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More Daphnia, et al




Dan,

Thank you for some great ideas with your daphnia food mix. You mentioned
lecithin as a natural wetting agent. What exactly is it and where does one
purchase it?

Also if one took your blended concoction, pour it into ice cube trays and
filled freezer bags with them, would they retain enough of their nutritive
value to make them worthwhile?

Moon makes a valid point  in that mosquitos do not turn up in an active
daphnia culture very often if the culture is well populated. Daphnia left in
fry tanks to polish off bacteria will develop a pleasant orange when newly
hatched baby brine shrimp are added. Certainly they could inhale the smaller
and softer newly hatched mossie larvae.

However, if the daphnia disappears and no wigglers are present, I would look
after dark to see if a predator is there. We noticed an abrupt decline in a
culture in a 32 gallon trash can lined with composed cattle manure. A check
well after dark showed quite a crowd of 1-2 cm dragonfly larvae which had
crawled out of the bottom mulm and up the sides of the container.

For a couple of evenings we netted a bunch  of them and - one at a time -
dropped them into the tank of a good sized pair of Central American cichlids
who were caring for a nest of fry. Extra dragon flies were frozen.

Still it seemed impossible to get all of the dragon fly larvae out of the
barrel and eventually a hole was dug in the garden, the whole mess was
dumped in and quickly buried. The trash can was hosed down, new manure and
water added, and it was re-seeded with a Daphnia start. (Always keep more
than one of whatever you are trying to culture.)

Our outdoor Daphnia cultures are situated where they get some sun in the
early spring and fall. However leaves shelter them from the summer sun which
surely would overheat them and cause a crash. Sheltered cultures are also
less vulnerable to flying Daphnia predators. If it doesn't reflect sunlight,
fewer flying beasties like water beetles, backswimmers, dragonflies or
damselflies are likely to drop in or lay their eggs there.

> I harvest them everyday and make
> sure I get the pupa before them change. > Moontanman

Also extremely important advice.  :)

All the best!

Scott