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2. Specimen Discussion
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3. A Cinygmula nymph without protruding mouthparts?

I've never heard of such a thing, yet here it is, unless I'm badly mistaken. The gills and all the other features scream Cinygmula, as does the fact that it was collected with hundreds of other Cinygmula nymphs representing (I think) at least two species.

Anyone know what's going on with the mouth?

sometimes things look a little different before they molt to the subimago (as yours appears prepared to do), but i'm not sure that's the case here. again, maybe I can take a look at the real thing. i'll spend more time with the pictures later; I'll think about it today and possibly check some resources if I get a chance. the id here should be straight forward.

Interesting. I'll be sending this one to you labeled "Odd Cinygmula?"

Hi Luke & Jason,

Well, I don't know what to think. At first glance it looks a lot like the photos we tentatively placed in ramaleyi. The abdomen, gills and tails are clearly Cinygmula. The rest? Not so sure. The ventral shots show that the maxillary palpi are shorter, not held at a weird angle or something. In addition to the palpi "not looking the way they are supposed to", ditto the very thin femora. Also, the eyes lack the concavity or flat surface giving the eyes a more angled look to them as normally associated with this genera. This is definitely something different from what we are used to looking at with this genus.

regards,

Kurt

Just for kicks, Jason, try running it through the recent key to Heptageniidae genera.

Hi Luke -

I tried the link and couldn't gain access to the full key. Is the presence of fibrilliform portions of the gilling no longer required to be Heptagenia?

Kurt

Kurt,

Dialog box 29b, the one that concludes with a determination of Heptagenia, says "gills 7 with fibrils." That doesn't seem any different.

Try clicking on "larva key" at the bottom of the page that comes up from my link.

Hi Jason,
It definitely looks like Cinygmula to me as well, but it is weird that the maxillae seem shorter. Cinygmula is poorly known in the nymphal stage, and it is possible this represents an undescribed one with shorter maxillae. In some of the preserved material I've seen the mouthparts don't always protrude, but I've never been confident in putting a species name on them (or pretty much any Cingymula nymph, for that matter). Also, like Konchu says, when things are getting ready to moult, they get all crazy (I think it happens just to confuse us!). It might be worthwhile getting DNA from this strange critter!

Jeff

Ah! You're right Luke. Thanks for reminding that head capsules of nymphs can change dramatically when close to emergence. Ephemerellid males in particular start to look like something from outerspace. This explains the difference in eye shape. Perhaps expansion of the head capsule or a withering of the mouthparts interiorly is behind the lack of protruding palpi?

Kurt

Not that I'm aware of.