Decapsulating Brine Shrimp Eggs

By: | Date: 12/17/2009 | No Comments |
Special thanks to for giving us permission to republish Marc’s excellent article.

Decapsulating of Brine Shrimp Eggs has been in the hobby for quite a while now. When decapsulation is done correctly, not only does it boost brine shrimp hatch rates and makes harvesting a gazzillion times easier, but more importantly it helps kill unwanted hitchhikers and produce artemia with higher nutrition. The downside however is that it is one more step in the breeding process which many home hobbyists feel that they can dispense with. However, as you can see in the rest of the article, the many benefits make decapsulation worth the extra work for many hobbyists (like myself).

Decapsu-What??? – An Introduction

“Decapsulate” basically means “to remove the capsule”. You see brine shrimp EGGS are really brine shrimp CYSTS.. It is really a little CAPSULE which encloses the embryo inside. During dry months, these cysts are capable of drying out (somewhat) completely. During this time, the cysts may be carried by wind over terrain and such before landing in another lake somewhere or subjected to predation by scavengers or harvesting by people for the aquarium trade. This is where the capsule comes in. Each embryo is protected by a strong capsule or shell which allows the cyst to survive the dry months. Decapsulating simply means to remove this outer shell while still leaving the embryo unharmed.

Why Should I Decapsulate?

Well… the reasons are multifold. I’ll try to list them here as completely as I can.

1) Boosting Hatch Rates

As mentioned above, brine shrimp cysts are naturally encapsulated in a very strong and tough shell. During the natural hatching process, the embryo has to first find a way to break through this tough outer shell. During this process, a lot of babies don’t make it and get stuck somewhere along the process. Part of the hatching process involves the babies hanging under the egg in a protective membrane after it has managed to break through the shell. I have seen many cases of babies making it halfway out and getting stuck, as evidenced of the little teardrop shaped membrane suspended under each shell that never completely hatched.

Removing the tough shell allows more babies to hatch without having to overcome the obstacle that is the protective shell.

2) Boosting Nutrition of Newly Hatched Artemia

For the same reason listed above for (1), the removal of the shell allows the babies to hatch much easier. This means that they spend less energy trying to be born. This means that they have more nutrition when they are born. This is related to the next point. Read on…..

3) Decreasing Hatch Times

Since they don’t have a hard shell to overcome, that is a major obstacle out of the way. Hence they are free swimming much sooner than if they were hatched the natural way. The normal hatch times vary from 24 – 30 hrs. With decapsulated eggs however, i have experienced hatch times from as early as 12 hrs, with the typical hatch times being 16 – 18 hrs. As mentioned in point (2), quicker hatch times means that the babies haven’t expended as more energy and hence are arguably more nutritious.

4) Killing Nasty Hitchhikers

Decapsulation is most commonly done with household bleach. According to the little label on my bottle of Clorox, it “kills 99.9% germs on contact”. If it does that “on contact” I cannot imagine the damage it does to the nasties when being soaked in it for 5 min or so. Those of us that rear seahorses know that hydroids can decimate a baby pony corral if gone unnoticed. This is especially true in dwarf seahorse tanks where they are fed BBS extensively.

Decapsulation not only strips off the shell from the cysts, but also kills most of the nasty hydroids (or hydroid eggs or whatever allows them to hitchhike). While some hydroids occasionally do make it into the breeder tank, the numbers are SIGNIFICANTLY decreased with decapsulated eggs. Nowadays all my seahorse fry are only fed artemia from decapsulated eggs.

5) Easy Easy EASY Harvest

Harvest is super easy. Just Pour (or net) with a brine shrimp net, rinse under clean water and straight into the fry tank. No setting up lighting to attract the artemia, no messing around with trying to skim shells, not waiting around for enough artemia to gather around in order to harvest. Just scoop and go. If decapsulation was done correctly, there are no shells to worry about.

6) Unhatched Eggs Can Be Eaten

How many of us have gone over to inspect our fry after feeding only to find that instead of nice orangey bellies, you notice golden / brown little orbs in their bellies…. they’ve eaten unhatched brine shrimp eggs. Usually it is more a nuisance than anything, but sometimes fry seem to have a taste for unhatched eggs. If they eat too much, it can block intestinal tracts, reduce nutrient uptake (by taking up space which would otherwise be filled with BBS) and upset the balance of the fry (because unhatched eggs are more buoyant).

