Unknown invertebrate!

Unknown invertebrate!

Observation - Unknown invertebrate! - UK and Ireland. Description: Hi! I'm hoping someone can identify this for me (despite the dreadful picture!). I have had a tank of filtered pond water indoors for just over a week (prior to starting an experiment soon) and it is now full of these little chaps/chappesses. They a

Hi!

I'm hoping someone can identify this for me (despite the dreadful picture!).

I have had a tank of filtered pond water indoors for just over a week (prior to starting an experiment soon) and it is now full of these little chaps/chappesses. They are <2mm long and flit about very fast, like water fleas. In fact, I think it's a Daphnia but I can't be sure.

I have been unable to identify it and hope someone can help!

Many thanks,
Juli