Header image
Enter a name
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.

Dorsal view of a Ephemerella mucronata (Ephemerellidae) Mayfly Nymph from the Yakima River in Washington
This is an interesting one. Following the keys in Merritt R.W., Cummins, K.W., and Berg, M.B. (2019) and Jacobus et al. (2014), it keys clearly to Ephemerella. Jacobus et al provide a key to species, but some of the characteristics are tricky to interpret without illustrations. If I didn't make any mistakes, this one keys to Ephemerella mucronata, which has not previously been reported any closer to here than Montana and Alberta. The main character seems to fit well: "Abdominal terga with prominent, paired, subparallel, spiculate ridges." Several illustrations or descriptions of this holarctic species from the US and Europe seem to match, including the body length, tarsal claws and denticles, labial palp, and gill shapes. These sources include including Richard Allen's original description of this species in North America under the now-defunct name E. moffatae in Allen RK (1977) and the figures in this description of the species in Italy.
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.
Troutnut is a project started in 2003 by salmonid ecologist Jason "Troutnut" Neuswanger to help anglers and fly tyers unabashedly embrace the entomological side of the sport. Learn more about Troutnut or support the project for an enhanced experience here.

By Troutnut on June 28th, 2018
I spent a couple hours in the evening fishing the Yakima upstream of the Cle Elum river, where flows were around 265 CFS at the Easton gage. These were pretty good conditions for wading a stretch that looked promising, but there was no sign of decent fish. Most were just salmon parr hitting midges on the surface, and I caught a single small cutthroat.

Photos by Troutnut from the Yakima River in Washington

Yakima River

From the Yakima River in Washington

Quick Reply

Related Discussions

Topic
Replies
Last Reply
18
Apr 5, 2012
by Entoman
5
Aug 8, 2011
by Jmd123
7
Apr 13, 2021
by Adirman
16
Apr 11, 2010
by Walleye
Troutnut.com is copyright © 2004-2024 (email Jason). privacy policy