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Are These Silver Shiners?

Started by Guest_fundulus_* , Jun 21 2011 08:24 PM

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18 replies to this topic

#1 Guest_fundulus_*

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Posted 21 June 2011 - 08:24 PM

OK, I'm back for more fun with picture ID's. I took my Ichthyology class out this afternoon on a field trip to the Flint River east of Huntsville, AL, at the Winchester Road crossing where we've been working on several projects. We netted two species there today that I've never seen in the Flint before. One of them I knew, Bigeye Chub, and it's not so surprising that it would be in the Flint. But we netted four individuals that totally stumped me at first. Three of them, freshly euthanized, are in the two photographs below. I think that they're Silver Shiners, Notropis photogenis, a species that I've never seen but know to be fairly common just to the north in Tennessee. If they are Silver Shiners they're the first record ever in the Flint, and maybe the first times in years that the species has been collected in Alabama. The pictures aren't great, unfortunately, but I hope anyone familiar with the species can confirm, or not, my ID. These fish do have a pair of dark crescents between the nostrils, as well as a predorsal line. I left the pictures pretty large. Thanks, as always.

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#2 Guest_jblaylock_*

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Posted 21 June 2011 - 09:05 PM

Are there Emerald Shiners in the Flint?

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#3 Guest_fundulus_*

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Posted 21 June 2011 - 09:23 PM

That is a very similar species found in Tennessee tribs, and of course Emeralds have a huge range from Canada to the Gulf of Mexico. The fish in question seem to have a more pointed snout, but that's a very relative measure. They were collected on the edge of a large shallow riffle area, which seems more Silver than Emerald for habitat. The safe bet may well be Emeralds.

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#4 Guest_jblaylock_*

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Posted 21 June 2011 - 09:31 PM

You're right, the snout is more pointed. Peterson says 8 Pelvic rays for the Emerald and 9 for the Silver. That and the 2 dark crescents seem to be the way to tell them apart. The Emerald lacks the crescents...hmmm, maybe it is a Silver. I'm so bad at Notropis.

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#5 Guest_fundulus_*

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Posted 21 June 2011 - 10:26 PM

Notropis can confuse just about everyone, that's the challenge. It'd be better to bring the fish somewhere for people to see them in the flesh.

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#6 Guest_daveneely_*

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Posted 22 June 2011 - 06:11 AM

I've gotten silvers in both the the Elk and the lower Sequatchie more recently (within the past 2yrs), but the Flint is a good record. Your fish sure look like silvers, but I'm happy to verify IDs from the specimens if you need. Just drop them in the mail or swing by if you're passing through town.

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#7 Guest_daveneely_*

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Posted 22 June 2011 - 06:13 AM

Oh, and that's a good thing to include in the state report for Proc SFC this year, hint hint...

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#8 Guest_ashtonmj_*

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Posted 23 June 2011 - 08:20 PM

I'll agree with Dave on the silver shiner call. I've also collected them from the lower Sequatchie and lower Paint Rock.

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#9 Guest_Irate Mormon_*

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Posted 08 July 2011 - 11:24 PM

Got tooth counts?

BTW, that "Fine Science Tool" looks like a cheap plastic ruler. Bet it cost a pretty penny!

Edited by Irate Mormon, 08 July 2011 - 11:26 PM.

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#10 Guest_fundulus_*

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Posted 09 July 2011 - 10:47 AM

No tooth counts yet, just Dave's second opinion from looking at preserved fish. The Fisher rulers have usually been 10 for $10, and they work great in freshman biology labs!

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#11 Guest_daveneely_*

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Posted 09 July 2011 - 11:43 AM

No tooth counts yet, just Dave's second opinion from looking at preserved fish. The Fisher rulers have usually been 10 for $10, and they work great in freshman biology labs!

Tooth counts and anal fin ray counts are a little odd: 2,4-4,1 and 1,4- ; one specimen has 9 anal rays and the other has 10. They both have 9 pelvic rays and well-defined nasal crescents, and everything else screams N. photogenis. I'm pretty convinced they're silvers.

