![CRAB AND ITS
CULTURE
Presented by: [Muhammad Ahsan Iqbal]](https://image.slidesharecdn.com/crabanditsculturedetailedpresentation-250619172032-daf758a9-250627122703-23d8e518/85/Microsoft-Office-365-Crack-Product-Key-Latest-2025-1-320.jpg)
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- 1. CRAB AND ITS CULTURE Presented by: [Muhammad Ahsan Iqbal]
- 2. Introduction to Crabs โข Crabs are crustaceans from the order Decapoda, characterized by a hard exoskeleton and five pairs of legs. โข Found across marine, freshwater, and even terrestrial ecosystems.
- 3. โข Play key roles as scavengers, helping decompose organic matter and maintain ecological balance. โข Over 6,800 species have been identified globally, with notable species including: โข Mud Crab (Scylla serrata) โข Blue Swimming Crab (Portunus pelagicus) โข Fiddler Crab (Uca spp.)
- 4. Mud Crab Blue Swimming Crab
- 5. Fiddler Crab
- 6. Taxonomic Classification โฆ Kingdom: Animalia โฆ Phylum: Arthropoda โฆ Class: Malacostraca โฆ Order: Decapoda โฆ Infraorder: Brachyura
- 7. Biological Features โข Exoskeleton (carapace) made of chitin provides protection and support. โข Decapods: 10 limbs โ first pair modified into pincers (chelae). โข Sexual Dimorphism: Males often have larger claws; abdomen shape differs (V-shaped in males, U-shaped in females).
- 8. Reproductive Cycle: โข External fertilization โข Lifecycle stages: Zoea โ Megalopa โ Juvenile โ Adult โข Female can produce hundreds of thousands of eggs per brood โข Molting: Crabs shed exoskeletons to grow; a vulnerable period requiring protection.
- 10. Economic and Ecological Importance โข High market value: Crabs are considered a delicacy globally. โข Major source of export revenue in coastal countries (e.g., Southeast Asia, West Africa). โข Support livelihoods for fishers, farmers, traders, and processors.
- 11. Ecological roles: โข Control of detritus and algae โข Food source for birds, mammals, and fish โข Maintain sediment structure through burrowing โข Contribute to coastal ecosystem health.
- 12. What is Crab Culture? โขCrab culture refers to rearing crabs in controlled or semi-controlled aquatic environments. โขFocused primarily on mud crab (Scylla serrata) and blue swimming crab (Portunus pelagicus).
- 13. โขTwo major types: โขGrow-out farming: Juvenile crabs raised to market size over several months. โขFattening: Thin or underweight crabs are fed intensively for 2โ4 weeks to improve meat yield. โขMethods: Pond, cage, pen, or hatchery- based systems.
- 14. Site Selection โข Ideal locations: Brackish water areas, estuaries, mangrove creeks. โข Water requirements: โข Salinity: 10โ35 ppt โข pH: 7.5โ8.5 โข Dissolved Oxygen (DO): โฅ 5 mg/L โข Tidal exchange improves water quality and oxygen levels.
- 15. โข Avoid areas prone to pollution, heavy flooding, or human disturbances. โข Proximity to markets reduces transport costs and mortality.
- 16. Pond and Cage Preparation โขPond Preparation: โขDrain and dry pond bottom to eliminate pests and pathogens. โขApply lime to neutralize acidity. โขFertilize with organic manure to stimulate plankton growth (natural food).
- 17. โขCage Systems: โขFloating or fixed cages in rivers, canals, or estuaries. โขMaterials: Bamboo, PVC frames with netting. โขShelter (tiles, pipes) reduces cannibalism. โขStocking enclosures must be secure to prevent crab escape.
- 18. Pond Culture Cage Culture
- 19. Seed Collection and Stocking โข Sources of seed: โข Wild-caught juveniles from mangroves and estuaries. โข Hatchery-produced seed (more sustainable). โข Stocking size: Juveniles 5โ10 cm across the carapace.
- 20. โข Stocking density: โข Ponds: 1โ3 crabs/mยฒ โข Cages: Depends on size and water exchange โข Ensure uniform size to minimize cannibalism.
- 21. Feeding and Nutrition โขCrabs are opportunistic omnivores. โขNatural feeds: Molluscs, small crustaceans, decaying organic matter. โขSupplementary feeds: โขTrash fish, chopped clam meat, and formulated pellets. โขCommercial feeds enriched with protein and minerals. โขFeeding schedule: โขTwice a day: morning and evening. โขOverfeeding leads to waste and water pollution. โขProvide hideouts to reduce aggression during molting.
- 22. Water Quality Management โขMaintain optimal water parameters: โขpH: 7.5โ8.5 โขSalinity: 10โ35 ppt โขDO: โฅ 5 mg/L โขTemperature: 25โ32ยฐC โขWater exchange: 10โ30% every week, especially in stagnant systems. โขUse aerators in intensive systems. โขMonitor ammonia and nitrite levels to prevent toxicity. โขRegular cleaning to prevent disease outbreaks.
- 23. Harvesting Techniques โขCrabs are harvested when they reach market size (500โ 1000 g). โขHarvesting time: 4โ6 months after stocking. โขHarvesting methods: โขBaited traps or lift nets โขHand collection during low tide โขGrading by size and sex โขFattened crabs can be sold at a premium price. โขCrabs are kept alive for market using moist sacks or oxygenated tanks.
- 24. Challenges in Crab Culture โข Cannibalism: Especially during molting. Use shelters and grade crabs by size. โข Disease outbreaks: Shell rot, bacterial infections (e.g., Vibrio). โข Seed scarcity: Dependence on wild seed is unsustainable.
- 25. โข Climate change: Temperature and salinity fluctuations affect growth and survival. โข Market fluctuations: Export bans or low demand can affect prices. โข Need for training and technical support for small- scale farmers.
- 26. Conclusion โข Crab aquaculture presents a promising solution for coastal livelihoods, economic growth, and food security. โข With continued innovation, training, and environmental stewardship, crab culture can become a pillar of sustainable aquaculture. โข It is a viable career and business path for communities, especially in tropical and subtropical regions. โฆ โSustainable crab farming is not just a practiceโitโs a pathway to ocean-friendly food and economic empowerment.โ