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3. Epeorus

and a pair

I don't think it's E. vitreus. I know you can't see it in the original photo but gill 1 is not right for E. vitreus. The anterior portion is elongated.



but i will defer to the experts. Another example of why making identifications from photos that do not show all the characters needed to make a positive identification is risky business.

The head capsules can tell a lot sometimes. I was leaning towards E. pleuralis (Gordon Quill) and definitely felt it was at least in the species group. E. vitreus (Yellow Quill) is in a different group and its head is slightly conical at the anterior with the the corners less rounded. The lateral margins are less angled inward as well, so the eyes don't crowd the posterolateral margins or even overlap them as in the pleuralis group. It's also lacking the three bars anteriorly as is typical of vitreus but does show the indistinct V shaped mark of pleuralis.

The gill confirms the species group and also precludes fragilis (the other species in the group known for PA). It's the lack of a dark sclerotized strip running through it. I think it's safe to say it's pleuralis. Unless of course, I'm wrong.:)

Perhaps the best example of the heart shaped femoral marks I've seen on a nymph. Great shots and posing, Eric. I hope you don't get sick of hearing it because you will... A lot! It seems a little prepubescent bonding is going on there. Is it possible that Epeorus species arrange the marriages of their children?;)

That's what I keyed it out to Kurt. Maybe just recently molted?

Yep, that's what I think. It could be the substrate or possibly even the instar stage, I suppose. Perhaps even a little of all three.:) The one on the left sure is heavily maculated for an Epeorus. It also looks like it has eyes on the pronotum as well. How weird is that? Speaking of instars, what size are they? their proportions look like they have a way to go.

Live heptageniid photos sure are nice to work with... The dead ones usually drop their heads and make it a lot tougher. Again, great job.

They both came from the same riffle t the same time. The lighter colored one is about 7.5 mm.