The nice thing about decapsulated eggs is that they are completely edible… and nutritious. I know some people who decapsulate eggs for the sole purpose of feeding the unhatched eggs to their fry. So no worries, if any eggs fail to hatch, just feed them to your fry anyway. They’ll eat them and be totally ok!

How To Decapsulate

Ok… so here’s what you REALLY came to this page for. Here are instructions for you to decapsulate your own brine shrimp eggs.

You will need :

  • Brine Shrimp Cysts (duh!)
  • Your normal 2 liter brine shrimp hatcher* + airpump
  • Bleach – Sodium hypochlorite solution. (Ol’fashioned Bleach. NONE of that flowery smelling, color safe stuff).
  • Table Salt. You can use aquarium salt, but table salt is cheaper and is less likely to leave white precipitate.
  • Brine Shrimp Net or rotifer sieve
  • Dechlorinator (I like “Prime”)
  • Small saucepan or microwaveable container (to heat water)
  • Water (tap water is fine)
  • Measuring spoon (1 cup)

* Instructions on How to Make a 2L Brine Shrimp Hatcher.

Here’s a partial list of stuff you need. Note that step 1 (below) is well underway…..


Step 1 – Rehydrate The Dehydrated Cysts

If you look at the dried cysts under a microscope, you will notice that it is not perfectly spherical. In fact, it looks kinda scrunched up and bumpy. Kinda like those dried prunes that grandma made you eat when you were *ahem* clogged up. This uneven surfaces makes it difficult to uniformly remove the protective shell. When rehydrated, the cyst sucks up water and balloons into a something that looks more spherical, which will help when we are trying to strip the surface shell later.

Hook up your air pump to your hatcher and fill with a cup or 2 of tap water (no salt yet!!). Grab a tablespoon of brine shrimp eggs and add it to the water. Let it it bubble for 1 to 2 hrs depending on the brand of eggs that you have. If you have no idea where your eggs came from or just want to play it safe, then let it rehydrate for 1.5 hrs.


The only accurate way to determine how long to rehydrate is to view cysts under a microscope to determine if they have fully formed into spheres. Too short and your cysts would not have ballooned enough. Too long and the embryo insides starts developing and will definitely be killed later when we dehydrate it again for storage.

Step 2 – Prepare Saturated Brine (Salt) Solution.

This step should be performed while waiting for step 1 to finish. A saturated salt solution will later be used to dehydrate the eggs for storage after decapsulation. The only way to ensure a super saturated solution is to dissolve salt into warm or hot water. This can be done by heating a bowl of water in the microwave and then dissolve as much salt as will dissolve before the liquid cools down. You will know the solution is saturated when the liquid is still warm and no more salt will dissolve in it.

Alternatively you can use a saucepan and heat water on the stovetop while stirring in salt. When the liquid is saturated (no more salt will dissolve), you can take it off the heat and allow to cool. In this pic you can see what happens after cooling for an hour. The salt precipitates out of the saturated solution, forming a ring of salt on the surface and a mound of salt at the bottom.


Now that the cysts are adequately rehydrated and the salt solution is prepared, we are now ready to start decapsulating. The next few steps happen very quickly, so make sure you read the next few steps and understand them thoroughly before you start.

Step 3 – Decapsulating

After an 1 to 2 hrs of rehydrating, prepare 1 to 2 times as much of clorox bleach compared to the amount of water you used to rehydrate the eggs. Again the amount of bleach required is dependant on the brand of cysts that you have. The first time you do this it is pretty much trial and error, but after a couple of times, you will be able to get a feel of how much bleach to use. In my case, I find that it requires twice as much bleach as water i.e. 1:2 ratio. (If I used 1 cup of water to rehydrate the brine shrimp before, now I will need 2 more cups of bleach). Pour the bleach into the hatcher with the cysts already bubbling inside.

Now things become crucial. DON’T TAKE YOUR EYES OFF THE CYSTS FOR THE NEXT 5 – 10 MIN!!!!!!! Depending on the brand of cysts and how much bleach you use, the decapsulation process will take anywhere from 5 to 10 min. If you find that it takes more than 10 min, then you haven’t added enough bleach. Adjust your ratio for the next time round.

