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.

Wbranch
Wbranch's profile picture
York & Starlight PA

Posts: 2635
Wbranch on Apr 14, 2021April 14th, 2021, 2:47 pm EDT
Hi Camphammer,

It's nice to hear from you. Where are you? Since you mention you saw a whitefish I'm assuming you live in the Rocky Mountains. Wyoming, Colorado, Montana am I close? It is possible but highly unlikely that a spring creek entering another clean and larger river would only have one species of fish. Try fishing it, try nymphs and look for any rising fish. If you see some rises maybe they are trout.
Catskill fly fisher for fifty-five years.

Quick Reply

Related Discussions

Topic
Replies
Last Reply
5
Mar 20, 2009
by Martinlf
2
May 16, 2014
by Kschaefer3
3
Mar 17, 2009
by DOS
Troutnut.com is copyright © 2004-2024 (email Jason). privacy policy