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3. Isonychia

Isonychiids are tough for you guys. We've only got one out here to worry about. This specimen has the overall light color of rufa and the leg banding and prominent full length dorsal stripe of some forms of bicolor. The latter is my opinion. They are all so similar in this species group that there aren't any morphological characters (that I'm aware of) reliable enough to tell them apart in the nymph stage. Kondratieff came up with a few provisionally back in the 80's that were largely shot down a few years later by McCafferty. Depending on color and maculation patterns with species so variable (at least in this regard) is shaky diagnostic ground. :)

Ah yeah. But what I take from this photo is that I need to look at some from the streams I fish and maybe incorporate some yellow into the gills on my nymphs.

Do you see many this color? I'm wondering if this could be another example of recent molting.

you know i don't think i do, but that Ameletus nymph had yellow trachea as well, and was collected from the same location. Diet? O2 levels? Neither the Heptageniids nor the Paralept had any yellow. I do see a yellow hue in the stripe sometimes though.