Daphnia

Food, feeding and diet.
Colin Whitworth
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Daphnia

Post by Colin Whitworth »

Hi,
I am fed up with paying for live daphnia. I heard it was possible to cultivate your own by putting shredded lettuce leaves in a container out doors. I did this with a large plastic box, left it for a oouple of weeks and introduced daphnia bought from my LFA. Within a ouple o weeks they were gone.
Any advice would be appreiated.

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Gingerlove05
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RE: Daphnia

Post by Gingerlove05 »

@"Vale!" :D
 😇Heaven doesn’t want me...
And Hell is afraid I’ll take over! 😈

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Daphnia

Post by piker »

Probably killed off by a build up of ammonia,daphnia are very sensitive to water quality.
Also the colder weather will kill them off.
I had a successful tank in the garage going for over a year with a cycled air driven sponge filter,temp at 18c and fed with yeast and spirulina powder.lights on 10hrs a day.
Then one day they just died so I gave up.


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RE: Daphnia

Post by Colin Whitworth »

Gingerlove05 wrote: @"Vale!" :D
Thanks for that info. I didn't think to bring them inside. I will try again in the conservatory, with some yeast.

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RE: Daphnia

Post by Vale! »

You rang?  :D  

Daphnia filter food from the surrounding water. Food items are typically 2 microns (2 thousandths of a millimetre) or less in size. So, inter alia, bacteria, yeasts, rotifers and phytoplankton (tiny creatures that need light) are on the menu. 

I'm not sure that a few lettuce leaves would generate enough of this stuff to support an adequate population of Daphnia - and a significant amount would adhere, or remain close to the surfaces of the lettuce leaves and be relatively unavailable.  I say 'relatively' because the combined turbulence of a cloud of Daphnia can dislodge quite a bit of that, but you need a goodly number of Daphnia to start with! 

To do what you're trying, CW, you need ideally either:  to adopt Piker's strategy of making up a feed especially for them ; or have them swimming in a eutrophic environment - i.e. loaded with the nutrients that phytoplankton etc. need.  A really good way to achieve the latter is via a handful of horse sh*t! Garden compost comes a close second. You can get proprietary mixtures that do the same sort of job [see below].  You also need some source of light ; and an airline, both to try to maintain dissolved oxygen concentration (the phytoplankton will use oodles of oxygen!) and to keep food in suspension.  Co-culturing with snails or worms (I can give you some blackworms if you want them) should improve the yield.

When Daphnia suss that conditions are becoming less than ideal they produce ephippia - essentially eggs that are provided with an extra protective coat. So when temperature drops, for example, the adults die but leave behind ephippia which hatch when conditions improve again. 

My Daphnia live in a bath in the garden - I mean literally a bath, as in bathroom! There is no airline, but a favourable surface area to volume ratio ; and the wind and rain increase the surface area, of course.  In high Summer there's a ridiculous amount of Daphnia. For a few months either side of high Summer the population is more than adequate for my needs : I'm still using them now. By December there'll be hardly any ; but in April they'll be back, via their ephippia.  

I used to pass a pile of horse sh*t on my daily commute through the coutryside but now that I'm retired it's more difficult to find locally. Concrete cows don't seem to excrete anything useful. So, as per Piker, I make up a feed by blitzing with a hand blender things like yeast (I favour deactivated yeast but suspect I'm wrong to do so!) and spirulina powder. These don't contain phytoplankton in themselves, so to make sure that there's some in the feed I add some. I/you can add them directly - as in some of the stuff on this page (where you also see 'Micro Algae Grow', alluded-to above) and indirectly  via dry invert feeds which are really very good, such as this stuff. Although marketed as a feed for, rather than a source of phytoplankton etc., some do appear to hatch from it when hydrated. Blitz with a little bit of water first (else the kitchen gets covered in it!) and then dilute further with tankwater, dechlorinated tap or RO. In high Summer I add about three tablespoons of such a mix to my bath (around 400 litres?) ; and progressively less as the weather gradually accounts for the adult Daphnia.

Up until this year I had been bringing some Daphnia indoors to over-Winter and to provide an occasional feed for fish (I also have/had Moina, which are similar things but more nutritious. see below).  The populations would regularly 'collapse', which is why it's generally a good idea to have more than one culture at a time on the go. I never quite worked out why at the time, but I believe I may have come across something very recently which might, possibly and partially, explain at least some of the collapses. A forthcoming update to my "Dero Dero Dear" thread will be about that in the main.



@"piker" : Most of my indoor invert cultures lived on my racking, in nano tanks. However I'm in the process of revamping the racking, so they've all been moved. My Moina cultures were given to fish (and some went into the bath) because I had nowhere suitable that I could put them without attracting the attention of local divorce lawyers. But I'm planning to start them up again - in my garage!  I know that their air supply will have to be filtered through activated carbon before reaching the tank, and I'll have to insulate really, really well but other than that, any further detail that you can remember to help me plan would be very much appreciated, particularly things like volume of water, dimensions of tank and water-change schedules.

