She's Got Etheostoma collis Eyes
#1
Posted 15 February 2016 - 07:29 AM
A couple summers ago Gerald and I had a little sidebar about the usefulness of Carolina Darter eyes as a field identification aid, specifically in regards to distinguishing them from Swamp Darters. We noticed that Carolina Darters' eyes possess a funky "reflective-opaqueness".
I snuck out for a little stream time yesterday, and remembered our conversation after dipnetting a female E. collis.
Roper's Creek (I think), Greenwood Co., SC
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Air temp = 33*F Water temp = 44*F A perfect day for field work.
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The eyes have it.
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A couple pics with some Greenhead Shiners in the same lighting conditions for comparison.
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Ventral spot to verify scaleless breast and E. collis identity.
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Did I mention I had previously shredded my neoprenes?
"No thanks, a third of a gopher would merely arouse my appetite..."
#2
Posted 15 February 2016 - 09:26 AM
#3
Posted 15 February 2016 - 09:59 AM
Sort of a greenish-gray haze on the cornea, similar to black seabass and other fish that are dusk/dawn active. Maybe it has some dim-light vision significance in E. collis, either for feeding at dusk/dawn or in dark spaces under leaf litter?
Gerald Pottern
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Hangin' on the Neuse
"Taxonomy is the diaper used to organize the mess of evolution into discrete packages" - M.Sandel
#4
Posted 15 February 2016 - 12:52 PM
Interesting observation on the eyes. I'm not sure I've ever seen that in darters.
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