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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:
> Chuck 
> 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.
> Gay
> =============================
> Hatching Daphnia ephippia (resting eggs):  
> I have started Daphnia from ephippa (resting eggs).  Easy?  If 
> you've
> hatched fish eggs, I'd say yes.  If you are getting ephippa (resting 
> eggs),
> they will appear in black saddles on the females.  Take enough water 
> from
> the tank to fill a 10 gallon tank with about half an inch of water.  
> Catch
> 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 
> hydrophobic,
> about 1 to 2 mm long and look like specks of pepper, some of which 
> will
> float on the surface of the water and others which will sink to the 
> bottom
> of the culture container.  What is nice is that they will also 
> withstand
> 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 
> exposed
> to too high or too low a temperature, lack of food, over crowding or 
> too
> short a light period.  In these cases some of the Daphnia will 
> become males
> and mate with the females, producing ephippia (resting eggs), which 
> can
> 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 
> others
> 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 
> conditions
> 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 
> for
> about two weeks.  Fill a two to ten gallon aquarium with hard 
> alkaline water
> the same temperature as the temperature in the refrigerator.  Aerate 
> lightly
> and add the ephippa (resting eggs).  Allow the water to reach room
> temperature naturally and slowly.  Once the Daphnia have hatched, 
> aeration
> 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 
> with
> 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 
> and
> lightly aerate.  Usually only a few eggs hatch at an attempt.  This 
> is
> nature's insurance policy that the Daphnia are not wiped out by 
> fickle
> weather.  Each time you repeat these processes, a few more eggs will 
> hatch. 
> 3.	Or another method is consists of nothing more than doing 
> nothing
> 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 
> degrees
> Fahrenheit (22 degrees Celsius) in the presence of good Daphnia 
> water
> parameters water.  The water will green up and often Daphnia will 
> then
> appear as most of the embryos in the ephippia resting in the mulm on 
> the
> bottom will hatch within a 10 days to 2 weeks.  
> The above methods will work for any and all Daphnia cultures be they 
> Daphnia
> magna, Daphnia pulex or Moina.  If they don't appear or you are in a 
> hurry,
> 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
> 
> 	History:  
> 
> 	Last spring, I threw some daphnia magna in a 300 gallon 
> plastic
> rainwater 
> 	pond and was amazed at how prolific and large they became.  
> During
> 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 
> buckets
> of water 
> 	and pond mulm outside just in case they came back (and to 
> grow
> 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
> have 
> 	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
> Midwest.  
> 	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 
> couple
> inches of 
> 	rain which of course may have stirred things up in the 
> buckets.  
> 
> 	Comments about the cycle appreciated.  Do the eggs need to 
> go
> through a 
> 	freeze/thaw cycle before they start hatching again?  Do you 
> think
> 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 
> another
> 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 
> food."
> 	


Robert Rice
All Men are equal until the point of exertion
 http://www.nativefish.org