You are watching for several color changes…. The cysts start out golden brown at first (before adding bleach)…..


The next color change you are looking out for is WHITE. They cysts will turn white as the brown outer shell gets stripped off.


Then it will slowly turn orangey brown again as the white layer gets removed.


Lastly, it should turn completely ORANGE as the shell is completely stripped off, revealing the orange embryo inside. And no… Do NOT add soy sauce and olive oil !!


Step 4 – Rinse Decapsulated Eggs

The moment the eggs turn orange IT IS DONE!!! Now we need to immediately stop the decapsulation process before the bleach eats through the remaining membrane and kills the embryo inside.

Pour the contents of the hatcher into a brine shrimp net (or plankton sieve) to drain away all the bleach solution and immediately run it under the tap for a few minutes. Rinse it until you can barely smell any chlorine in the net.


Step 5 – Dehydrate Using Super Saturated Brine

Once you are satisfied that you have washed away most of the bleach, turn your attention to the hatcher. Rinse it thoroughly until most of the bleach is gone. Then return the rinsed brine shrimp eggs to the hatcher. Make sure that your super saturated brine solution has cooled to room temperature and pour into the hatcher with the decapsulated eggs.


Step 6 – Allow to dehydrate for at least 12 hrs

I usually add a partial capful of prime in there to make sure that all the chlorine has been removed.


Allow the solution to bubble for about 12 hrs. As the eggs dehydrate due to osmotic pressure, the water coming out of the eggs will start diluting the once super saturated brine solution. After the first 5 hours or so, you may want to add a little bit more super saturated brine or a couple pinches of salt to keep the brine saturated enough to keep pulling water out of the eggs. After 12 hrs or so of dehydrating, the eggs should be ready for medium – term storage

Storing Decapsulated Eggs

There has been a lot of debate about storing decapsulated brine shrimp eggs and for how long you can store them for. Some places tell you to simply store them in a tupperware in super saturated brine in the fridge, some places tell you to store them dry in 100% salt. While the latter actually preserves the decapsulated cysts much better and ensures a much better hatch rate, good luck trying to separate eggs and salt when it comes time to hatch them. It’s going to be a nightmare to ensure that you have the correct salinity to hatch the eggs as it is unavoidable that you will pick up some salt along with the eggs. The first method is ok, but as eggs continue to dry out and the storage solution becomes less and less salty, there is always a risk that the brine solution may become dilute enough such that fungus may start to grow on the eggs. I found the best way is to combine the above two methods.

After allowing 12 hrs for dehydration, pour the eggs through a brine shrimp net again to drain away all the water. Transfer the eggs to a little tupperware (I like these tiny ones). Pour enough fresh super saturated brine solution over the eggs to cover them by at least 1/2″. On top of that, add a pinch of granulated salt into the solution so that it forms a very thin layer of solid salt granules. Mix everything up.

Harvesting is easy, have a little pipette or syringe ready. Give the container a good shake. All the salt granules will settle to the bottom first. Next the eggs will settle on top of the salt layer. Harvesting is as simple as sucking up the top layer of eggs with the pipette. When you get real good at it, you will be able to notice that if you tilt the container at certain times while the layers are settling, you will be able to get a good thick layer of eggs at the corners which you can very easily suck up.

In order to keep the eggs in tip top shape, make sure that there is always a certain amount of salt granules with the eggs. In the even that you no longer see any salt granules, it means that the solution has become diluted and hence caused the salt to dissolve. If that happens, simply add a couple pinches or salt to the container.

Hatching After Decapsulation

Hatching is exactly the same as hatching cysts that are not decapsulated. 1 quart of water + 1 tablespoon of salt + bring shrimp cysts. The only difference is that you will notice that BBS will start to hatch much earlier. Check the hatchery at about 16 hrs and you should be able to partially harvest the ones that have already hatched. Unhatched eggs will sink to the bottom so all you need to do is skim the surface with a brine shrimp net to pick up any ones that have already hatched. Keep areating unhatched eggs for a couple more hours and you will be able to do a second harvest 4 – 5 hrs later.

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