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Re: NFC: RE: outdoor daphnia magna - they appear to be back
Can I get some starters from someone I have several empty tanks that
would be nice back porch hatcheries...
On Fri, 10 Dec 1999 13:36:32 -0900 "Hemsath, Gay"
<GHemsath at alascom_att.com> writes:
> As can be seen in the text below the Daphnia ephippia (resting eggs)
> do not
> have to be either dried out or froze in order to hatch; although
> they can
> with stand either on or both and still be viable.
> Hatching Daphnia ephippia (resting eggs):
> I have started Daphnia from ephippa (resting eggs). Easy? If
> hatched fish eggs, I'd say yes. If you are getting ephippa (resting
> they will appear in black saddles on the females. Take enough water
> the tank to fill a 10 gallon tank with about half an inch of water.
> out the saddled females and put them in this half inch of water.
> Allow the
> tank to completely evaporate. Wait a few weeks, and then fill the
> tank all
> the way up. > An amazingly tough egg. It can withstand being dried
> out >
> and sun baked, frozen.
> Question is how long can they remain dormant and the eggs still be
> viable ?
> I've read somewhere they can remain viable for years.
> Ephippia are the resting eggs that can withstand freezing and drying
> conditions. They are black, saddle-bag shaped, and pretty
> about 1 to 2 mm long and look like specks of pepper, some of which
> float on the surface of the water and others which will sink to the
> of the culture container. What is nice is that they will also
> sterilizing in a three to five minute bath in 5% Clorox solution,
> which very
> few microorganisms will do. Just rinse them after this and put them
> in some
> aquarium water and place in the refrigerator for about two weeks.
> Fill a
> two to ten gallon aquarium with
> All Daphnia species produce large black ephippia (resting eggs) if
> to too high or too low a temperature, lack of food, over crowding or
> short a light period. In these cases some of the Daphnia will
> become males
> and mate with the females, producing ephippia (resting eggs), which
> resist drying and freezing. The ephippia (resting eggs) look like
> specks of
> pepper, some of which will float on the surface of the water and
> which will sink to the bottom of the culture container. Once this
> starts to
> happen the culture is probably going to die out soon unless
> improve. If you ever have a "crashed" Daphnia culture, DON'T THROW
> IT OUT!
> The hatching of resting eggs ( ephippia) is triggered by an
> abundance of
> food, good water conditions and a lack of adult Daphnia.
> 1. Place the Daphnia ephippia or the "mulm" from the bottom
> of the
> crashed Daphnia culture in a container of water in the refrigerator
> about two weeks. Fill a two to ten gallon aquarium with hard
> alkaline water
> the same temperature as the temperature in the refrigerator. Aerate
> and add the ephippa (resting eggs). Allow the water to reach room
> temperature naturally and slowly. Once the Daphnia have hatched,
> is optional. Tank should be lit with a timed light at least twelve
> hours a
> day, or you can leave the light on 24 hours a day.
> 2. Another hatching method is to place the ephippia resting
> on the
> bottom in the mulm and a little fine peat moss in a ten gallon tank
> less than a half inch of water. Allow the water to slowly
> evaporate. After
> the tank has been dry for at least a week, completely fill the tank
> lightly aerate. Usually only a few eggs hatch at an attempt. This
> nature's insurance policy that the Daphnia are not wiped out by
> weather. Each time you repeat these processes, a few more eggs will
> 3. Or another method is consists of nothing more than doing
> assuming the crashed culture doesn't smell bad. Just leave a light
> on over
> the crashed indoor culture for 24 hours a day, keep it at around 72
> Fahrenheit (22 degrees Celsius) in the presence of good Daphnia
> parameters water. The water will green up and often Daphnia will
> appear as most of the embryos in the ephippia resting in the mulm on
> bottom will hatch within a 10 days to 2 weeks.
> The above methods will work for any and all Daphnia cultures be they
> magna, Daphnia pulex or Moina. If they don't appear or you are in a
> then seed the tank from another culture.
> -----Original Message-----
> From: CEFCHURCH at aol_com [SMTP:CEFCHURCH at aol_com]
> Sent: Friday, December 10, 1999 12:39 PM
> To: nfc at actwin_com
> Subject: NFC: outdoor daphnia magna - they appear to
> be back
> Last spring, I threw some daphnia magna in a 300 gallon
> pond and was amazed at how prolific and large they became.
> the heat
> of August, the culture disappeared. Water temperature at
> the bottom
> of the
> pond climbed to the low 90*'s F.
> Since then, I cleaned the pond out but kept a few 5-gallon
> of water
> and pond mulm outside just in case they came back (and to
> mosquito and
> bloodworm larvae in). I was told that the culture
> would/might come
> back from
> (I assume) dormant eggs once things cooled off. There were
> none in
> there a
> week ago but today much to my surprise, four of the buckets
> seem to
> significant numbers of what appears to be very small daphnia
> swimming around.
> It has been a warm and dry Fall as things normally go here
> in the
> In the last couple weeks, the temperatures have dropped to
> the 20's
> and have
> gotten up to the 60's during the day. Last week, we had a
> inches of
> rain which of course may have stirred things up in the
> Comments about the cycle appreciated. Do the eggs need to
> through a
> freeze/thaw cycle before they start hatching again? Do you
> the couple
> inches of fresh rain had anything to do with it?
> My next step will be to net all the feeder goldfish out of
> 300 gallon
> pond (where the water changed to a wonderful green color)
> and put
> some in
> there. And also bring some indoors.
> Chuck Church
> Indianapolis, Indiana USA
> "Nobody likes Green Water except people who raise live fish
All Men are equal until the point of exertion