Timpanoga hecuba

Mark Melton

Life of the Party
The ones on top are operculae. They protect the gills from the silt and other irritants. The gills are underneath these. You can see a little bit of the gills poking out in the bottom picture.
 

Mark Melton

Life of the Party
Hi Mark-

I sincerely believe you are the most talented aquatic macro-invertebrate photographer on this planet.

Hey Roger,
Thanks for the compliment. You've certainly looked at many photos of macroinvertebrates. However I believe that almost anybody can take good photos of them with the cameras of today.
 

Mark Melton

Life of the Party
They're the operculae {singular-operculum} and gills. The operculum is on top of the gills and made of a horny substance, The gills are underneath, protected from silt and other detritus. The operculae are probably an adaptation due to the nymph almost always sitting on the bottom in slackwater areas such as pools
and the edges of glides.
 

Matt B

RAMONES
Forum Supporter
They're the operculae {singular-operculum} and gills. The operculum is on top of the gills and made of a horny substance, The gills are underneath, protected from silt and other detritus. The operculae are probably an adaptation due to the nymph almost always sitting on the bottom in slackwater areas such as pools
and the edges of glides.
Thanks, sorry to be redundant, just making sure what we are talking about! I was looking for the gills (but still not sure I see them) and was also confused by top/bottom vs dorsal/ventral etc!!

Would the overall “spikeyness“ be to deter predators? And what predator would that be effective on, if so?
 

Mark Melton

Life of the Party
Thanks, sorry to be redundant, just making sure what we are talking about! I was looking for the gills (but still not sure I see them) and was also confused by top/bottom vs dorsal/ventral etc!!

Would the overall “spikeyness“ be to deter predators? And what predator would that be effective on, if so?
I imagine that the "spikeyness" would help to deter predators, along with it's width. In the creek where I found them the primary predators would be Caifornia roach, the fry of steelhead and coho, occasionally a steelhead that stayed over a year, sculpins, and dragonfly larvae. I suppose that the spikeyness would deter naive predators but the nymphs habit of sitting in shallow areas of the stream and being covered with detritus, plus it's natural camouflage would seem to be it's primary defense.
 

Cabezon

Sculpin Enterprises
Forum Supporter
Hi Mark,
Do the operculae move? That is, do they pump water over the gills in such quiet water or simply act as covers against coverage of silt?
Thank you,
Steve
 

Mark Melton

Life of the Party
Hi Mark,
Do the operculae move? That is, do they pump water over the gills in such quiet water or simply act as covers against coverage of silt?
Thank you,
Steve
Steve,
I can't remember. It's been years since I observed them and I couldn't find any in a cursory search of specimens. I would assume they have at least a limited amount of movement. I did find a photo of a nymph covered in debris though.

 
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