### I. Taxonomic Classification
- *Class*: Actinopterygii
- *Order*: Perciformes
- *Family*: Rachycentridae
- *Genus*: Rachycentron
- *Species*: R. canadum
- *Binomial name*: Rachycentron canadum (Linnaeus, 1766)
### II. Distribution and Habitat
- *Distribution*: Temperate to tropical waters in the Atlantic, Caribbean, and Indo-Pacific regions.
- *Habitat*: Associated with buoys, reefs, wrecks, and harbors; may enter estuaries and mangroves.
### III. Biology
- *Diet*: Carnivores, feeding on crustaceans, cephalopods, and small fishes.
- *Eurythermal*: Can tolerate temperatures between 1.6 and 32.2°C.
- *Euryhaline*: Can tolerate salinity between 5-44.5 ppt.
- *Spawning*: Multiple times from April to September, with peak in July.
### IV. Breeding and Seed Production
- *Broodstock collection*: Collect subadults (8-15 kg) from the wild or grow-out farms.
- *Quarantine*: Prophylactic treatment to limit disease introduction.
- *Broodstock development*: Feed with highly nutritive diet, rich in vitamins and poly-unsaturated fatty acids.
- *Maturation and spawning*: Induce spawning with hormones (hCG or LH-RHa).
### V. Larval Rearing
- *Larval stages*: Mouth opens at 3-5 days post-hatch (dph).
- *Feeding*: Rotifers (3-10 dph), Artemia nauplii (8-15 dph), and artificial diets (15-18 dph).
- *Green water technique*: Use microalgae to maintain water quality.
### VI. Nursery Rearing
- *Happas or sea cages*: Feed with formulated feed (1200-1800 µ size).
- *Grow-out*: Stock juveniles (15 g) in sea cages or land-based ponds.
### VII. Grow-out Culture
- *Pond culture*: Earthen ponds with muddy bottoms, feed with sinking type of artificial formulated feed.
- *Offshore cage culture*: Circular cages (6m diameter) with HDPE ropes or GI pipes.
### VIII. Harvesting
- *Harvest*: Starve fish for a day, crowd and net or pump fish.
- *Market forms*: Whole, gutted, headless, or filleted.
### IX. Advantages and Challenges
- *Advantages*: Effective use of resources, low investment, simple farming operations.
- *Challenges*: Poaching, dependence on climatic conditions, requirement of skilled labor, nutrient loading, and disease outbreaks.
This structured format provides an overview of cobia biology, breeding, seed production, larval rearing, nursery rearing, grow-out culture, harvesting, and advantages and challenges.
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