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3. Siphlonuridae

Found a couple of S.xxxx nymphs

I think the first might be S. quebecensis



I'm not sure of the second one????



any suggestions?

Will

Hi Will-

Another possibility might be Siphlonurus phyllis, which I believe to be the only Siphlonurus species other than S. alternatus present in Manitoba.

what was the habitat for each one?

Habitat - silt/clay substrate /turbid large river - 400' wide / both from the same location at the river edge in approx 2' of water on the river side of small clumps of flooded grasses.

We have S.alternatus and S.phyllis listed here , but I get the sense we may have more here than the lists suggest.

I'm probably wrong on the first one . Ventral markings are a thin central dark stripe thinner at segment 1 than 9 - broken fine dark stripe at the outer edges of segments 1-9. approx 11-12mm

Number 2 is approx 14-15 mm with no discenrable marking on the ventral side.

Couple of larger images that may help. Since I like to photography these critters live and they rarely stay motionless some details may be blurred.

http://www.watersidemb.ca/siph/siphfull1a.jpg

and

http://www.watersidemb.ca/siph/siphfull2a.jpg

Will

Will-

Your higher resolution photos both show "abdominal segments above marked with conspicuous branched pattern", and the 1st higher resolution photo shows "a prominent brown spot on each lateral margin midway between base and apex", which is described by Justin & Fannie Leonard on page 77 of their book, Mayflies of Michigan Trout Streams, as being characteristic of Siphlonurus alternatus.

Do you have a ventral photo of the sternite markings you described on the "first" one?

keep in mind that several spp are unknown as nymphs

Roger- I will make some images on Monday of the ventral markings. Not sure if it means anything but over the period I was collecting on that day .Nymph 1 outnumbered nymph 2 by a ratio of approx 6:1

I did notice comparing the two images that nymph image 1 has lateral projections on segment 10 and nymph 2 does not the plot thickens:)

Konchu - I am new to all this but beginning to understand that your statement however frustrating is very true:))

Obviously I have been taking rather portrait/dorsal views of the nymphs I have been finding. It's becoming clear to me ( I bought Merrit and Cummins and have been rummaging around on Famu) that there must be a set views that would serve to document the salient details that would be of more use than simple portraits.

What would constitute a usefull set of nymph stage images ..

Views-

Dorsal
Ventral
Profile
High magnification mouth parts

I know there are sampling protocols are there imaging protocols???

Will

Will-

Please re-read my above post, which I was busy updating at the same time as your made your above post.

Thanks Roger-

Ventral view of Nymph 1 -

http://www.watersidemb.ca/siph/sipventral1a.jpg

Will

Will-

Your ventral view of nymph 1 reveals markings extremely similar to those illustrated for Siphlonurus rapidus on page 79 of Mayflies by Knopp and Cormier.