Date: 13 August 1998
To: BRINE-L@UGA.CC.UGA.EDU
QUESTION:
I have in our hatchery five 10,000 litres insulated rearing tanks
which are not all that successful for rearing fish unfortunately. I was
wondering whether I could use them for culturing Artemia biomass, to feed fish that we are about to wean onto dry feeds (Artemia nauplii are too small at this stage).
Each tank has a supply of UV and cartridge filtered seawater, a large
immersion heater and a large sodium light above it. What kind of density should I be setting the nauplii up at, and what kind of yield of adults should I expect at the end (14 days?). I have quite a lot of spray dried Spirulina that has been left lying around, so I had thought of using this as a feed or else I will bin it. Is there a better and cheaper food available?
What would be the productivity in wet weight of Artemia if the system works OK?
Brendan Gara <Bgmannin@aol.com>
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COMMENTS 1:
I believe that one of the articles or FAQs at www.brineshrimpdirect.com
has exactly the answers to your questions. They discuss bulk growing
densities, oxygen levels, feeding, etc.
Wright Huntley, Fremont CA, USA, 510 494-8679
huntley1@home.com
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COMMENTS 2:
I would inoculate your tanks with 5000 naups/liter and the Spirulina
should work fine as a food. In two weeks culturing you should have an increase in biomass of some 500 times. Make sure you have adequate filtration (biological) to metabolize the nitrogenous wastes as it is counter productive to have too high a water exchange and flush all that Spirulina out. You may wish to purchase a copy of Manual for the Culture and Use of Brine Shrimp Artemia in Aquaculture, 1986 FAO publication that is available through the Artemia Reference Center and Lab. of Aquaculture at the Ghent University, Belgium (magda.vanhooren@UGent.be) In this publication is a very detailed description of batch culturing Artemia in raceways.
I believe that if you produce at 5000 animals per liter you can count on 70-75% survival to adult. If your water temperature is 27-30 C then I would estimate that you will be able to produce +/-180-200 quarts of live young adult Artemia biomass every 15-20 days.
This of course will depend on your feeding and your ability to maintain optimum water quality parameters. As I recall when we were doing this back in the early eighties we had a crisis period at about day 7-9 that appeared to be related to high nitrogenous wastes. We were doing this in a completely closed system.
You may wish to contact Peter Ericson of Salt Creek Inc. as he was involved in this project on a day by day basis and could probably give you additional valuable information.
Howard W. Newman <BShrimp@aol.com>