Crude protein content (%) 35, 30, 28, 25 Feeding time (per day) 2 – 3 Cage cleaning and (parasite) disinfection Once/week Logging Daily Daily monitoring Yes
  31. 36. Harvest <ul><li>Netting </li></ul><ul><li>Domestic market: </li></ul><ul><ul><li>Live-well boat or truck </li></ul></ul><ul><li>Processing plants (export) </li></ul><ul><ul><li>Ice-killing </li></ul></ul><ul><ul><li>Boats or trucks </li></ul></ul>
  32. 37. Cage culture in the Mekong Delta of Vietnam Culture period (days) Offspring of GIFT 11 th generation Existing Nile Tilapia strain Cage 1 (2009) Cage 2 (2009) 2008 – 2009 BW (g) Daily growth (g/day) BW (g) Daily growth (g/day) BW (g) Daily growth (g/day) 0 12.5 12.5 12.5 30 60.0 1.6 60.0 1.6 40.0 0.9 45 125.0 4.3 125.0 4.3 60.0 1.3 60 200.0 5.0 200.0 5.0 90.0 2.0 75 265.0 4.3 265.0 4.3 125.0 2.3 90 340.0 5.0 340.0 5.0 170.0 3.0 105 420.0 5.3 420.0 5.3 220.0 3.3 120 521.0 6.7 521.0 6.7 280.0 3.6 150 677.0 5.2 631.0 5.0 400.0 4.0 180 832.0 5.1 - - 500.0 3.3
  33. 38.
  34. 39. References <ul><li>El-Sayed, A-F. M., 2006. Tilapia culture . CABI Publishing, 277 pp. </li></ul><ul><li>Beveridge, M. C. M., and McAndrew, B. J., 2000. Tilapias: Biology and Exploitation , Fish and Fisheries Series 25, Kluwer Academic Publishers, the Netherlands, pp. 505. </li></ul><ul><li>Teaching materials from Dr. Phạm Văn Khánh, National Breeding Centre for Southern Freshwater Aquaculture. </li></ul>
  35. 40. MSc. Vo Minh Son Email: [email_address] Division of Experimental Biology, Research Institute for Aquaculture No.2 3 - 2010 TECHNIQUES ON COBIA CULTURE
  36. 41. PART II COBIA ( Rachycentron canadum ) CULTURE
  37. 42. <ul><li>1. Introduction </li></ul><ul><li>2. Biology characteristics </li></ul><ul><li>3. Farming system </li></ul><ul><li>4. Techniques for cage culture </li></ul><ul><ul><li>Site selection </li></ul></ul><ul><ul><li>System design </li></ul></ul><ul><ul><li>Cage preparation </li></ul></ul><ul><ul><li>Seed management </li></ul></ul><ul><ul><li>Feed management </li></ul></ul><ul><ul><li>Health management </li></ul></ul><ul><ul><li>Harvesting </li></ul></ul><ul><li>5. Common diseases in Cobia </li></ul><ul><li>6. Economic analysis </li></ul>OUTLINE
  38. 43. 1. INTRODUCTION <ul><li>The status of cobia culture </li></ul><ul><li>Attractive candidate for mariculture due to its rapid growth and succulent flesh. </li></ul><ul><li>Global aquaculture production of cobia has been increasing rapidly, up to 3000-fold over a 10-year period (1997-2007), while captures have remained stable around 10,000 tons . </li></ul><ul><li>Cobia have been cultured in Taiwan in 1990s, while US have been succeeded in spawning by using hormone injection. </li></ul><ul><li>Recently research and production has been considered or initiated in the EU, Brazil, and Panama. </li></ul><ul><li>Exporting market: Japan , China </li></ul>
  39. 44. Fig. 1. Global cobia aquaculture production and value (1995-2007) (FAO, 2007)
  40. 45. Fig. 2. Cobia aquaculture compared to another marine fish in 2007 31,359 tons 75,406 tons 1,744,700 tons (FAO, 2007)
  41. 46. Table 1. Cobia aquaculture production of some countries in 2007 Countries Cobia production (tons) China 25,855 Taiwan 3,998 Vietnam 1,500
