[mistergreen]

I did a little more reading on Daphnia Magna. Did not know that they are sensitive to K, Mg, P and some other salts we regularly put in our planted tank.. I hope this will work out for me. The Floating plants should soak up the excess nutrients.

 

[hydrophyte]

Hey what are you raising them for?

 

[Wasserpest]

Let us know how it works out. I am planning to use one of my garage holding tanks to rear daphnia, or cyclops, or whatever will grow in there. :hihi:

What are you going to feed them? I heard bakers yeast is an option.

Some of these crustaceans do very well in fertilizer loaded ponds (drainage collection ponds in fields etc) so they can handle salts and stuff well. Maybe D. magna is a bit of an exception.

 

[invert1]

Daphnia are super easy. One really cheap feeding method is to get Spirulina from the health food store. I say cheap because like 1 oz lasted me ~9 months on a 10G tank of daphnia, so even though the spirulina is expensive itself it's great to feed them right before you feed the daphnia to your fish b/c then you're also providing color-enhancement in the daphnia.

Also, w/ the spirulina once you get the hang of it, it's a lot easier to make sure you don't overfeed b/c unlike the baker's yeast it's a very clear gradation of color btwn too little and too much.

Also, I'd say if you can find Daphnia magna locally, those are the best species to raise b/c babies can be fed to small fry while the adults are both large and exciting prey for small/med fish and a good vehicle for nutritious food (the spirulina) in significant quantities.

 

[mistergreen]

Hey what are you raising them for?

they're food for the fishies.

Here's where I got info on d. magna.
http://www.caudata.org/daphnia/

Daphnia living in dirty water or nutrient rich water is a myth. They're often used to test water quality. They'll eat floating algae, bacteria, fungi, and to a lesser extent small vegetable matter (soy, rice flour). The trick is to feed daily but not over feeding. Ammonia, low O2 , chlorine, heavy metals, and high salts will wipe them out. So, I'm thinking floating plants are great buffers.

 

[mistergreen]

I got the daphnia through the mail today from here http://www.aquaculturestore.com. Nice place to get native fish too btw..

Holy cow, d. magna are huge!
I'll admit, it was a little expensive but the culture is clean and healthy. And I don't have to deal with jerks on aquabid.

 

[bulrush]

I've tried daphnia before. Daphnia are filter feeders. They are unable to pursue food particles because they randomly "jerk" around, and so many food particles must be floating in the water for them to bump into. They will not do well in still water or tanks with right angles, which is why it is common to use a round trash barrel (clean, 4g or bigger) to raise them, and keep water slowly moving in it.

 

[SearunSimpson]

I've written many times on this forum about the rearing and harvesting of daphnia on a hobby sized scale, and one thing I will mention again, is that daphnia are a great food for gut-loading. You can feed your daphnia spirulina, paprika, yeast, and if you can find it, organic dehydrated vegetable powder (pretty much, powdered V8 juice or the sort).

One thing I do suggest though, is that you pre-mix your powders in a little cup of water, or an old yoghurt container and then pour it evenly around the tank, SLOWLY using your hand or something to slightly 'mix' the water so that it gets evenly distributed throughout the water column.

It is VERY easy to overfeed daphnia, and if you've never kept them, don't be surprised if you accidently kill them all off. They seam to almost peak in population in their given body of water and then there seams to be a huge die-off. To prevent this, collect/cull your population frequently. Not all the way down to nothing, but at least once a week take a good sized scoop out and feed them to your fish.

Also, for this reason, it is also HIGHLY recommended that you keep two cultures going, in case one does happen to die off.

Other than that, they are ridics easy to keep and culture. Just do water changes with old aquarium water, and have slight aeration.

NOTE: slight areation does not mean a filter. It means an airstone set so that it bubbles with big bubbles and goes 'glop..........glop.........glop'. DO NOT have your airstone fizzing. The tiny bubbles can get caught up under the carapace, causing the daphnia to get trapped at the surface.

But since you said you'll have those wysteria or whatever, then you might not even need an airstone anyways.

 

[mistergreen]

things are going well. I have no airstone..
My food mixture is made up of spirulina, gluten free flour (a bunch of legumes), and a few pinches of yeast. I mix 1/4 a teaspoon of the dry mix in a little jar of tank water before feeding. I tried straight powder in the tank and it doesn't work. They clump mostly.

The daphnia just started to molt. Hopefully that's a signal for them to start producing eggs and giving birth!


They're pretty fun to watch. They could be the next cool thing to have. I'll start developing S+++ grade daphnia.

Oh, you can't have the floating plants cover the entire tank. They will swim toward light. I like to have all of the floaters to the sides and it's clear in the middle.

 

[mistergreen]

here's a picture of the daphnia when they arrived. Since then, they're taken on a tan color. I guess the food I'm feeding them is giving them that color. You can see this guy's gut.

And I found a few mosquito larvae in the tank. Try to net them out.The big one snagged a baby daphnia or maybe a copepod. Plus I wouldn't want mosquitos in the house. I fed the little sucker to the fish.

 

[mistergreen]

latest pictures... this is 7 days later.

So these pictures cleared up a few things which the naked eye can't. Their color is around their gut. And they're all pregnant! (eggs on their backs) Lets make some clones!

 

[rasbora]

Interesting stuff, I wonder if you'll notice improved color in your fish after feeding with these for a while.

 

[Cmeister]

Keep us posted

 

[mistergreen]

Lots of babies swimming around now. I read they can start producing offsprings within 4 days. I have to say, these guys are pretty fun to raise. I also added a handful of crushed coral in the tank to adjust the ph and calcium.

I'm getting unexpected copepods in with the daphnia culture as well. More food for the fishes.

 

[mistergreen]

Some babies.
These are a few days old. The new borns are half this size.

I was hoping to get pictures developing youngs inside the mother but I got a picture of clear eggs instead.

 

[Cmeister]

lol they look like little pac-men

 

[Twimbo]

How is the water lettuce doing?

I asked about it at the LFS today and they told me they only stock it in summer for ponds, because its very hard to keep indoors. They said they have tried and failed, as has their supplier.

I was thinking about trying water lettuce as a floating plant, but am now reconsidering.

 

[mistergreen]

they're doing good. You need to give it lights and nutrient tis all.
They are pretty big and grow tremendously fast. If you have any other plants in the tank, they might suffer.

you might want frogbit.

 

[mistergreen]

There was a huge explosion of babies today. I'd say the population tripled to 300.

So the very first day I introduced them into the tank (10-15-09) to today (10-28-09) yielded this much.
I hear their population growth is logarithmic. I should be have a harvestable culture in a few weeks.