Isonychia velma

Mark Melton

Active Member
This species is found in California and Oregon but not in Washington as far as I can determine. It would be interesting if it were found in Washington. If anyone has seen it please let me know. The nymphs show up in late summer and early fall. The adults usually show in September and October. They're found in fast water or the slower edges of fast water. Size ranges from 10-22 mm for the nymphs in the photos and 22mm for the adult (excluding cerci and antennae).

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tallguy

Active Member
I caught nice fish on an isonchyia pattern on the Pit R. in CA in the fall. The patterns used there are all much darker than you show here, a blackish purple if I recall correctly. We're the pictures above something raised in a light tank? Adaptive coloring? They are good swimmers
 

Mark Melton

Active Member
I caught nice fish on an isonchyia pattern on the Pit R. in CA in the fall. The patterns used there are all much darker than you show here, a blackish purple if I recall correctly. We're the pictures above something raised in a light tank? Adaptive coloring? They are good swimmers
No, they're a natural color for the Russian River in California. They tend to start a light color and then go to a dark green or brown here but I've heard from several sources that they tend to be much darker in the Pit River. Could be another variant or species in the Pit. As far as I know very little work has been done on Isonychia in California. There could well be more than the one species. And yeah, they're great swimmers, better than than a lot of minnows.
 

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