tiny, translucent footballs

[JohnPaul]

Recently set up a 10g as a cherry shrimp-only tank, water conditions are pretty pristine in there because of the sensitivity of the shrimp.

Anyways, it's been set up about 2 weeks and just in the last couple of days I've noticed some small planaria in there, as well as these translucent, football-shaped creatures. They are very fast, they can swim quite readily through the water column or else they bound around on the substrate with seemingly quite a lot of energy.

Most of them are very tiny (the size of a grain of sand maybe), but one or two seem to be full "adult sized," as the picture shows. The main part of the pic shows one up next to one of those standard hanging metal thermometers, so it gives you a sense of size (maybe a few mm long), with the inset simply being a more focused image of the thing.

Anyone have an ID on it? Thanks in advance!

 

[newfound77951]

My guess is an ostracod....funny, i just ID'ed an ostracod in the SW forums, too. It has a shell and also you can see little feathers or cirri sticking out the top. If that's what it is they are kind of like copepods. If you had any fish in there they would probably gobble them up. I doubt they'll hurt your shrimp but I'm not that familiar with shrimp (except as dinner). I also may be wrong on the ID but it's probably close.

 

[Mosaic]

I agree it's an ostracod, though I sometimes get them mixed up with copepods. They seem to show up when there are no fish to eat them, so I think they're pretty common hitchhikers. I have never had a problem with them and inverts.

That's some good photography, btw.

 

[JohnPaul]

thanks for the replies, and the compliment on the pic. For my aquarium pics I use a Konica Minolta Dimage Z10. It's only 3.2 megapixels (it's over a year, almost two years, old) but the key is it has a 10x *optical* zoom. I find for taking pics of small stuff, like aquarium critters, having a big optical zoom is just about the most important thing to look for in a camera. I'm no photo expert by any stretch of the imagination, but the close-up pics this thing takes are far superior to my 5.1 megapixel, 3x optical zoom Samsung Digimax S500. (Though in all other ways, I love the Samsung camera way more.)