Date: 16 January 1999
From: Sheryl Quinn <SeaSlugg@aol.com>
To: BRINE-L@UGA.CC.UGA.EDU
QUESTION:
I work at an aquaculture facility located in Oxnard, CA. We are in the
beginning stages of raising white seabass. We are still working out a few kinks in our Artemia production system and could use some help. After reading several books on the subject I understand that decapsulated Artemia cysts may be stored for up to a week in the refrigerator, but I have been unable to determine the proper storage method. Should they be stored in water? Do they need to be kept aerated?
Sheryl Quinn
Proteus Sea Farms, International
Oxnard, CA
email: seaslugg@aol.com
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COMMENTS 1:
It is my understanding that they can be stored almost indefinitely in
the refrigerator. The trick is to effectively re-dehydrate them by
storing in saturated brine solution. They stay in suspended animation
until you lower the salt density.
There have been commercial products based on this ability to store them for long periods after dechorionating. I haven't seen any lately, but it used to be possible to buy decap hatchable eggs at your lfs.
Wright Huntley
Fremont CA, USA,
510 494-8679
e-mail: huntley1@home.com
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COMMENTS 2:
Decapsulated cysts that are not used for hatching right away can be stored for later hatchings. Drain or remove all excess water from the decapsulated cysts. Add brine water (300+ ppt salinity) until the cysts are completely covered. The brine water will pull the water out of the cysts or dehydrate them again. If the cysts are to be stored for several weeks to a month, replace the old brine water with new brine water after 24 hours. Store the decapsulated cysts (in brine water) in the refrigerator for up to one month.
Mike Stankiewitcz
e-mail: marine@zdial.com
http://MikesMarine.gen.com
MikesMarine@gen.com
ICQ:1547283
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COMMENTS 3:
Store the decapsulated cysts in saturated sodium chloride, refrigerated and they will keep for months.
Howard W. Newman
Inve Aquaculture, Inc.
e-mail: BShrimp@aol.com
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COMMENTS 4:
We have been using the decapsulated Artemia cysts for the past couple of years. I use the 1 lb cans and they can be kept in the fridge for a very long time. You only add water if adding them to a tank and they don't need aeration since they are not live and will not hatch if you try to hatch them. I have one can that has not been opened for almost a year and so far I know they are still good. All they are is Artemia cysts that have had the shells removed. These will not hatch.
Darren J. Hanson
e-mail: djhanson@calweb.com
http://www.calweb.com/users/d/djhanson/index.htm
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COMMENTS 5:
Decapped cysts (live) normally hatch at a bit higher rate than regular
from the same source. D. Hanson is talking about the dehydrated (actually completely 'dry' and dead) cysts from sources like Brine Shrimp Direct that are a good food for fish that don't need wriggling to trigger the feeding reflex. Most aquaculture applications feel they can't use them. They are a fine substitute for live brine shrimp for fish familiar with the color and taste, and that are mature enough to take non-living food.
Since they can be made from low-hatch-rate eggs and are hence cheap, maybe the aquaculture folks should experiment and see if they can't use them at some stage in their process.
Wright Huntley
Fremont CA, USA
510 494-8679
e-mail: huntley1@home.com
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COMMENTS 6:
Yes, there is a difference between what D. Hanson is talking about and what Sheryl was referring to for her white seabass larvae. The NON-hatching ShellFree Decapsulated Artemia cysts are highly acceptable to many species as a direct food. There is an advantage in feeding the non-hatching variety for increased caloric content and the smaller size for ingestion. However, there are some concerns that marine fish larvae in the early stages cannot break down the hatching membrane surrounding the Artemia embryo, thereby not being digestible. This does not seem to be a problem with freshwater fish larvae....cannot explain the difference, except maybe the length of the digestive tract?
The hatching variety is merely a good hatching Artemia cyst that has been decapsulated. Normally the decapsulation is done and the cysts are then placed in a container for incubation. However, when one does not wish to decapsulate on a daily basis a larger quantity can be decapsulated and stored in saturated brine, refrigerated, until needed.
Howard W. Newman
e-mail: BShrimp@aol.com
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COMMENTS 7:
It is likely that the larvae of marine fish need the digestive enzymes
which are present in the gut of baby brine shrimp (and other prey). For
example turbot larvae have almost no such enzymes in the first stages of their larval development, so when one feeds decapsulated cysts to these larvae, they might not be able to digest enough food because they lack the proper enzymes which facilitate digestion.
Personally I would be careful with decapsulating large batches of cysts, especially if one is not familiar with the procedure. The larger the batch the more difficult it is to precisely control the decapsulation
process. It is very easy to offset the advantages of decapsulation by
destroying a percentage of the cysts due to destruction of the outer
cuticular membrane, which surrounds the embryo.
I would also not keep the decapsulated cysts for too long a time, should one be working with living cysts. Decapsulate the cysts, dehydrate them in a saturated brine solution (hereby changing the brine a couple of times as the salinity decreases due to the cysts loosing water) and store them in a cool place. I would suggest to hatch the decapsulated cysts within a week ... but that's just me ...
The cysts which you find in the small, brown SFBB jars do indeed contain cysts derived from the Commonwealth of Independent States. These cysts are larger compared to the A. franciscana SFB cysts and have a lighter colour. Do not try to decapsulate these cysts as you will end up killing a lot of cysts, you will lower the hatching efficiency of the product!
Steve Geerts
e-mail: stevege@hotmail.com