A bonus item!  I wonder how long it takes them to organise for this - the article doesn't seem to give an indication.

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RE: Daphnia

Post by mikeyw64 »

dare I ask @"Vale!" what your opinion on freeze dried daphnia is :)

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RE: Daphnia

Post by Colin Whitworth »

Thankyou Vale for your brilliant reply. Not only very informative but amusing. I will re-read it a couple of times and try some of your suggestions. I am not sure how much equipment I will get so will deal with your simplest points first.
The info about the eggs is great.

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RE: Daphnia

Post by Nick Jarvis »

I have a giant bit of 500mm pipe cut to 4ft and with a bottom welded on that I just left in my garden.
Anyway, 6 months later it was full of daphnia and mosquito larvae among others stuff like copipods.
I just take a little net full every week or so and feed to my fish.
There is loads of leaf debris at the bottom keeping them fed and they just appeared out of nowhere.
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https://www.aquariumforums.co.uk/showth ... p?tid=1765

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RE: Daphnia

Post by piker »

Vale! wrote: … 

@"piker" : Most of my indoor invert cultures lived on my racking, in nano tanks. However I'm in the process of revamping the racking, so they've all been moved. My Moina cultures were given to fish (and some went into the bath) because I had nowhere suitable that I could put them without attracting the attention of local divorce lawyers. But I'm planning to start them up again - in my garage!  I know that their air supply will have to be filtered through activated carbon before reaching the tank, and I'll have to insulate really, really well but other than that, any further detail that you can remember to help me plan would be very much appreciated, particularly things like volume of water, dimensions of tank and water-change schedules.
Just looked through my pictures and can't find any[emoji36].
The tank was a 2ftx1ftx1ft with single t5 tube.Running a single sponge filter.200w heater set at 18c.
To start the tank I dumped a bucket of water change water in that i had cleaned the big tanks filter in,gunk and all.This was left to settle then the cycled sponge filter added and daphnia the week after.
The tank was totally enclosed with 2inch polystyrene sheets to keep the temp in and running costs down.
Water change was 50% weekly with the water change water from my community tank.
I know your up to speed on feeding them vale but my methods were a spirulina/yeast mix to cloud the water.
When the water cleared I would repeat.I also had 2 bottles of water change water from my community tank sat in the conservatory producing green water,this was used when it was available,the colony grew quicker and was by far the best feed in my experience.
Like I said in my last post the tank crashed overnight for no obvious reason and the glass was cut up and made into my custom shrimp tank.

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RE: Daphnia

Post by Vale! »

@"mikeyw64" : The jury seems to be out on whether or not freeze-drying significantly reduces nutritional value compared with just freezing. It seems probable that at least some proteins (maybe enzymes etc.) and/or vitamins may be destroyed, but that could be dependent upon how the food is prepared for freeze-drying!

There's a discussion here which is worth a gander, maybe.

Live foods have a couple of advantages that freeze-dried and frozen foods don't : they can trigger a fish's 'hunting' instinct (which must be a healthy thing to have happen) ; and they can be gut-loaded.  Stuff, such as garlic or vitamins, can be added to the liquid used to rehydrate freeze-dried food and some will soak into it, I imagine. I don't think that could happen to quite the same degree with frozen food.  I don't really know what else to say! If I think of something I'll pipe up.



@"Nick Jarvis" : that sounds great! Is the pipe rusty? (I'm assuming 'welded' means meatal-welded rather than plastic-welded!). Have you a pic we could see?  I'd love to have a look at what's living at the very bottom of the pipe (reduced light, oxygen) but I guess that would be somewhat difficult to arrange!  Does it freeze completely in Winter, so far as you're able to tell? 


@"piker" : thanks for those comments. I'm trying my best not to over-elaborate my plans, but I do want to try generating algae separately but in the same tank (if you see what I mean!). To feed Moina properly two types of algae are necessary, apparently. I used Nannochloropsis and Chlorella before, keeping them in flower vases, but I had great difficulty in keeping contaminants out and eventually gave up and reverted to food of the kind you describe. It included the water used to wash rice, which seemed to work reasonably well. I'm hoping this time that I may be able to culture both together, in a compartment adjacent to the Moina cultures.  Anyway - I don't want to clutter this threads with all that! What roughly was the range of temperatures in the garage that the insulation had to deal with?  Mine can range from near-freezing in Winter to boiling hot in the Summer because the garage door faces the afternoon/setting sun. I'm hoping not to have to have some sort of cooling mechanism!

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