GROUP 1_NARRATIVE REPORT_LWE 424

BASIC BIOLOGICAL CHARACTERISTICS AND REQUIREMENTS OF IMPORTANT AQUACULTURE SPECIES

Key Parameters to Consider in Aquaculture

• Site Selection and Biological Characteristics

  • Suitability depends on species' needs: salinity, temperature, dissolved oxygen, and water quality.

  • Species with high salinity tolerance can be cultured in marine or brackish water.

  • Temperature affects growth rates; some thrive in warm waters while others prefer cooler conditions.

  • Oxygen demand varies: species with high metabolism need well-oxygenated water.

• Species Selection

  • Should align with growth rate, feed efficiency, adaptability, and disease resistance.

• Water Management

  • Water quality impacts metabolism, growth, immune function, and survival.

  • Euryhaline species tolerate a range of salinities; stenohaline species require stable conditions.

  • pH and ammonia tolerance are vital; species sensitive to nitrogen need filtration and exchange.

• Nutrition and Feeding

  • Dietary needs vary based on the digestive system and natural habits.

  • Growth rates depend on feed conversion efficiency (FCR); lower FCRs are more economical.

  • Overfeeding can lead to pollution, hence careful feed management is essential.

• Environmental and Sustainability Considerations

  • Sustainability accounts for ecological impact while maintaining productivity.

  • Stocking density can influence stress and disease risk; high-density systems need better water quality control.

SELECTION CRITERIA AND CHARACTERISTICS OF IMPORTANT AQUACULTURE SPECIES

Major Cultured Aqua Species in the Philippines

• Tilapia: Widely farmed due to rapid growth and adaptability.

Important Tilapia Species

Nile Tilapia (Oreochromis Niloticus)

• Introduction: Introduced in 1950; now thrives in varied environments.

• Biological Characteristics:

  • Habitat & Temperature Preferences: Prefers shallow, warm waters (31-36°C).

  • Diet: Omnivorous, feeds on phytoplankton, aquatic plants, and small invertebrates.

    • Reproduction & Spawning: 5-6 months to maturity; mouth-brooding with maternal care.

  • Lifespan: Over 10 years; max weight over 5 kg.

Mozambique Java Tilapia (Oreochromis mossambicus)

• Tolerant of brackish waters but slower growth limits its viability.

Red Tilapia (Oreochromis spp. hybrids)

• Hybrid known for its market appeal, suitable for coastal farming.

Blue Tilapia (Oreochromis aureus)

• Cold-tolerant, often used in research for developing cold-resistant hybrids.

Blackchin Tilapia (Sarotherodon melanotheron)

• Paternal mouthbrooder, carnivorous, may disrupt local ecosystems when introduced.

SHRIMP/PRAWNS

Major Shrimp Species in the Philippines

• Penaeus monodon (Giant Black Tiger Shrimp):

  • Largest commercially available shrimp, dark colored with growth up to 336 mm.

  • Habitat and Behavior: Found in various depths, tolerates salinities of 5-45 ppt.

  • Mating and Reproduction: Complex life cycle with multiple larval stages; females can produce 500,000 to 750,000 eggs.

• Penaeus vannamei (Pacific White Shrimp):

  • Among the top commercially important species, requires >20°C temperature.

  • Reaches market size in 3-4 months at optimal conditions.

WATER QUALITY MANAGEMENT

Importance in Shrimp Farming

• Water quality directly affects growth and survival:

  1. Salinity: Level should be monitored for growth; ideal for juvenile shrimps varies.

  2. pH: Optimal range is 7.5 to 9.0 to sustain shrimp production.

  3. Dissolved Oxygen (DO): Necessary for respiratory needs; regular aeration is critical.

  4. Nitrogen Compounds: Monitoring ammonia levels is essential; can decrease shrimp growth if high.

  5. Temperature: Water temperature crucially regulates shrimp metabolism; ideal range is 25-30°C.

SEAWEED CULTURE

Site Selection Criteria

• Moderate water movement and sunlight penetration are essential.

• Sufficient depth to avoid exposure at low tide.

• Use of materials like nylon, bamboo, and proper tying techniques for growing seaweed.

MILKFISH CULTURE

Site Selection Criteria for Milkfish (Chanos chanos)

• Minimum water depth 0.8-1 m; salinity of 10-30 ppt, pH of 7.5-8.5 are optimal.

• Preparation of nursery ponds includes draining, liming, and fertilizing for natural food growth.

• Nurturing fry until they reach market size in controlled environments.

ENVIRONMENTAL AND WATER QUALITY REQUIREMENTS

Key Environmental Factors

• Physical Variables: Temperature, density, freezing point, salinity, turbidity.

• Chemical Variables: Dissolved oxygen, total alkalinity, and hardness.

• Biological Factors: Parasite and predator control, species selection, and social and economic factors like facility type and market strategies.

Conclusion

To ensure successful aquaculture, one must align farming practices with the biological needs of cultured species, emphasizing water management, nutrition, and sustainability.