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Lateral view of a Female Hexagenia limbata (Ephemeridae) (Hex) Mayfly Dun from the Namekagon River in Wisconsin
Hex Mayflies
Hexagenia limbata

The famous nocturnal Hex hatch of the Midwest (and a few other lucky locations) stirs to the surface mythically large brown trout that only touch streamers for the rest of the year.

27" brown trout, my largest ever. It was the sub-dominant fish in its pool. After this, I hooked the bigger one, but I couldn't land it.
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Hesperoperla pacifica (Golden Stone) Stonefly Nymph Pictures

This monster started to feed within a few minutes of sharing the inspection tray with its victims. This nymph is a voracious predator of small invertebrates and has even been noted for feeding on small fish and salmonid alevins. The niche it fills in fast water is equivalent to the Dragonfly nymphs that inhabit slower water.

Hesperoperla pacifica nymphs are easily distinguished from other western perlids by the presence of anal gills (obfuscated by algae in the tray) in combination with an hour glass shaped pale mark on the front of their heads.

This stonefly was collected from the Lower Yuba River in California on March 22nd, 2013 and added to Troutnut.com by Entoman on April 4th, 2013.


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Hesperoperla pacifica (Golden Stone) Stonefly Nymph Pictures

Collection details
Location: Lower Yuba River, California
Date: March 22nd, 2013
Added to site: April 4th, 2013
Author: Entoman
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