Thanks for taking the time to look at and make detailed comments on this
mystery fish. I apologize for not getting back with you sooner. I have
been doing a bit of research on characteristics of the bigmouth shiner
(Notropis dorsalis) and its look alikes, sand and mimic shiners (N.
ludibundus and N. volucellus). One of the best sites that I have seen to
describe the differences of the fishes in question is the Fish
http://220.127.116.11/fish/final_fish/finalfish.asp?85. Fully understanding
that I am an amateur at this, I have been using the database, Fishes of Ohio
(Trautman), Peterson's Freshwater Fishes, and some other references and I
think that I can present a relatively sound argument that this fish is N.
dorsalis. Here are some of the characteristics:
The "mouse tracks" or as other books call it "punctated lateral line" is a
big consideration as to the proper ID of this fish. Looking at the pictures
of the mystery minnow, there does seem to be pigmentation along the lateral
line, but it seems to correspond to pigmentation with the scale edge. None
the less, there is pigmentation along the lateral line scales. The
preserved specimen in the FIDatabase seems to have distinct punctated spots
along the lateral line but I don't know if this is a result of preservation
Another difinitive characteristic is the shape of the lateral line scales.
In N. volucellus the scales are "much taller than wide" as described by
Peterson. The FIDatabase also indicates that N. dorsalis "has moustracks
but does not have elongated scales". This fish does not seem to have that
characteristic and in my opinion would therefore rule out N. volucellus.
All three fish in question have between 32 and 38 lateral line scales so I
do not think that this can be used as a determining characteristic. Rob,
you mention elevated anterior lateral line scales. I am not sure what this
is and their doesn't seem to be anything in the pictures to describe it.
However, Trautman does mention for N. dorsalis, "Other species of shiners
with 8 anal rays have either a distinct lateral band; or greatly elevated
lateral line scales; or spot at the caudal base; or spot on the dorsal fin."
Trautman's description of N. volucellus is, "The complete lateral line
contains 33-38 scales; those in the anterior half of the line greatly
elevated....". If you are correct in the elevated lateral line scales, then
you may have a point here.
The mouth is very difficult for me to compare to the eye diameter. Most of
the references indicate that the mouth of N. dorsalis is larger than the eye
diameter; the other two species smaller than the eye diameter. Without the
specimen in hand, I couldn't measure. In looking at the head comparisons of
the preserved specimens in the FIDatabase, the shape of the nose and mouth
looks very similiar to the mystery fish. Peterson describes N. dorsalis as
having a "long snout; large sub terminal mouth" and the other two species a
"rounded (N. ludibundus) or broad rounded (N. volucellus) snout; small,
slightly subterminal mouth".
Probably the best advantage that I have of course was to look at the live
specimen. When observing it, it is pretty clear that the eyes do face
dorsally, something that is not very evident on the pictures. Looking at
the fish head on, it does seem to have a triangular shape, whereby being
flattened on the bottom, characteristics of N. dorsalis described by
N. dorsalis is considered threatened in Ohio and it would be somewhat
unlikely to catch it in a large, heavily urbanized tributary of the Cuyahoga
River. It is currently only known from the two Lake Erie river systems just
west of us here at the zoo. It would definitely be more common to find
either of the two other species, however the fish still seems different to
me. I just sent the fish down to Dr. Cavender, curator and professor at
Ohio State University who is very familiar with Ohio fishes. I gave him
permission to use the specimen in the best interest of science. I hope to
hear back from him soon.
Thanks again for all your interest and help. I still am open to any
comments, suggestions, or corrections. I am not an expert by any means-I am
just having fun pulling my hair out!
Here is the website to view the pictures again.
Cleveland Metroparks Zoo
216.661.6500 ext 4485
H. dorsalis also has melanophores along both sides of the lateral line
(like N. ludibundus), at least out here. The photo seems to show a general
"duskiness" along the lateral line, but not what I would describe as a row
of "=" signs encompassing the line. Maybe these are the "mouse tracks"
described on the webapge you referenced.
Mostly, though, its the mouth. It appears distinctly subterminal in the
photos and it is very nearly terminal in H. dorsalis that I have collected.
I don't have the actual specimen, however, and will defer judgement to
anyone who has actually examined same.
Good luck and best wishes.
Is there some reason you're discounting the mimic shiner (N. volucellus)?
Although I don't know where this fish came from it appears to have 34
lateral line scales, elevated anterior lateral line scales, the correct fin
placement, no darkened mid-dorsal stripe (that would be present in dorsalis
and ludibundis), and mouth placement (although the snout does not appear to
be perfectly typical)consistent with volucellus. Although I hesitate to
attempt to ID confusing shiners from photos, I'm certain its not dorsalis.
sorry I haven't had a chance to reply to you fish question, I was out of
town for a few days. I was wondering in you had any internal photos? In
particular the lining of the body cavity(black, speckled or silver) and the
shape/length of the fish's intestine (long with lots of loops, medium amount
of loops, or s-curved). This would be a big help.
American national fish and wildlife museum
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