Daphnia

[abrogard]

Anyone happen to know where I can find some water Daphnia (water fleas) in South Aus ?

Should be able to skim them from freshwater lakes, ponds, rivers I'm told but I've not been able to do so. The River Murray doesn't seem to have any (is it dead?).

[Quenda]

Sorry, can't help you at all...but...I would like to know why you want water fleas.

[abrogard]

If you've got a pond it'll get green with algae, which is good. But if you've got fish in there you might like it a bit clearer, to admire your fish. The Daphnia eat the algae, which is good. Gets clearer. The fish eat the Daphnia. Which is also good.

The plants (here we are back at gardenexpress) keep the water healthy by eating the nitrates produced by the fish.

The whole thing provides a wonderful (by sounds of it, not there yet) micro environment to show the kids some natural science and microscopy.

That's what it's all about.

[Quenda]

The whole thing provides a wonderful (by sounds of it, not there yet) micro environment to show the kids some natural science and microscopy.

Yes...an excellent idea for the kids.

No green algae here...

[BenConnah]

Daphnia proves beneficial to maintain pond ecosystem. Fish eat Daphnia and Daphnia eat algae, a balanced life cycle.

[abrogard]

Yep. Trouble is getting it all to happen in an acquarium - or, in my case, a bathtub.

Can't happen because the fish will eat all the Daphnia.

That's why I want some. To breed some. And throw a batch into the acquarium from time to time. Still haven't got there. I have a microscope now and I'm saving buckets of water from different places and testing from time to time and hoping to find/create a colony.

Interesting thing though: my 'pond' was green, majorly green, pea green like green soup.. and now it is crystal clear this last few months. Don't know why.

And: I had a lovely bucket of green scum. Or bucket of water with thick green scum on top. I dipped into it for a sample with container contaminated from having been in a different bucket and overnight the green disappeared....

[Keo]

How do you breed them? P.S. I admire your efforts at creating a healthy ecosystem even if I can't personally see it working out.

[abrogard]

Good page here: http://www.discushatchery.com/raisingdaphnia.html

You can't see it working out? Why not?

[Keo]

Well for starters I hadn't read your link that's certainly not what I was thinking you were going to try. I guess if your willing to make a setup like that and run it just right then I guess there's no reason why not. At the very least it certainly looks like an awesome project to get your kids involved with. I'd love to see photos of how it comes along.

[Enjru]

Back in the early days when I first began keeping goldfish, I used to collect daphnia from dams which friends had built on their farms in rural areas. Then, one time, I noticed a water louse swimming inside the bucket which I was using to transport the daphnia back to my home, and it occurred to me that it would be very, very easy to introduce pests and pathogens from one freshwater environment (ie, dams, natural ponds and waterways, etc) into another (your fishtank or your fishpond). So, I stopped collecting Daphnia from the wild after that. If you were going to actually grow your own Daphnia in a pond, tank or tub (which is separate to where you keep your fish), that would be a wonderful idea. Many simple (but still effective) large goldfish/koi pond designs have a "settling tank" as a pre-filtration area, where the heavier pond water sediment/sludge is allowed to settle and can be drained out every week or so, while the rest of the cleaner water goes through the main filtration system (so that the filtration system does not clog up too easily), and if your pond water is green enough, this would be a great place to grow your own Daphnia. As an added bonus, when there is enough Daphnia flourishing inside this settlement tank, you can even put your baby fish fry into it so they can gobble up the Daphnia and put on an incredible spurt of growth.

[abrogard]

Well that's the kind of thing I'm thinking of. Essentially separate the daphnia pond from the main pond is the idea, so's the fish don't eat all the daphnia - then I dip some out when I want to.

But I haven't got there yet because I haven't got any daphnia yet. I have five buckets of water been there for months and I'm about due to check them again. I use a microscope, take some samples in and have a look. Shouldn't need it though according to what I read. Daphnia grow to about 1 millimetre it seems. Easily seeable you'd think.

I'm thinking to periodically pump some 'pond' (i.e. bathtub) water into the daphnia receptacle and periodically pump or more probably dip (because apparently daphnia aren't too fond of moving water and I guess pump currents might not be good?) daphnia back into the tub.

But now it begins to look like maybe my tub water isn't good daphnia food. My circulatory system, primitive as it is, seems to have struck some kind of balance and the water is now crystal clear - but not from any kind of 'death' because the plants and fish are flourishing.