  42. 47. <ul><li>In Vietnam, cobia reproduction commenced in 1998 and the first commercial seed production were obtained in 2002 </li></ul><ul><li>The techniques including broodstock management, larval rearing, fry transportation and cage culture have been improved. </li></ul><ul><li>Cobia production estimated about 1500MT in 2008, the third largest producer of farmed cobia in the world, after China and Taiwan. </li></ul><ul><li>Grow-out production of cobia were cultured in both small scale wooden raft cages and in high density polyethylene circular floating net cages. </li></ul>
  43. 48. <ul><li>North part: from Vinh Ha Long Bay and Bai Tu Long bay in the north. </li></ul><ul><li>North central part: Nghe An </li></ul><ul><li>Central part: Van Phong bay, Khanh Hòa Province </li></ul><ul><li>South of VN: Ba Ria- Vung Tau; Kieng Giang </li></ul>Cobia culture zone in Vietnam
  44. 49. 2. BIOLOGY CHARACTERISTICS <ul><li>Division: Chordata </li></ul><ul><ul><li>Class: Pisces </li></ul></ul><ul><ul><ul><li>Order: Perciformes </li></ul></ul></ul><ul><ul><ul><ul><li>Family: Rachycentridae </li></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>Genus: Rachycentron </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>Species: R. canadum (Linnaeus, 1766) </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>Common name: Cobia, black kingfish, black salmon, cabio, crabeater, cubbyyew, kingfish, lemonfish, ling,prodigal son, runner. </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>Vietnamese name: Cá Bớp, Cá giò </li></ul></ul></ul></ul></ul>
  45. 50. <ul><li>Size/weight/age </li></ul><ul><li>Max length: 200 cm TL male/unsexed; common length: 110 cm TL male/unsexed; max. published weight: 68.0 kg; max. reported age: 15 years. </li></ul><ul><li>Environment </li></ul><ul><li>- Reef-associated; brackish; marine; depth range 0 - 1200 m </li></ul><ul><li>Distribution </li></ul><ul><li>- Worldwide in tropical and subtropical waters. </li></ul><ul><li>Western Atlantic: Canada to Bermuda and Massachusetts, USA to Argentina, including the Gulf of Mexico and entire Caribbean. </li></ul><ul><li>Eastern Atlantic: Morocco to South Africa. </li></ul><ul><li>Indo-West Pacific: East Africa and Hokkaido, Japan to Australia </li></ul>
  46. 51. <ul><li>Biology </li></ul><ul><li>- Habitats: mud, sand and gravel bottoms; over coral reefs, off rocky shores and in mangrove sloughs; inshore around pilings and buoys, and offshore around drifting and stationary objects; occasionally in estuaries. </li></ul><ul><li>- Feed on crabs, fishes, and squids </li></ul>
  47. 52. Fig. 3. Gain weight of cobia cage culture in Vietnam Initial weight: 10-15g/fish Harvest size: 6-6,5kg Culture period: 18 months Feed: trashfish FCR: 7-8
  48. 53. Concrete pond or Bricky pond (hard sides, soft bottoms with mud, sands, or mixed matters; 1,5-3 m depth) Earthen pond with aeration system 3. FARMING SYSTEM
  49. 54. Tank culture for cobia Floating net cage culture
  50. 55. In Taiwan, the cobia is commonly cultured in either ponds or marine cages: <ul><li>Pond Culture: </li></ul><ul><li>Muddy bottoms </li></ul><ul><li>Depth: 1.5 to 3 m </li></ul><ul><li>Feed: formula feed </li></ul><ul><li>Stocking Density: 1-1,5 fish/m 2 </li></ul><ul><li>Good aeration facilities installed in the pond. </li></ul><ul><li>Feeding: 2 times/day, </li></ul><ul><li>To compare it with pond culture, the cage culture requires more in capital and technology. Its practice is risky but highly profitable. </li></ul>
  52. 57. Fig. 4. Family-owned cobia cage farm in Taiwan. Fig. 5. Commercial cobia cage farm in Taiwan.
