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6.4. Hatching of eggs
Unit 6 - Breeding of common carp
6.4. Hatching of eggs
- The developing eggs which are attached to the substratum are transferred to hatching hapa or circular tank for hatching where running water is maintained.
- The eggs are adhesive, small (1-2 mm diameter), with narrow perivitelline space, spherical and pale-yellow (fertilized).
- Unfertilized eggs are opaque white.
- The stocking density of eggs is 50,000 - 1,00,000 eggs per hapa (2 x 1 x 1 m) or 25-30 lakh eggs per circular hatching tank.
- The eggs hatch in 36 – 72 hours 26 – 31oC.
- The newly-hatched spawn is heavy (remain attached to hapa wall), 4-5.6 mm long, with prominent eyes.
- The yolk-sac spawn remains in the hapa or tank till it becomes free-swimming.
- Yolk-sac is completely absorbed in 3-4 days.
- After the yolk-sac absorption, the spawn is transferred to a prepared nursery pond for on-growing to fry/fingerling stage.
- In the nursery pond the spawn is fed with a mixture of rice bran and oil cake (1:1 ratio) till they reach fry stage in 15-20 days.
Last modified: Tuesday, 14 June 2011, 12:10 PM