The Free On-line Aquaculture Dictionary |
Decapsulation of brine shrimp |
Sodium hypochlorite method | Calcium hypochlorite method |
Why Decapsulate? There are several advantages for decapsulating or removing the thick outer shell (chorion) of the brine shrimp cyst.
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Method
1 – Sodium hypochlorite per 500g cysts Requirements – 4.77 litres sodium hypochlorite (6.5% chlorine) 75 g sodium hydroxide 2.2 litres fresh or seawater Freshwater 3 litres Dissolve the sodium hydroxide in the water and allow to cool. Rehydrate the cysts in 3 litres of well aerated fresh water for 30 – 60 minutes. Add cysts and hypochlorite to sodium hydroxide solution. Cysts will change from brown to orange., after 4-5 minutes, when orange colour is detected, pour quickly through a sieve and rinse with freshwater. To ensure decapsulation has finished, stir cysts in 0.1 normal HCL for 30 seconds to neutralise the chlorine. Sieve and rinse again. Temperature should not be allowed to exceed 37oC during decapsulation, and ice may be added to maintain low temperature. |
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Method 2 – Calcium Hypochlorite per 500g cysts 325g calcium hypochlorite 340g soda ash 675 litres fresh or seawater Dissolve all the calcium hypochlorite in 3.38 litres of the water, and in a separate container dissolve the soda ash in the remaining water. Allow for any insoluble particles to settle and decant. Discard the settled solids. Rehydrate the cysts in fresh water with rigorous aeration and add mix the cysts and the two solutions together. Decapsulation occurs within 5-7 minute (when the cysts begin to turn orange from brown). Then proceed as per method 1. |