Bruce, have you thought of dragging a bag seine or trawl around down there? Might get all sorts of fun stuff...

cheers,
Dave

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#12 Guest_fundulus_*

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Posted 09 July 2011 - 04:45 PM

I'm going back to the site Tuesday afternoon with the Ichthyology class, taking my 20-foot seine with somewhat coarser mesh. The exact spot we netted the five silvers was a side channel of the river rejoining the river in a fairly steep gradient into the riffle system, in about a foot of water. There's a flowing pool with somewhat deeper water below the riffle system that we're going to focus on. Besides the two fish you have, I have another fixed in 10% phosphate buffered formaldehyde, and 2 in 95% EtOH. This area is also loaded with blotched chub, Erimystax insignis, both adults and a surprising number of YOY.

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#13 Guest_fundulus_*

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Posted 12 July 2011 - 05:11 PM

We went out to the Flint River this afternoon, and found the motherlode of silver shiners where I thought they'd be. The sweet spot is immediately below the riffles we usually sample in about knee-deep flowing water right on the edge of quiet side eddies over sand and exposed sandstone bedrock. Our third seine had a dozen silver shiners in it, on top of a few in the first two nettings. Interestingly we also caught a 6-inch smallmouth bass with the first silver shiners. I kept 9 silvers today, plus a possible juvenile, with 3 placed in ethanol and the other 6 in 10% buffered formaldehyde. I'm convinced that there's a significant population in this stretch of the river, one of two now known in Alabama; based on Matt's observations there is probably also a population in the Paint Rock River, the next large river east of the Flint. That has to be checked out, hopefully in the near future.

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#14 Guest_Uland_*

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Posted 15 August 2011 - 06:25 PM

Instead of starting a new topic on the same fish....I thought I'd piggyback on your topic Bruce. Please split this if this post is inappropriate.

Found in the Blue River Indiana.

Posted Image

All fish have the nostril crescents but they are different enough to question the ID.

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The largest fish is 4.75"

What do you think Dave? That bottom fish looks so terribly emerald to me ...but it has the crescents!
Any online tutorial demonstrating a good way of getting tooth counts on such a critter?

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#15 Guest_daveneely_*

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Posted 15 August 2011 - 08:05 PM

Hmmm. They do look suspiciously "photogenis-ish." What are pelvic fin ray counts? Pharyngeal teeth aren't different between emeralds and silvers - they're both 2,4-4,2. Particularly on EtOH-preserved fish, the teeth are very brittle and easy to break off while trying to extract the arch... I'll see what I can do for photos.

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#16 Guest_Uland_*

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Posted 15 August 2011 - 09:49 PM

Gosh Dave, that clue is right in the book for goodness sake. But with this, I'll remember and thanks for the help. All fish have 9 pelvic rays but two have 10 on one side with 9 on the opposite.
Speaking of brittle fish, they are not unmanageable but I do need to be careful when handling. Are there any tricks when doing delicate work on preserved fish?

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#17 Guest_daveneely_*

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Posted 16 August 2011 - 06:17 AM

Guess that cinches it (the 10s aren't that surprising, there is a bit of variation in that and occasional specimens do have 8 rays). Cool! Other than these, do you happen to know the last confirmed capture for the state?

Are there any tricks when doing delicate work on preserved fish?

Practice on less-important specimens first... fin rays are a bit problematic on EtOH-preserved stuff just because the membranes between the rays shrink and stiffen, and it's really easy to split or break them.

Edited by daveneely, 16 August 2011 - 06:18 AM.

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#18 Guest_Uland_*

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Posted 16 August 2011 - 07:26 AM

Guess that cinches it (the 10s aren't that surprising, there is a bit of variation in that and occasional specimens do have 8 rays). Cool! Other than these, do you happen to know the last confirmed capture for the state?

Practice on less-important specimens first... fin rays are a bit problematic on EtOH-preserved stuff just because the membranes between the rays shrink and stiffen, and it's really easy to split or break them.

I'm honestly not sure how often N. photogenis are caught in Indiana but I can say they were not difficult to obtain this section of the Blue River. I will check with Tom Simon when I gather the photos and report back to the forum. It does seem the area we sampled appears to be the western- most distribution in that part of the state.
I really do need to start working on internal anatomy and recently bought a decent dissection microscope to help. My eyes are really going quick.

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#19 Guest_fundulus_*

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Posted 28 August 2011 - 07:56 PM

As a follow-up on this thread, I went back to the Flint today with a large number of students to work on various field projects. One of them was collecting silver shiners. We found that we'd net 7 or 8 at a time, or none; they run in tight schools along the shore. I think we netted several juveniles too, although that remains to be determined. We're also going to visit some other sites along the Flint to see how widespread they are.