Is this a Daphnia or a Chydoridae?

[Pat Thielen]

Hey all,

I took this photo just a week or so ago and I had assumed it was a Daphnia, but thanks to a post in another thread I may be quite wrong. I'm thinking it may be a Chydoridae. And to be honest, these guys really look the same to me. Is there any easy ways to tell them apart? I suppose there is a key somewhere online that could help. I did look at several photos of Daphnia and Chydoridae and while some seem quite different others look rather similar.

Thanks!

[Pat Thielen]

Thanks to 75RR I have a key; I'm thinking this is a Chydoridae. Does this sound accurate to you all?

[KurtM]

Yep - see my comments on the other thread.

Cladocerae are interesting enough to become a favorite for some microscopists, just as, say, diatoms or botany or histology or entomology, etc., etc. There are lots of genus and species to dive into if so inclined, and specimens are as easy to procure as a dip of pond water taken from local creeks, lakes, ponds, etc.

As with most everything else, some are easy to ID, others take a bit of doing, and still others get into the fine points. Some are rare, most more or less common. Getting good images and/or making permanent slides can be fascinating for some.

Cladocera, like Copepods, make very interesting studies under crossed polarizers, which make musculature and other features pop out.

Fun stuff!

[Pat Thielen]

I thought I'd post the dark field image of this guy as well.

[billbillt]

Hi Pat,

Great dark field image... thanks for sharing..

BillT