Daphnia?

[r.c.]

I've been trying to start a daphnia culture from pond collected daphnia. I've never had such a culture before, and as it's so cold this time of year I thought I might have to wait until spring.

Instead, I got about a gallon of pond water from my backyard and put it in a 10 gallon aquarium. I've got a dozen or so mayfly larva, and using a turkey baster I was able to isolate around 20 or 30 of things which are about the size of spider mites, some a bit bigger.

Some of them are light brown/reddish, some are darker, almost black. Some of the black ones have what appears to be eggsacks indicative of copepods. All of them are moving with very jerky motions through the water.

My question is how to (without a magnifying glass) tell if there are any daphnia in there, or if it's all copepods. Just wait?

I put the 30 or so in a cup to keep them away from anything in the aquarium that would eat them, and will keep looking for more. Eventually, I would probably just toss the water (it's dirty, I'd like it to look cleaner) and put the critters back in the tank with some yeast.

I've heard bad things about copepods from some, so I'd rather be culturing brachiopods. I don't mind if a few sneak in, but I would rather not have all copepods.

Do I need to wait until next year? Maybe take another sample and hope for some better luck? I tried dragging a brine shrimp net around a little and got pretty much nothing except really cold feet. Maybe I didn't do it long enough...

 

[r.c.]

One more thing... About my failed collection attempts. I have a very small pond right behind my house that all kinds of stuff grows in during the summer (dragonflies, etc.) This is where I got the copepod water.

There is another larger pond (probably a 50 yards by 10 yards) where I tried to get things but my net was empty... I swished it along the edge, and then waded in toward the center, for about 5-10 minutes and MIGHT have had a very few small creatures, but I didn't keep them since I was a bit frustrated and not getting a net worth of stuff.

There is a third pond quite a ways back that is probably 100 meter diameter. This has some fish in it, so I was trying to avoid it. It's fed by a slow moving creek which I did try, that turned up empty, too.

Can anyone recommend better techniques? (Or again do I just need to wait until spring?)