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Re: Live Foods Digest V2 #99

Live Foods Digest wrote:

> Non-member submission from ["Leng Yee" <lengyee at cheerful_com

> >  I've just started a daphnia culture 2 days ago using live daphnia that I've purchased at a LFS. I'm feeding them wheat flour and so far it seems that some are surviving and congregating at the surface. However, I can't really tell if they're multiplying. Also, there're patches of dead daphnias settling on the bottom of the container, which I presumed were already so when I brought the daphnia from the LFS. Do I siphon the dead ones out or should I leave them?
> >  Also, is it normal to expect the daphnia to continually die off and settle at the bottom?
> >  TIA,
> >  Leng Yee

Hi, Leng,

Daphnia congregate at the surface practically ONLY when dissolved oxygen
is low, assuming that they are NOT being poisoned! With a two-day
culture it could be either cause.

As an emergensy measure, I would siphon all the dead Daphnia and about
50% of the water. Slowly replace the water with preferably FILTERED
(coffee filter) aquarium water, to make certain that the water you used
for the culture is OK.

Next, feed LIGHTLY with YEAST, the kind you buy dry in an envelope at
the supermarket. (I found Fleishman's to work best) Dissolve some of the
yeast, as per directions, and feed the culture dropwise. A slight haze
is just about enough food. 

You probably overfed with the flour and created low oxygen level
conditions. Contrary to general assumptions, Daphnia is a delicate
species, that is why it is being used as a test animal for water
pollution. It does NOT like water movement (as in aeration) nor rapid
change in water parameters. 

You CAN use flour to feed Daphnia, but you must be VERY careful not to
overfeed. Daphnia will survive about a week without any food, so do not
worry that you will starve them.

As soon as your culture is stabilized, divide it itnto two (or more)
just to have another culture, should one culture "crash" (it happens!).

Please, let me know how you did.