Monday, October 10, 2011

The Doyles River Gives Up Some of Its Riches

Is that a gorgeous insect or what?!  Flatheaded mayfly: Maccaffertium vicarium.  It will hatch in March as a "March Brown" -- in fly fishing terms.

I got some stunning photos today, and I won't do a lot in this entry other than post the best of the lot.
Today I went further up on the Doyles River than I normally go, stopping at the bridge where Rt. 810 turns away from the river -- for those of you who travel this way.  The stream is small up here, but the water is crystal clear, clean, rocky and cold.  The dominant taxa today?  Small minnow mayflies, Acentrella turbida, and Giant stoneflies, various sizes.  There were also a few netspinners around, a couple of common stoneflies, some smallish crane fly larvae, and a couple of flatheads -- but nothing else like this little beauty.

You may recall that this is one of the few Maccaffertium species that we can ID without detailed anatomical study.  M. vicarium has dark bands on the back (posterior edge) of the abdominal segments -- both dorsal (terga) and ventral (tergum).  Here's the ventral view.

On to the pictures.

1. More views of the M. vicarium nymph.



And one final picture, where it's giving a small minnow mayfly a ride!

2. Small minnow mayflies (Baetidae), genus and species Acentrella turbida.  All of these photos are of the same nymph, the only one that was mature, and therefore the biggest of the lot.  That's not saying much, since it measured 4mm (about 1/8").  Acentrella turbida nymphs are small, among the smallest small minnow mayflies we see.

Enjoy!  (And be sure to double-click on the photos to enlarge them to get the best views.)

And a a shot showing our small minnow mayfly riding on the back of a Giant stonefly.  It's probably the best "overall" view I got of this tiny nymph.

3.  I did take a photo of one of the common stoneflies that I found.  This one is Acroneuria carolinensis -- still immature, but very colorful with well developed patterns.

Finally, I did one "diagnostic" photo when I got home -- a good shot showing the dense setae on the femora and tibiae of one of the Acentrella turbida nymphs I preserved.  Remember that this "hair" is one of the keys to identification.

But, we have to end with "the catch of the day".  Wow!

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