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8.5. Hatching
Unit 8 - Breeding of trouts
8.5. Hatching
- Eggs incubated undisturbed until the eyed-stage, in hatching troughs, vertical incubators or hatching jars.
- Hatching and rearing troughs are 40-50 cm wide, 20 cm deep and up to 4 m in length.
- Two layers of eggs are placed in wire baskets or screened trays.
- Water flow rate is 3-4 l/minute.
- As the eggs hatch, the fry drop through the mesh to a bottom trough.
- Some times up to 16 trays are stacked one above the other.
- Hatching period is 100 days at 3.90C or 21 days at 14.40C.
- Dead eggs are periodically removed to limit fungal attack.
- Fugal infection is controlled using formalin (37% solution of formaldehyde) for 15 minutes.
- Hatching rate is up to 95%.
- Yolk-sac absorption period lasts for 2-4 weeks.
- After hatching, the trays are removed and trough water depth is maintained at 8-10 cm until swim-up stage
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After yolk-sac absorption, the fry actively actively search for feed.
Developing Trout eggs
Last modified: Thursday, 16 June 2011, 10:38 AM