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IMPROVEMENT OF LARVAL REARING TECHNIQUE FOR Cromileptes altivelis
Gondol Research Institute for Maricultture Central Research Institute for Aquaculture
Australian Centre for International Agricultural Research(ACIAR)
Improved Hatchery and Grow-out Technology for Grouper Aquaculture in Asia-Pacific Region
Introduction
Improve technology
• Natural seed declining• Survival rate is irregular • High demand (as ornamental & Aq.)• High value (US$:12-78/kg)• Promising for business
Improvement of LavicultureTechnology
Aiming to:• Improve survival rate
• Improve quality of seeds
• Standardize the procedure of larviculture
• Broodstock management• Eggs selection• Larval feeds• Larval rearing • Diseases• Further development
Scope of research
BROODSTOCK MANAGEMENT
Maturation -Outdoor circular tank, 100-t, 2-2.5 m deep-Flow through system, exchange rate 200-400 % -Sex ratio M:F (1:2). Female(1-2.5 kg BW), Male(>2.5 kg BW)-Feed fresh mixed trash fish+squid+1% Vit.mix (1-3 % BW/day)
Spawning:Throughout a year, 3-7 before & after new moon phase
Caution
• Use only floating eggs• Wash eggs with 20 ppm iodine or UV treated water• At water temperature 27-28 oC, eggs hatching 18-20 hrs.• Density eggs for laviculture 5-10 eggs/l
Egg Selection
Larval feed:
-Nannochloropsis-Enriched rotifer -Enriched Artemia-Artificial diet (commercial larval feed)
05
101520253035
Body length (µm)
Freq
uenc
y
90 110100 120 130 140 150 160 170 180
Larval rearing•Tank shape: circular or rectangular • Vol. 10-t, 1.2 m deep• Light blue, yellow color• Roofed or indoor hatchery
Larval Rearing (Cont.)
Days after hatching 0 5 10 15 20 25 30 35 40 45 50------------------------------------------------------------------------------------------Feeding regime: Nannochrolopsis --------------------- SS-rotifer (5-7 ind/ml) --- S-rotifer (8-10 ind/ml) ----------------- Artemia (0.2-0.5 ind/ml) ------------------------------ Artificial diet
ML-200-400 -------------------------ML-400-800 -------------------
Water management: Squid oil ---- Water exchange 10% -----------
20% -------------50% --------
Running water -----------------Siphoning -----------------------------------------------
Feeding & water management schemes
Survival rates• At Research Institute: 23.4-54.9 %• At Commercial Hatcheries (4): 11.3-51.0 %• At Backyard Hatchery (10) : 7.0-35.4 %
Factor contributing larval mortality•Egg quality•Floating death, trapped water surface•Elongated dorsal spine•Nutritional deficiency•Virus VNN
Further development
• Two Government hatcheries• Four commercial hatcheries• More than hundred backyard hatcheriesbeing actively produce the seed.
Aceh
Batam
LampungJepara
Lomok
TakalarAmbon
GondolMaros
Development centre for maricultureResearch Institute for marine and brackish water culture
Thank you for your attention