But no algae means no daphnia food doesn't it.

I'll post a couple of pics so's you can see my humble little setup. Excuse the untidyness. And my laziness - I could have lifted off the cat proof screen to make a better pic for you but I just didn't bother.

You see the bucket? Inside it is that plastic 'wool' stuff they pack pillows with. It has been there many months now. Six at least. That black gunk is the bacterial growth I guess that is living off the fouling from the fish and uneaten food.

If it ain't broke don't fix it. So I'm leaving it alone.

[Enjru]

Yup, if your pond water is clear, then there won't be enough food for the Daphnia to grow. Doesn't matter, there's plenty other yummy foody options available for your fishies!

[abrogard]

well the yummy food option they get right now is woolworths goldfish granules.

Fish fry. I'd like to get some. But I think the fish will eat any fry won't they? How do I go about breeding?

And I'd like some guidelines on amounts to feed if you happen to know anything specific. All I find on the web is too vague. Things like 'an amount equal to the fish's eye'.

Teaspoons or grams or something is what I'd like. The fish have been there maybe two years now so they're doing alright but I'd still like more knowledge. They seem to be getting hungrier or maybe just more tame. They see me from two metres away and near come out of the water, mouths agape, to get food from me.

And then they'll do that again later in the day. So I've taken recently to feeding them twice.

[Enjru]

Yup, in the warmer weather, goldfish definitely like to be fed more than once a day, maybe even 4 times a day (but less in quantity each time). They seem to be especially hungry in the morning and in the late afternoon, before sunset. But, in winter, once is enough as their digestion slows down with the colder water temperature.

Instead of live daphnia, I feed them live brine shrimp. There is much less risk of introducing disease via brine shrimp, because brine shrimp live in a salty water environment, while goldfish live in a freshwater environment.

Other live foods include bloodworms, which you may find growing inside your filtration medium. Feeding live bloodworms bought from an aquarium shop is somewhat risky because of the likelihood of bringing in diseases, but this is much more of an issue for fish susceptible to parasitic infections (especially Discus), rather than goldfish.

Of course, one can always feed frozen brine shrimp and frozen bloodworms as well. If choosing frozen bloodworms, get a reputable brand like Hikari which I think irradiates their frozen bloodworms to ensure they are not carrying any live pathogens which may be introduced into your ponds.

Hikari also makes a good variety of dried pelleted goldfish foods. You can vary them with the seasons, feeding "high-growth" pellets (with a higher protein content) in the warmer months, while feeding more easily digestible wheatgerm pellets during the winter months. Pellets which contain spirulina will assist in bringing out the red/orange coloration.

Do not forget you can feed them water plants, including duckweed and water hyacinths (but please be aware that both of these are weeds, which would have you fined, if someone from your council catches you growing it). You can even try to feed them some salad vegetables such as watercress, or even cooking some frozen peas and frozen carrots (finely chopped), and even some cooked sweet potato (finely chopped) or boiled spinach for them to eat.

As an occasional treat (and only in the warmer months), you can feed some high protein seafood treats such as reconstituted (ie, soaked) dried shrimp, reconstituted (ie, soaked) dried shrimp eggs (which you can buy at the specialist Chinese grocers) and even chopped up fresh prawns (with the spiney bits of the shell removed), chopped up mussel meat, chopped up scallop meat, chopped up oyster meat and even rinsed salmon caviar (to get rid of the excess salt) from the fishmarket.

A more controversial treat would be beef heart, and again this should be given only in the warm weather. Be aware that some fishkeepers really disagree quite strongly with this option, because there has been found to be a protein in beef heart that goldfish cannot digest, but it has been my experience that the high protein in beef heart really helps the fancy head growths of certain goldfish varieties like the oranda, the lionhead and the ranchu, to properly develop.

As for amount, just feed what the goldfish will eat within 10 minutes.

Remember that if you are feeding any of these high protein food suggestions, that you will be adding to the nitrogenous load that your filter will have to handle, so do not leave any uneaten bits lying around the bottom of the pond to rot, but please suck out any uneaten remnants after, say, half an hour or so. You will need to do more frequent water changes to keep the nitrate levels low (unless you have gone to the trouble and expense of installing a protein skimmer/foam fractionator).

Hope all this info has not been too much but has been somewhat helpful!

[abrogard]

Not too much at all. I was reading it like reading a good novel, sorry when it finished.

Yep, very helpful. Thanks.