ARTEMIA FEEDING RATES

Date: 24 March 1999
To: BRINE-L@UGA.CC.UGA.EDU

QUESTION:

Does anybody on the list know the approximate filtering rates (mls/ animal/day) for Artemia immediately after they start feeding ? Is there a difference between algal cells and oil emulsions?

Brendan Gara

Bgmannin@aol.com

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COMMENTS 1:

There are references in Volume 2 of "The Brine Shrimp Artemia", Sorgeloos et al. 1979, entitled: The feeding of Artemia on Phaeodactylum tricornutum by J. G. Braun (page 197) and Volume 2 of the three volumes "Artemia, Research and its Applications", Sorgeloos et al. 1987, entitled: Evaluation of mono and mixed diets as food for intensive Artemia culture, by Patrick Lavens et al. (page 309). In this same volume there are other papers presented on culturing with rice bran by R.R. Platon (pg. 347), R. Yashiro, entitled: The effect of Artemia fed with different diets on the growth and survival of Penaeus monodon Fabricius postlarvae (p. 447).

If the diet fed to Artemia is one that is easily digestible I
don't believe that it makes too much difference on the actual number of cells.
On the other hand if the algal cells are difficult to break down and the cells are plentiful, then it appears that the Artemia pack to food too quickly and it is excreted undigested. I cannot at this point cite the reference but it was done with Artemia franciscana SFB strain on the biomass collected from salterns around SFBay.

On your question about algal cells vs emulsions: the emulsions are fed
only during an enrichment period (up to 48 hours but most likely 24 hours) prior to feeding the adult biomass or the nauplii to a target organism. For ongrowing Artemia nauplii they must be fed either an acceptable alga or inert diet.

Howard W. Newman
Inve Aquaculture, inc.
hwnewman@inve-us.com

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COMMENT 2

As to Brendan's specific question, the only listing of any type I've come across so far was on the Live Foods List. An aquatic biology instructor mentioned that his classes were blending a tablespoon of Spirulina in a liter of water, blending them for about four minutes. After straining through an Artemia net for particle size, 50 cc per 20 l of culture were applied to the tanks. His only reference to frequency, though, was that they waited until the water had cleared of both the algae and the resultant bacterial bloom...
As an addition to that, the USGS site on Artemia's impact to the Utah economy states that in times of reduced food availability, the shrimp can even "recycle" fecal pellets excreted earlier in the season. I've found this to be true in my own cultures, as I can often stop feeding them for a period prior to cleaning the tanks - I let them do some of the work.

David A. Youngker

e-mail: nestor10@mindspring.com

http://www.mindspring.com/~nestor10
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