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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.

Dorsal view of a Grammotaulius betteni (Limnephilidae) (Northern Caddisfly) Caddisfly Larva from the Yakima River in Washington
This is a striking caddis larva with an interesting color pattern on the head. Here are some characteristics I was able to see under the microscope, but could not easily expose for a picture:
- The prosternal horn is present.
- The mandible is clearly toothed, not formed into a uniform scraper blade.
- The seems to be only 2 major setae on the ventral edge of the hind femur.
- Chloride epithelia seem to be absent from the dorsal side of any abdominal segments.
Based on these characteristics and the ones more easily visible from the pictures, this seems to be Grammotaulius. The key's description of the case is spot-on: "Case cylindrical, made of longitudinally arranged sedge or similar leaves," as is the description of the markings on the head, "Dorsum of head light brownish yellow with numerous discrete, small, dark spots." The spot pattern on the head is a very good match to figure 19.312 of Merritt R.W., Cummins, K.W., and Berg, M.B. (2019). The species ID is based on Grammotaulius betteni being the only species of this genus known in Washington state.
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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Jesse's profile picture
Posts: 378
Jesse on Feb 8, 2012February 8th, 2012, 8:41 am EST
So for some time now i have heard about the positive and negative affects that flooding has on spawning trout. On one side of the spectrum (the negative), i have heard that flooding is bad for spawning fish because it covers their eggs and young with much sedimentation. Preventing a successful spawning process. On the other side of the argument (the positive), i have heard and know that flooding waters allows for easier access of trout to smaller, colder, more appropriate spawning tributaries. Also, it allows for easier access to general movements of trout upstream. Its been said that trout, despite high flows, find the perfect water to spawn in anyway. Its a topic that i often hear about when floods come in, but try to stay open for opinions. What do you guys got?
Most of us fish our whole lives..not knowing its not the fish that we are after.
Entoman's profile picture
Northern CA & ID

Posts: 2604
Entoman on Feb 8, 2012February 8th, 2012, 9:15 am EST
It also cleans the redds of accumulated silt which is good for future spawning.
"It's not that I find fishing so important, it's just that I find all other endeavors of Man equally unimportant... And not nearly as much fun!" Robert Traver, Anatomy of a Fisherman
PaulRoberts's profile picture

Posts: 1776
PaulRoberts on Feb 8, 2012February 8th, 2012, 9:22 am EST
It's not an either/or. All the above, and lots more, can be true. Nature doesn't hold back for no one -whether it has scales, feathers, fur, or... neoprene.

Redds are attempted in a range of locations and conditions that surround an "optimum". Those that survive pass it on. Those that don't, don't. And it's not always their fault. In this way populations adjust over time to a range of conditions. Some years virtually entire spawns can fail. Others years it's a boon.
Falsifly's profile picture
Hayward, WI.

Posts: 660
Falsifly on Feb 8, 2012February 8th, 2012, 11:28 am EST
Unless I’m mistaken trout predate our existence and have endured eons of flooding and drought, not to mention extreme global environmental changes. To view natural occurrences as positive or negative is nothing more than an anthropomorphic presumption caught in the myopia of the here and now. Through the eyes of the fisherman it’s a question of how is it going to effect my fishing tomorrow. In the grand scheme of things it is what it is, has always been, and always will be….. ;)

Hey, you asked.
When asked what I just caught that monster on I showed him. He put on his magnifiers and said, "I can't believe they can see that."
PaulRoberts's profile picture

Posts: 1776
PaulRoberts on Feb 8, 2012February 8th, 2012, 11:37 am EST
Mmmmmmmm...no, things have changed drastically. Flooding and drought are much more frequent and intense due to watershed disturbances by human development. This is old news. Widen the scale and we are actually living within a global extinction rate that rivals those in the distant past that literally define the boundaries of major geologic periods.
Oldredbarn's profile picture
Novi, MI

Posts: 2600
Oldredbarn on Feb 9, 2012February 9th, 2012, 4:46 am EST
Allan & Paul...I have yet to have my second cup of tea and find myself this morning still wearing my rose-colored glasses...Go figure? I must of exited the bed on the correct side for a change...I'll get back with you here...

On the not so natural side of it though we have had some problems below some of our dams here with spring spawning smallie's because the despot controlling the lever doesn't want the folk in the man-made lake above the dam ever to have to step up or down an inch to get in to their pontoon party boats...

"Even when my best efforts fail it's a satisfying challenge, and that, after all, is the essence of fly fishing." -Chauncy Lively

"Envy not the man who lives beside the river, but the man the river flows through." Joseph T Heywood
Jesse's profile picture
Posts: 378
Jesse on Feb 10, 2012February 10th, 2012, 10:53 am EST
Good points by all and i understand the adaptation of trout to deal with natures elements. I was more or less wondering on a year to year basis, but i guess is that its neither good nor bad, but a little bit of both.
Most of us fish our whole lives..not knowing its not the fish that we are after.
PaulRoberts's profile picture

Posts: 1776
PaulRoberts on Feb 10, 2012February 10th, 2012, 11:14 am EST
Lots of potential effects, Jesse. Minor flooding/spates are what do the work in streams, creating pools, pockets, etc... -"digging spates" I call them. But I've seen "catastrophic floods" make barren moonscapes out of previously awesome stretches, only to have them re-dug back into trout hotels in subsequent years.

Because of ditching and draining (everywhere a development goes in), many streams are more prone to be "flashy" as water is removed from the surrounding land at a quicker rate, rather than being retained in the land. Habitat too becomes "flashy" -here today, gone tomorrow. Fish populations may adapt, but some level of stability in the system sure helps grow trout.

As you mentioned, flow affects spawning too. Many trout rely on seasonal spates to move into spawning/nursery stretches. But big floods can scour eggs and sweep fry out of nursery water. Each year is different, and you can see where some stability here is made good use of.

In waters with stable flow, trout lead much more stable lives, often living in small home ranges -some even spending their summers in one pool. In flashier streams, trout move like crazy. Summer, fall, and winter create different habitat needs and trout find these, or perish. Trout in many waters may treat an entire watershed like they might a lake -this seems esp so with those big browns.

Individual trout handle high water pretty darn well. And aquatic insects are mobile and fecund and can rebound quickly even after catastrophic floods. One year, we had a nasty flood while I was teaching a FF course. When we went to sample for inverts in a diverse stream (I'd sampled successfully just the previous week), we caught NOTHING! It was scoured clean. So, we had a nice streamside chat about floods, and rescheduled.

Oh...I also wrote an article on high water fishing strategies called "Ain't No River High Enough" in the March/April 2002 American Angler.
Jesse's profile picture
Posts: 378
Jesse on Feb 14, 2012February 14th, 2012, 9:05 pm EST
Do you by any chance have a copy of that article Paul?
Most of us fish our whole lives..not knowing its not the fish that we are after.

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