Re: [Killietalk] Rotifers, Daphnia by the pound

["George Davis" <gwd at magpage_com>]

    Reading Bobby's comments about rotifers inspired me one more time to try
to find an article I had seen called "Daphnia by the pound".  I think the
article was somewhere in the house, but where.  Searches on the net revealed
nothing.
    Just two days ago, I heard about a search engine called dogpile.
Searched google for dogpile, found it, entered      daphnia by the pound.
The 13th hit was it!!!!  Found it again.  Since the article was reprinted, I
figure we can reprint it here.

George Davis
Wilmington, De

DAPHNIA BY THE POUND


by Milward Lavin


We are reprinting this article from the June 1931 issue of Aquatic Life
magazine. Although it is 65 years old, it's still the best information
available on the subject.

  In the past, much ridiculous nonsense has been written about the raising
of daphnia. In most cases it has only resulted in failure. Everything has
been tried from banana skins to dead cats and dogs. With such methods all
that can be raised is a big stink and nothing more.
  To raise daphnia you have to know what you are doing and it all comes to
one point. That point is common sense.
  First, "the way to any animal's heart is through its stomach." Daphnia
must eat to live and Nature did not make daphnia so they could eat
everything. Daphnia will eat nothing but infusoria and I know what I am
talking about when I say infusoria.
  Daphnia must have clean water with lots of oxygen, supplied by plant life
or compressed air. Either one will do. They must eat to exist, so it's up to
you to supply the food which is infusoria. Infusoria cannot be raised with
the daphnia in tubs, as it is in ponds. You will have to raise the infusoria
separately in another tub.
  To raise infusoria we again come back to the law of nature which is the
way to any animal's heart is "through its stomach." All living things must
eat to exist. Infusoria will eat only what mother nature intends for them to
eat, and that is bacteria. Any kind of bacteria will do, but it must be
bacteria.
  We now find that it is necessary to raise bacteria. Now that we know the
starting point, let us go at it in a systematic way. The system I am about
to explain is the one used in all medical institutions to raise any kind of
bacteria. It is the correct method and exceeds all others.
  Make a bacteria culture medium according to the following formula:

Water . . . . . . . . . . . . . . . . . 1 gallon
Beef bouillon cubes . . . . . 5 cubes

or

Water . . . . . . . . . . . . . . . . . 1 gallon
Extract of beef . . . . . . . . . 5 level teaspoons

  Either formula will do. Boil for five minutes. Then allow to cool. After
the solution is cool, dissolve in it one level teaspoon of lye. (Sodium
Hydroxide). Be sure to use only a level teaspoon. This solution will start
bacteria growing in it and in a month's time it will be in wonderful
condition. Keep the solution open and uncovered because all bacteria first
comes out of the air to begin with.
  They multiply better and faster in the solution than they do in the air.
Replace whatever water evaporates up to the time you begin to use the
solution, but not after you begin to use it. Keep the solution in a dark
place. Bacteria grow better in the dark. They can grow at a temperature of
65 to 75 degrees, but they grow best at 98 degrees F., which is the
temperature of blood. A dark corner in a warm boiler room is ideal.
  In three weeks to a month you will see a scum on the surface. This scum is
infusoria. Now, fill a tub with water and let it stand overnight to get it
to room temperature. Then, take a small net made of bolting silk and skim
off the infusoria and place them in a second tub. Here they will multiply
much more rapidly because the water is cleaner.
  Every two days take a tumblerful of bacteria solution and pour it into the
infusoria tub so the bacteria can eat. The infusoria will do fine on it.
Keep the tub uncovered and in the light at room temperature. Soon you will
have your tub just swarming with infusoria. Throw some water plants or water
weed in this tub. They will keep the water fresh with their oxygen.
  Now for your daphnia. Get another tub. A big one. Fill it with water and a
good many water plants or water weeds to supply the necessary oxygen unless
you have compressed air to supply the oxygen. Daphnia need a lot of oxygen.
Place a few daphnia in the tub. Every two days take your little silk net and
skim off the infusoria and feed it to the daphnia. Very soon you will have
daphnia by the pound. But don't forget and run out of bacteria solution.
When the bacteria solution is half used up, start making another gallon. If
you run out of bacteria solution you won't have anything to feed to the
infusoria. The infusoria will starve to death before you can get the second
lot of bacteria ready as it takes a month to breed the bacteria.
Don't make more than one gallon of bacteria solution at one time and it
should never be more than two months old at the most, for it can get so old
as to be useless. A glass of bacteria solution from the first lot will help
to start the second lot of bacteria. Remember - it must be done in three
parts.

1. Your bacteria solution
2. Your infusoria solution.
3. Your daphnia solution.

You cannot combine any two or three solutions. If you do, all will fail,
because bacteria want putrid beef solution, heat and darkness, infusoria
want clean water, light, and a chance to breed, while daphnia want clean
water and plenty of oxygen which the plants supply. It is all just common
sense.

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