Decapsulated Artemia

By
Alan Dunne
©www.Livingfish.co.uk
2002

By far the best live food you can get for the fish hobby today is live newly hatched brine shrimp. There are a couple of problems that occur with this shrimp which I hope I can help, firstly the dreaded egg shells and secondly, 6 hours after hatching, they burn off around 20-30% of their stored energy (this is what you want to feed to your fish), remember from the first hatching to 80% hatch their may be 5 hours so the brine shrimp that hatched in the first 3 hours will have wasted a lot of energy, so if you then leave them even longer the less nutritious they become to you fish.

There is a way of removing the shell of the brine shrimp so when you hatch it you don't have the hassle of siphoning off brines shrimp from the egg shells, this is done by dissolving the shell off the unhatched shrimp in a weak bleach solution, you then either hatch the brine shrimp as normal or feed the unhatched cysts directly to the hungry fish, remember the unhatched brine shrimp cysts has not wasted any energy on hatching or swimming around the hatching tank, so is by far the better for the fish.

When you have measured out the amount of the brine shrimp eggs you want, put them it to fresh or salt water for 1-2 hours to hydrated (to absorb water into the egg, as the eggs you get are dried to last longer), then pore the eggs through a fine mesh net and you should catch 95% of the eggs, make up a water solution with costic soda until you have a pH of 10.5 plus (only a small amount costic soda is needed, especially is soft water areas).

Then add 5ml of industrial strength bleach to 1 litre of the solution (1ppm), but household bleach will do, you will need around 10-15ml per litre, remember it dose not have to be exact, but the more bleach you add the faster it works and the less bleach the slower it works.

Add the hydrated eggs to the solution then watch and mix slowly, the eggs will slowly turn white then turn orange (the time depends on the temperature and the amount of bleach used, but is usually around 20 minuets) you then pore the orange cysts back through the fine mesh net, one problem is that costic soda and bleach mixed together makes an exothermic reaction (self warming) and if the temperature gets above 40°C you won’t be able to hatch them.

Next have a litre of normal tap water, using sodium thiosulphate at an concentration of 0.1%, pore it over the cysts to neutralize the chlorine from the bleach, then wash under normal tap water, or use normal tank declorenator then wash the eggs in this to remove any bleach left on the eggs, as if any bleach is left on the eggs it would soon kill the Artemia in the eggs or if feed to the fish it could kill the fish.

Smell the cysts to check it’s free of chlorine, if you can smell chlorine wash again.