  53. 58. Rearing tank (10m 3 ) (5g/fish) Nursery in cage or ponds (2000m 2 ) (30-50g/fish) Cage culture (6x6x3m) (100-500g/fish) Polyethylene circular floating net cages (12x4m) (>6kg/fish) 15-18 months Fig. 6. Cobia culture operation in floating cage in Vietnam Wood cage culture (6x6x3m) (> 6000g/fish) 15-18 months
  54. 59. Key points of successful floating net cage <ul><li>Set the facilities in a suitable site. </li></ul><ul><li>Procure health juveniles as seed </li></ul><ul><li>Feed the fish with good quality food </li></ul><ul><li>Control parasitic and bacterial diseases </li></ul>Several problems in Floating Net Cages <ul><li>Slow growth </li></ul><ul><li>Low survival rate </li></ul>
  55. 60. a. Site Location Good site (If strong wind only slow wave) <ul><li>A calm inlet or bay with sandy or rocky bottoms with slow wave </li></ul><ul><li>2. Water depth is between 10-30 m in the high tide or low tide. </li></ul><ul><li>3. Current velocity between 10-30 cm/s. </li></ul><ul><li>4. Transparency more than 5 m. </li></ul><ul><li>5. Distance from possible source of water pollution </li></ul><ul><li>6. Have a source of feed every time </li></ul><ul><li>7. Infrastructure must be present </li></ul><ul><li>Suitable site selection implies successful mariculture in future </li></ul>Bad site (Strong Wave) Bad site (Muddy water in rain season) Bad site (Turbid water)
  56. 61. Site selection <ul><li>Site selection for mariculture involves numerous variables: </li></ul><ul><li>Current pattern; for good water circulation. </li></ul><ul><li>There is buffer zone between raft unit with buffer zone among floating net cages. </li></ul><ul><li>Good lay out for easy work facilitate. </li></ul><ul><li>Attention to hygiene mariculture environment </li></ul><ul><li>Limited number of floating net cages which considering carrying capacity for sustainable aquaculture. </li></ul>
  57. 62. <ul><li>Use only good quality material, available, cheap, and has long-term economic value. </li></ul><ul><li>The size of raft is not too big (10x10 m), so that easy to move if necessary. </li></ul><ul><li>Using anchor and other things that cannot be rusty, with limited number, and placed in certain area that can not harm the environment/coral. </li></ul><ul><li>Buoy can be made from Styrofoam, plastic drum; plastic drum is injected by Styrofoam. </li></ul><ul><li>Design and lay out of floating net cages is made to make easier operational </li></ul>Design and lay out of floating net cages Design and lay out of floating net cages is need to consider several variables : CONDITION IN TANJUNG PUTUS Pond culture Pond Unit lay out not regulated nicely
  58. 63. Cage culture in Vung Tau province, Vietnam Too crowded Inhabitant zone Pond shrimp culture Estuary zone
  59. 64. Culrure area Fishing ship Inhabitant zones Inhabitant zones Nha Trang
  60. 65. Quang Ninh
  61. 66. Phu Qui islands Coral reef Binh Thuan
  62. 67. Khanh Hoa
  63. 68. Buoy (200L) Two bar of wood (0,3m) 6m 6m b. Design of draft of floating net cage 0.5-1m Storehouse Lab Accomod-ation Living room Cleaning area
  64. 69.
  65. 70. Anchor Fig. 7. Cage design for marine fish rearing and growout
  66. 71. Equipment for commercial cage culture Boat using for transportation of feed, trash fish, freshwater, visitors, etc. Electric generator: 10Kwh Water compressor machine (15HP): for spraying and washing nets Air pump: 500W Scale: 1kg, 5kg, 60kg
  67. 72. Net cleaning area Storehouse House for workers Boat Fig. 8. System design for cobia culture in Vung Tau, Vietnam
  68. 73. Fig. 9. Floating net cage for Cobia culture in Vietnam
  69. 74. Floating net cage in Vietnam
  70. 75. Different types of FNC in Indonesia
