Milkfish Culture (Chanos chanos)

Milkfish is exceptionally well-suited for Sri Lankan aquaculture due to:

• Wide salinity tolerance (0-60 ppt) - can be cultured in fresh, brackish, or marine water
• Fast growth rate - reaches 500g in 4-6 months
• Hardy nature - resistant to diseases and environmental stress
• Natural food utilization - feeds on algae and detritus
• High market demand - popular in local and export markets
• Established technology - proven culture methods available

Milkfish can be cultured in various systems:

• Traditional ponds: Extensive culture with natural food (lab-lab)
• Modified extensive: Improved traditional with supplemental feeding
• Semi-intensive: Higher stocking with regular feeding
• Intensive ponds: High density with complete feeding
• Cage culture: Marine or brackish water cages
• Pen culture: Enclosures in shallow coastal areas

Each system varies in investment, management intensity, and production levels.

Lab-lab is a benthic algal mat that serves as natural food for milkfish:

• Composition: Blue-green algae, diatoms, and associated microorganisms
• Preparation: Dry pond, apply organic fertilizer (chicken manure)
• Water management: Gradual flooding to 10-20cm depth
• Development time: 2-3 weeks for mat formation
• Maintenance: Regular fertilization and water level control
• Benefit: Reduces feed costs by 40-50%

Proper lab-lab management is crucial for successful extensive culture.

Stocking density varies by culture system:

• Extensive (traditional): 3,000-5,000/ha → 500-800 kg/ha/crop
• Modified extensive: 5,000-8,000/ha → 1-1.5 tons/ha/crop
• Semi-intensive: 10,000-20,000/ha → 2-4 tons/ha/crop
• Intensive: 30,000-50,000/ha → 5-10 tons/ha/crop
• Cage culture: 30-50 fish/m³ → 15-25 kg/m³

Higher densities require better water management and supplemental feeding.

Milkfish feeding varies by culture stage and system:

• Fry (0.02-1g): Fine powder feed, 40% protein, 8-10% body weight
• Fingerlings (1-20g): Crumbles, 35% protein, 5-8% body weight
• Juveniles (20-100g): Pellets 2-3mm, 30% protein, 3-5% body weight
• Grow-out (>100g): Pellets 4-5mm, 25-28% protein, 2-3% body weight

FCR ranges from 1.5-2.5 depending on management. Natural food (lab-lab) significantly reduces feed requirements.

Culture duration depends on target market size:

• Fingerlings (20-50g): 45-60 days from fry
• Small market size (200-250g): 3-4 months
• Standard market (400-500g): 4-6 months
• Large size (800-1000g): 8-10 months
• Export size (>1kg): 10-12 months

Farmers typically harvest at 400-500g for optimal economic returns. Multiple crops (2-3 per year) are possible in tropical conditions.

Optimal water parameters for milkfish culture:

• Temperature: 25-32°C (optimal 28-30°C)
• Salinity: 15-30 ppt (tolerates 0-60 ppt)
• Dissolved oxygen: >4 mg/L (critical >3 mg/L)
• pH: 7.5-8.5
• Ammonia: <0.1 mg/L
• Transparency: 30-40 cm
• Water depth: 0.8-1.5 m for ponds

Regular water exchange (10-30% daily) maintains quality in intensive systems.

Milkfish is generally hardy but may face:

• Bacterial infections: Vibriosis, Streptococcosis - treat with probiotics
• Parasites: Caligus, Trichodina - freshwater bath treatment
• Nutritional disorders: Vitamin C deficiency - proper feed formulation
• Environmental stress: Low DO, high ammonia - water management

Prevention through good water quality, proper stocking density, and regular health monitoring is key. NAQDA provides disease diagnostic services.

Milkfish has strong market demand:

• Local market: Rs. 400-500/kg fresh whole fish
• Processed products: Rs. 600-800/kg (deboned, smoked)
• Export market: $3-5/kg frozen whole
• Value-added: $8-12/kg (fillets, ready-to-cook)
• Live fish: Rs. 600-700/kg for restaurants

Annual demand in Sri Lanka exceeds 5,000 MT with growing export potential to Philippines, Indonesia, and Middle East markets.

Yes, milkfish works well in polyculture systems:

• With shrimp: Milkfish controls algae, improves water quality
• With tilapia: Different feeding zones, increased production
• With mud crab: Milkfish in water column, crabs on bottom
• With seaweed: Integrated multi-trophic aquaculture

Polyculture can increase total production by 30-40% and improve pond ecology. Proper species ratio and management are essential.

Economic analysis for 1-hectare semi-intensive pond:

• Pond development: Rs. 500,000-800,000
• Working capital: Rs. 300,000 per crop
• Production: 3-4 tons per crop (2 crops/year)
• Gross revenue: Rs. 1.2-1.6 million/year
• Net profit: Rs. 400,000-600,000/year
• ROI: 30-40% after first year

NAQDA provides subsidies up to 50% for pond construction and technical support.

Steps to begin milkfish farming:

1. Site selection - coastal brackish water area or inland saline land
2. Obtain NAQDA aquaculture license and permits
3. Pond construction or rehabilitation
4. Water source development and lab-lab preparation
5. Source quality fingerlings from certified hatcheries
6. Stock and manage according to chosen system
7. Regular monitoring and maintenance
8. Harvest at market size and establish market links

NAQDA provides training, fingerlings, and complete technical support for new farmers.