1. This is unfortunately the only photo I got before it "darted" away. I believe that it is Fantail Darter, but am not confident enough to rule out Stripetail. It looks like it has a pigmented base to the spinous dorsal fin, but I'm not entirely sure it's just the quality of the photo. It also looks like it has a more pointed snout (which, from what I've read, "points" towards Fantail).
2. Everything seems perfect for Tennessee Darter (and a gorgeous one at that!), but it appears to me missing the red spot at the front of the spinous dorsal fin. I saw two or three females right in the same area with very distinct red spots. Is this just a poorly marked individual? Also, I'm curious about the taxonomy of these guys. Peterson has them split from Tennessee Snubnose but the Fishes of Tennessee doesn't, is this just because Peterson is newer?
3. I'm hoping this is a Bluebreast Darter. I put in a lot of time working on this one. I went with Bluebreast because it has a relatively unmarked cheek except for the dark post-orbital spot (ruling out Redline). In the second dorsal and anal fin, there are dark marginal and pale submarginal bands.
4 and 5. On the walk back to the field station I checked out a tiny stream that runs in to the Little Pigeon River. The water was really murky making it difficult to get a good look at the fish. I initially thought these were Creek Chubs, but then I noticed that they were lacking the black spot at the front of the dorsal fin. So I'm defaulting on Blacknose Dace, but I don't really know why. I wish I got a better profile to see the mouth shape. Also, the Saffron Shiner in the background of 5 is unusually pot-bellied, is this a pregnant female?
Thanks again for all the help you have already provided!