Can you guess what this is?

[gekko]

[zzffnn]

Mite?

[rnabholz]

I'll say Nauplius.

[zzffnn]

I'll say Nauplius.

I could not decide between the two. Probably more likely a copepod nauplius, based on the overall shape. It is more round that a typical nauplius, but more slender than a typical mite.

[gekko]

zzffnn nailed it! Amazing. And Rod came pretty close. I really didn't expect it to be solved so quickly. Thank you both for your guesses.

[zzffnn]

Very nice photo, by the way.

Was that shot with pol? I have not seen it with so much green.

I think the winner should be Rod - he was just too lazy to type "Copepod". I was still not sure (between mite vs Copepod nauplius), when I typed my previous post.

Rod's guess reminded me that nauplius' diet likely have more green stuff than mite. It that green color was caused by food particles (it could be just muscle fiber too). Also the shape is slightly closer to nauplius.

[gekko]

zzffnn, I meant to say that your first guess, mite, was correct, but I agree that, by shape, it could have been a copepod nauplius. Yes, this was in polarized light. I don't know what causes the birefringence: I'll post a brightfield image also, maybe you can identify them.

[zzffnn]

Sorry for the confusion
The upsidedown position may change the shape slightly.
That green color seems to come from muscle fiber and/or exoskeleton. I am just guessing though.

[gekko]

The upsidedown position may change the shape slightly.
That green color seems to come from muscle fiber and/or exoskeleton. I am just guessing though.

Yes, and perhaps also due to pressure by the cover glass. Your guess about the color is interesting. I have posted this in the Images section along with a BF image that may give you a clearer idea? viewtopic.php?f=6&t=3067
Thanks for the discussion.