# Pond inverts as culture starter



## idris (23 Oct 2019)

Before I'm extravagant and spend a whole £3.83 on Daphnia to start a live food culture, I thought I'd have a go at harvesting some from our garden pond.

I've just filled a bucket with some pond water (and a little blanket weed, duck weed and general plant detritus) and sat it in the garage. So far I've seen a couple of tiny critters, but  they're too small for me to identify.

1) How likely are there to be Daphnia in the bucket?
2) If there are, will a week be enough to get a harvestable number?
3) As long as there's nothing like nymphs in the Daphnia culture, does it matter if there are any other small critters in the culture?


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## dw1305 (23 Oct 2019)

Hi all, 





idris said:


> 1) How likely are there to be Daphnia in the bucket?


Quite likely. 





idris said:


> 2) If there are, will a week be enough to get a harvestable number?


No, unfortunately not. During the winter production <"slows down to a trickle">.





idris said:


> 3) As long as there's nothing like nymphs in the Daphnia culture, does it matter if there are any other small critters in the culture?


No. 





idris said:


> So far I've seen a couple of tiny critters, but they're too small for me to identify.


Possibly <"_Cyclops_?"> 

Have a look at the way they move. Copepods (like _Cyclops_) move in s series of rapid darts followed by a stop, followed by a dart etc. "Seed shrimps" Ostracods swim around the substrate in a smooth, tumbling manner, often quite quickly and Cladocera (like _Daphnia)_ bounce up and down, often in open water.

If don't mind having some moss as well? I can send you an invertebrate starter pack. I've found that they travel <"pretty well in damp moss">.

cheers Darrel


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## idris (23 Oct 2019)

Thanks Darrel.
It sounds like Cyclopse I've spotted then.

Would a 1L bottle indoors work? (Someone might object to a bucket of fermenting pond water in the kitchen. )

Thanks for the offer too. I'd like to try with what I've got at the moment (I've never got enough projects ) but I might come back to you on that.


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## mort (23 Oct 2019)

I did the same thing but split what I caught into several buckets. I found that different things did slightly better in different buckets so I had a good mixture of critters to feed during the summer (I still see daphnia moving about at the moment but not really enough to bother). One bucket became overrun with seed shrimp but they were still eaten by the fish, just after the nicer food was gone.
This time of year I still harvest mosquito larvae but feed other foods like live brine or microworms that culture easily indoors.


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## tam (23 Oct 2019)

That's kinda of expensive - a bag of daphnia is only £1 in the LFS here?


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## idris (23 Oct 2019)

tam said:


> That's kinda of expensive - a bag of daphnia is only £1 in the LFS here?


Yeah, but that's inc P&P, which if offset against petrol costs for driving to my LFS ....
Either way, it's still extravagant next to a bucket of pond water.


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## dean (24 Oct 2019)

Like anything aquatic the bigger the volume of water the better 
You wont get much at all from a 1litre bottle don’t think it will actually work 

Lots of videos on YouTube about raising daphnia 
I use 100 gallon plastic ponds to do it and it’s still hit and miss sometimes 


Sent from my iPhone using Tapatalk


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## idris (24 Oct 2019)

There's no shortage of folk doing it in jars n Youtube either.
I was only thinking of a 1L bottle on the windowsill as a way to get enough Daphnia to get a bigger culture started. I figure I'll try it (and the bucket, now with heater set to 20c +/-) and see how it goes. Worst case scenario - 15min of my life I'll never get back.


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## idris (7 Nov 2019)

Update - For a couple of weeks I've had a bucket of pond water in the garage with a heater in it set to about 20°c.
Looking at water samples with a borrowed microscope, I'm pretty certain I have Daphnia in there. I haven't got magnification to the levels of most of the photos I've found online, and if I did it would be a royal PITA to see the Daphnia whilst they're alive and moving, nor have I managed to view one from the side, as per online photos, but I'm  still pretty sure they're Daphnia.
I've also got a greater number of more active, smaller critters (maybe 1/10 the size) which, at the magnification I have, look like mobile grains of rice. I guess they're cyclopse.
I've also had a couple of green worm type creatures. I can't I dentify them, but I'm pretty sure they're not Hydra, as they have segmented bodies, appear to have more invet type mouth parts and eyes.

But back to culturing Daphnia ...
I'll have a couple of demijohns in the next couple of days, and and some straw (as per Darrel's suggestion).
1) To seed a culture, is it enough to just put some of the water from the bucket in a demijohn, put it on a shaded windowsill, and provide a food source for the Daphnia?
2) The bucket has aquired a bluish film on the water surface. My first though was that it was bacterial film, but it sounds like it may be (dead) BGA. Should I avoid this going into the Daphnia culture?
3) Having cultured some green water in a 2L drinks bottle to feed the Daphnia, it started to smell quite unpleasant. Am I right in thinking this is the result of anerobic decay and should not be fed to the Daphnia?


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## dw1305 (7 Nov 2019)

Hi all, 





idris said:


> I've found online, and if I did it would be a royal PITA to see the Daphnia whilst they're alive and moving, nor have I managed to view one from the side, as per online photos, but I'm still pretty sure they're Daphnia.


Watch them swimming _Daphnia_ "bounce" up and down. 



idris said:


> at the magnification I have, look like mobile grains of rice.


Ostracods?




idris said:


> I've also had a couple of green worm type creatures


I'm pretty sure they are midge larvae. 





idris said:


> To seed a culture, is it enough to just put some of the water from the bucket in a demijohn, put it on a shaded windowsill, and provide a food source for the Daphnia?


Yes.





idris said:


> put it on a shaded windowsill,


Full sun at this time of year. 





idris said:


> Having cultured some green water in a 2L drinks bottle to feed the Daphnia, it started to smell quite unpleasant. Am I right in thinking this is the result of anerobic decay and should not be fed to the Daphnia?


Is it still green? If it is it should be all right. You have to keep on sub-culturing the "green water". 





idris said:


> The bucket has aquired a bluish film on the water surface. My first though was that it was bacterial film, but it sounds like it may be (dead) BGA. Should I avoid this going into the Daphnia culture?


Just skim it off, it should be fine. 

cheers Darrel


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## MWood (11 Nov 2019)

I've got a population in the water butt, which I also use for water changes. The idea was that they'd act as a bioassay, as well as providing a food source. Always manage to get a few good net-fulls and absolutely zero input from me.


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## dw1305 (11 Nov 2019)

Hi all, 





MWood said:


> The idea was that they'd act as a bioassay, as well as providing a food source.


I'm a long-term <"rain-water user"> and <"those are some of the reasons"> I like them in the water butt.

cheers Darrel


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