Wednesday, August 22, 2012
Drunella doddsi, Calineuria californica -- and more: The Salmon River near Mt. Hood
On Sunday, 8/19, my son-in-law to be (the wedding's on Saturday) took me fishing on the Salmon River in Welches, OR. The scenery was spectacular, and the water was gin clear and freezing cold -- but the fish that we caught were small. So, I decided to see what I could find under the rocks. Lots of spiny crawlers and lots of small minnow mayflies, with the occasional common stonefly and common netspinner.
1. The colorful nymph in the photo above is a spiny crawler mayfly -- Drunella doddsi. I've only seen them in the northwest, where they're apparently fairly common: they hatch as Red Quills. The body is flattened, and the abdomen -- as in the photo above -- is yellowish brown. This particular nymph was extremely tiny: I'm happy that I was able to pick it up and keep it intact. Another photo:
And yet a third photo, in which you can see an even smaller D. doddsi nymph next to an average common netspinner. (Can't say I actually saw this nymph when I was taking this picture.)
2. The "common netspinner" (Hydropsychidae) in the photo above is one that I can't identify with any precision until I get home where I'll have the use of my microscope. I've noted the "gular suture" in this photo since that may be a key to genus ID: it appears to be fairly rectangular, an indication that it may be a Parapsyche, the same netspinner genus I found out here in the fall (see the post of 11/4/11). But, I don't want to push that until I can work on the ID in greater detail. Here's a better view of the larva.
3. The common stonefly (Perlidae), Calineuria californica. This is a new one for me.
If you look back to my post of 11/4/11, you'll see that I found a stonefly in a small stream close to Mt. Hood that I identified as Doroneuria in terms of the genus. I thought that this nymph might be the same. Very important to that ID is the lack of anal gills and the fact that the setal row at the back of the head (occiput) is "laterally interrupted." Have a look at the head of our nymph: there is indeed a gap between the setae at the sides of the head and the dark line of setae right in the middle.
But I was bothered by the fact that the lateral (rear) ocelli are surrounded by a large yellow oval. So, I decided to look into this further. In my search for more information, I found an important article that is available on-line: the authors are Bill P. Stark and Arclen R. Gaufin, and it's entitled "The Species of Calineuria and Doroneuria (The Great Basin Naturalist, 34:2, June, 1974). In describing Calineuria californica they note -- "head with distinctive large yellow spot covering ocellar area." Bingo. Then I looked up Calineuria californica on Troutnut.com where Jason Neuswanger notes that "their lateral ocelli (simple eyes) in a pale background, separates them from Doroneuria." (http://www.troutnut.com/hatch/1050/Stonefly-Calineuria-californica-Golden-Stone).
Neuswanger notes further that "Calineuria californica is the largest western species of the Perlidae family, with female adults approaching 40 mm in some locales. This species is perhaps better known by anglers under its former scientific name, Acroneuria californica. It is the primary Golden Stonefly hatch of the West Coast states."
The Golden Stones have already hatched here in the West, but, the nymph that I found is clearly immature: it will be maturing over the winter and hatching next year.
4. Spiny Crawler mayfly, Ephemerella dorothea infrequens.
I may revise this identification once I've been able to examine my specimens closely -- but this is a species we'd expect to see in Western streams at the moment. For fly fishermen, this is the well-known mayfly, the Pale Morning Dun (PMD).
There was no doubt in my mind of the Ephemerella identification, so for species identification, I looked at the "Mayflies of the Northwest" mentioned in my last entry. There, on E. dorothea infrequens, we find: "Body uniform brown color, abdomen w/weak, light markings; no abdominal tubercles." There are other features noted on this ID that I need to check when I get home, but the colors seem right, and I cannot see any tubercles on the abdomens of these nymphs.
This will have to do it for posts from the Northwest. Wedding arrangements will be taking up the rest of my time. Back to work in VA next week.