  71. 76. c. Cage preparation Cage size: 3x3x3m, 4,5x4,5x4,5, 6x3x3m, 6x6x3m, 12x6x4m depending fish size Net size: PE 380D/15, 380D/18, 380D/21, mesh size (2a = 0,5-10cm), net weight (15-23kg)
  72. 77. Table 2. Mesh size of nets according to fish size (In Vietnam) Fish weight (g) Cage size (m) Mesh size (cm) < 50 2 x 2 x 2 0.5 50-500 3 x 3 x 3 1-2 500-2000 4 x 4 x 3 2-3 2000-4000 6x6x3 4-5 4000-6000 12x6x4 5-7 > 6000 12x6x4 7-10
  73. 78. Select good quality of the seeds for culture stock <ul><li>Free from disease (VNN virus, bacteria, and protozoa) </li></ul><ul><li>Stocking size: 50-500 g/fish </li></ul><ul><li>Normal body (not deformity) </li></ul>Juvenile of humpback grouper infection by VNN Juvenile of tiger grouper infection by Protozoa d. Seed management
  74. 79. Key seed transportation to success 1. Size of Seed 9-12 cm TL 2. To enrich feed with Vit-C, before transportation 3. Stop feeding 1-2 day before transported 4. Estimation of stocking density 5. Temperature 22-25 ºC
  75. 80. Table 3. Size and density of fish for transportation Fish size (cm) Density (fish/L) Groupers Cobia 4-6 7-8 9-12 12-15 20-30 10-15 - - - - 10-15 7-10
  76. 81. + Transportation with plastic bag (close system) - Water :Oxygen 1:2 or 1:3 - By plane or car 6-24 hour, survival rate: 95-98% Seed transportation
  77. 82. + Seed Transportation with Tank or boat and Aeration (open system) - Temp. : 22-24oC - Transporting by car or boat (<12 hours) - Survival rate: 95-100%
  78. 83. Table 4. Fish size and stock density in FNC Fish size (g/fish) Stock density (fish/m 3 ) < 50 50-500 500-2.000 2.000-4.000 4.000-6.000 > 6.000 30 18 14 8 5 4
  79. 84. e. Feeding management <ul><li>Trash fish </li></ul><ul><li>Formulated feed </li></ul><ul><ul><li>Moist feed </li></ul></ul><ul><ul><li>Commercial feed </li></ul></ul>Trashfish Dry pellets
  80. 85. Table 5. Body weight and feeding rate of fish fed trash fish and artificial feed Fish size (g/fish) No. of feeding times (time/day) Feeding rate (%) (trash fish) Feeding rate (%) (Pellet feeds) < 50 50-200 300-1.000 1.000-3.000 >3.000 5 4 3 2 1 17 13 9 7 5 5 2-3 0,5-0,7
  81. 86. Buying trash fish from fisherman Frozen trashfish Preparation trash fish
  82. 87. Problems related to using trash fish <ul><li>Trash feed is very short storage life. </li></ul><ul><li>The nutritional quality of trash fish will decline within a few week. </li></ul><ul><li>Trash fish supply is not stable, dependent to season. </li></ul><ul><li>Trash fish readily break up into small pieces when eaten, around 30-50% of trash fish can be lost during the feeding process. </li></ul><ul><li>Feeding losses from trash fish are 2 to 4 times higher than for pelleted feeds. </li></ul><ul><li>Localized pollution and water quality degradation. </li></ul><ul><li>Transmission of parasites and diseases. </li></ul>
  83. 88. New and better practises – use of formulated feed Formulated feeds are of two types: 1. ‘Moist’ feeds, that can be produced on the farm; and 2. Commercially produced pellets that must be purchased from a feed manufacturer
  84. 89. Benefits of using formulated feed <ul><li>Economic advantages </li></ul><ul><li>Fish grow faster and are healthier in comparison to fish fed trash fish. </li></ul><ul><li>The FCR for cobia conditioned to eating formulated dry pelleted feed should be less than 2:1, comparison with the fish fed trash fish, the FCR is 6:1 or higher. </li></ul><ul><li>Environmental benefits </li></ul><ul><li>Less pollution, stable water quality, reducing disease problems. </li></ul>
  85. 90. Protein requirement of groupers and cobia Protein requirement of grouper species (%) Cromileptes altivelis 54.2 Epinephelus akaara 49.5 Epinephelus areolatus 60 Epinephelus malabaricus 50.2 Epinephelus malabaricus 47.8 Epinephelus striatus > 55 Epinephelus coioides 43 Epinephelus salmoides 50 Cobia 42-45
