Artemia cysts won't decapsulate

[RichardinMa]

I tried decapsualting some Artemia this evening and it did not go so well. I am not sure what I may have done wrong and would appreciate any input from others that have had the same experience. The eggs I used are several years old but have been stored in an airtight container in the refrigerator. Hatch rate is pretty good even without decapsulation. I watched a few videos and read several websites that explain how to do this and it seemed relatively straight forward. What I did and what happened:

Using a 2-liter soda bottle style hatcher with aeration I filled the container up about half way with tap water. I added 1/8th of a cup of artemia cysts, turned on the pump and let them hydrate for about 2.5-3 hrs. I then drained off the majority of the water and added bleach at 2 times the remaining volume of water. I let the pump run and watched for color change. At around 3 minutes or so I noticed the cysts turn white. Within another 3 minutes or so I saw the color change back to a creamy brown, nearly the same color as it started. I left them in this solution for several more minutes. At around 10 minutes there was still no further color change even though there was now a foamy layer on the surface of the water, similar to a head on Guiness beer.

At this point I drained the cysts and rinsed them worried that I may just be misreading the color. After doing this I could see that the cysts still looked very much like round brown eggs. I then put them back into straight bleach and let them aerate even longer, some went as long at a half hour, but the cysts never went to orange. I don't understand what I may have done wrong. The bleach was not old. I wondered if perhaps the quantity of eggs was just too much for the amount of bleach but I would have thought that half an hour in straight bleach would have done something. Unfortunately I do not have a microscope handy to see the details of them at this point. I finally gave them a good final rinse and put the majority into a concentrated brine solution to store them in the fridge. I also put some back into a hatcher to see what kind of viability I have on this batch now.

Any ideas what went wrong?

Thanks

 

[reefstew]

You over bleached them & aerated them to long. I use 2 oz of water & 2 teaspoons of eggs & aerate for 1 hour & then add the same amount of bleach & stir for 5 minutes & rince for 4 minutes under cold water & then soak them in water & a small amount of white vinagar & rince again. Check the temp of the eggs when you add bleach & if it gets above 75* add an ice cube.

 

[RichardinMa]

Thanks for the info. I actually figured it out. After microscopic exam of the eggs, I determined that they eggs were, in fact, decapsulated, however the yolks on much of them were a pale grey color rather than bright orange which is why I never got that bright orange hue to the container. I repeated the process the following night and stopped the process after just a few minutes, as soon as they changed from white back to tan. I could examine the cysts under the microscope throughout the process and monitor the degree of decapsualtion and verified that they yolks were indeed very pale.

 

[Luis A M]

I never find problems with my method: http://www.marinebreeder.org/forums/viewtopic.php?f=144&t=3900
You don´t need to drain before bleaching,hydrate in one part and then add 2 parts bleach.
You obviously overbleached.Regardless of the colour you see,try to stay in the 3-5 min range.
And then rinse under the tap for a long time.
Lastly,you can skip the storage in brine.You can decap and keep in the fridge for at least 20 days:thumbsup:

 

[billsreef]

The method Luis uses works very well. One note to add on the FW soak. Much past 1 hour on that soak and hatch rates drop. Might not be very noticeable with small volumes, but it's quite noticeable when your hatching large volumes of cysts.