  86. 91. f. Fish Health Management in FNC Water quality requirement <ul><li>pH : 7,5-8,5 </li></ul><ul><li>Temperature : 26,0-30,0 o C </li></ul><ul><li>Salinity : 22,0-34,0 ppt </li></ul><ul><li>Dissolve Oxygen (DO) : 4,0-8,0 ppm </li></ul><ul><li>Nitrite NO 2 N : 0,0-0,05 ppm </li></ul><ul><li>Ammonia (NH 3 ) : <0,02 ppm </li></ul>
  87. 92. Net maintenance Change of the net Drying Cleaning the net Grading of fish Grading Grading Grading
  88. 93. Disease prevention Dipping in fresh water about 5-15 minutes every month for treatment of parasites ( Benedenia sp) Dipping with formalin 30 – 60 ppm about 3-5 ours for treatment protozoa
  89. 94. Medical treatment Mixed antibiotic in pellet Mixed vitamin c in dry pellet with sprayer Mixed vit mix in trash fish Mixed antibiotic Mixed in moist pellet Mixed vit c and egg in pellet
  90. 95. 5. Common diseases and treatment method
  91. 96. 1. Clinical signs of vibriosis <ul><li>Lost of appetite </li></ul><ul><li>Darkening of body coloration </li></ul><ul><li>Hemorrhagic septicemia (blood poisoning) </li></ul><ul><li>Ulcerative lesions on the skin </li></ul><ul><li>Necrotic fins </li></ul><ul><li>Eye opacity </li></ul><ul><li>Exophthalmia </li></ul><ul><li>Pale gills </li></ul><ul><li>Red spots in tanks (in hatchery) </li></ul>A. Bacteria
  92. 97. Prevention and control of vibriosis: <ul><li>Maintain of good water quality </li></ul><ul><li>Good husbandry procedures </li></ul><ul><li>Lower stocking densities </li></ul><ul><li>Administration of antibiotics </li></ul><ul><li>Vaccination/Immunoprophylaxis </li></ul>
  93. 98. 2. A gram-negative rods infection <ul><li>Species infected: Rachycentron canadum , Lates calcarifer </li></ul><ul><li>Clinical signs: </li></ul><ul><li>Swollen abdomen </li></ul><ul><li>Sluggish swimming near the water surface </li></ul><ul><li>Resting on the tank bottom </li></ul><ul><li>Tubercle in the liver with numerous </li></ul><ul><li>Rod-shaped bacteria. </li></ul><ul><li>Causative agent </li></ul><ul><li>Possibly Pasteurella piscicida (Photobacterium damsela ), the causative agent of bacterial pseudotuberculosis in marine fish. </li></ul>
  94. 99. Prevention and Control <ul><li>The bacteria have not been succesfully isolated yet, the most appropriate antibiotic cannot be chosen. </li></ul><ul><li>Prefuran (a wide antibacterial spectrum) may be useful. </li></ul><ul><li>Oxolinic acid is effective to reduce the mortality due to Pasteurella infection in sea bream juvenile. </li></ul>
  95. 100. A. Parasites 1. Trichodina infection <ul><li>Clinical signs </li></ul><ul><li>Usually not visible when fish are only slightly infected </li></ul><ul><li>Excess mucus production on the gills and body surface due to irritation caused by the cilia and hooks of the parasites </li></ul><ul><li>Microscopic observation of gills filament and mucus taken from the body surface can confirm parasitic infection. </li></ul><ul><li>Causative agents </li></ul><ul><li>Ciliated protozoa, Trichodina spp., cause this disease. The parasite has a saucer-like shape, up to 100  m in diameter, with a fringe of cilia around the perimeter. The parasite locates on the surface of the gills and skin with a spinning motion, which damages the host tissues. </li></ul><ul><li>Treatment </li></ul><ul><li>When a serious infestation occurs, a bath with 25-30 ppm formalin for 1-2 day is recommended to remove the parasites. Infection of this parasite can be prevented by maintaining good conditions in the fish rearing tank. </li></ul>
  96. 101. <ul><li>Causative agents </li></ul><ul><li>Two genera of skin monogenetic trematodes, </li></ul><ul><ul><li>Benedenia </li></ul></ul><ul><ul><li>Neobenedenia , </li></ul></ul><ul><li>Treatment </li></ul><ul><li>Bathing in 5 ppt brackishwater for 15 minutes is recommended for removing the parasites. If the fish has a mechanical injury on the body or eyes, administration of antibiotics is also necessary. </li></ul>2. Benedenia and Neobenedenia
  97. 102. FISH BEHAVIOR VISUAL DIAGNOSE NORMAL ABNORMALITY <ul><li>Haemorage on mouth, scale and fins </li></ul><ul><li>Ulcer </li></ul><ul><li>Less appetite </li></ul><ul><li>Irreguler swimming behavior </li></ul><ul><li>Some mortality </li></ul><ul><ul><li>No appetite </li></ul></ul><ul><ul><li>Weak swimming behavior </li></ul></ul><ul><ul><li>Stay on the bottom </li></ul></ul><ul><ul><li>Dark color and empty stomach </li></ul></ul><ul><ul><li>High mortality </li></ul></ul><ul><ul><li>No appetite </li></ul></ul><ul><ul><li>Slow growth </li></ul></ul><ul><ul><li>Abnormal morfology </li></ul></ul><ul><ul><li>Some mortality </li></ul></ul><ul><ul><li>Pale body color </li></ul></ul><ul><ul><li>Surface swimming </li></ul></ul><ul><ul><li>Stratching on the net </li></ul></ul><ul><ul><li>Less appetite </li></ul></ul><ul><ul><li>Opaque eyes </li></ul></ul><ul><ul><li>Wounded body </li></ul></ul>LABORATORIAL DIAGNOSA PREVENTION / TREATMENT <ul><li>Gram-negatif bacteria </li></ul><ul><ul><li>VIBRIO </li></ul></ul><ul><ul><li>FLEXIBACTER </li></ul></ul>VIRUS Gram- positif bac. STREPTOCCOCUS DIFORMITY/ MALNOURISHED <ul><li>PARASITE </li></ul><ul><ul><li>Benedenia sp </li></ul></ul>Skilled technician Prevention or Treatment Method for Disease and Abnormality at RIM’s FNCs
  98. 103. g. Harvesting and marketing After 15-18 months (10g to 6,500g/fish), fish was harvested for local market or exporting to Japan, China, Taiwan, HongKong. Fish is starved for one day period to harvest Right after harvest, fish was killed , bled and chilled prior to transporting to processing plants. Products: live fish for local market and frozen fillet for exporting Marketing: China, Japan, HongKong
  99. 104. Table 6. Economic analysis for cobia cage culture in Vietnam Order No. Component Parameters Prices (USD) 1usd = 18.000 vnd Total (USD) A Cost 84,366 1 Fingerling size 14-16 cm 2 Culture period 18 months 3 Survival rate 50% 4 No. of fingerling 10,000 fish 0,66 6,600 5 Feed = (50%) x BW (6kg) x FCR = 7 210,000 kg 0.3 63,000 6 Labor cost (15 months) 6 workers 66.6 6,000 7 Equipment maintenance 22 cages 166.6 3,666 8 Freshwater cost, fuel cost 18 months 166.6 3,000 9 Equipment, and disease treatment 18 months 55.5 1,000 10 Other 1,100 B Gross profit 0.3USDx5000fishx6kg/con 105,000 B-A Net profit 20,634
  100. 105. References Liao, I.C., T.-S. Huang, W.-S. Tsai, C.-M. Hsueh, S.-L. Change, E.M. Leano. 2004. Cobia culture in Taiwan: current status and problems. Aquaculture 237 (2004) 155–165. Holt, G.J., C.K. Faulk, M.H. Schwarz. 2007. A review of the larviculture of cobia Rachycentron canadum, a warm water marine fish. Aquaculture 268 (2007) 181–187. Cobia ( Rachicentron canadum ) aquaculture in Vietnam. Recent developments and Prospects. Lavi’09 – Fish and Shelfish Laviculture Symposium. Training course. Dissemination of sustainable mariculture technology. 2005. Research Institute Techniques on cobia culture in Vietnam (Vietnamese language). 1007. Science and Technology Information.
  102. 107. Full name : VO MINH SON Sex : Male Institution : Research Institute For Aquaculture No.2 Address for Correspondence: 116 Nguyen Dinh Chieu, Dist 1, Ho Chi Minh, City Vietnam Office Phone/Fax. : +84-8- 3 8 229592 ; fax 84-8-8226807 Home Phone/Mobile : +84 982949827 E-mail: vominhson @ Field/ Specialization : Aquaculture Experience s : Livefood (algae, rotifer); seed production of grouper, seabass, clam, probiotics and fish immunity .