Spotfin or Steelcolor

To everyone,

Below is a couple of pictures of a fish at the Children's Museum in Indianapolis. When they were first put into the pond they were young and looked like Spotfins. Now I am not sure. I just need confirmation one way or the other. They are going to make signs with the names and these pictures so the kids can ID the fish.

Bill F.


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I would have to say those are steelcolors.

I would disagree, I would say this fish is a spotfin shiner, a clear shot of the anal fin or just a ray count would be more definite. Spotfins have 8 and steelcolors 9. I think I am getting 8 from the pictures but the fin is not fully extended so I am not entirely sure if that is accurate. Also the coloration and body shape also say spotfin. Your fish is obviously a breeding male and breeding male steelcolor shiners have a pinkish red spot on the very end of the snout. It almost looks like they have been rubbing their nose on the side of the tank to much but it is actually coloration. If you have the petersons field guide take a look at plate 18. this only works on fish in full breeding color (which this fish does appear to be), and only on males. Nate Tessler had a nice steelcolor male in coloration like this for a while. Nate if you read this and have a picture of that fish could you post it? I wish I had taken the time to picture tht guy while you had him. Also steelcolors are more robust than spotfins especially large males and this fish to me looks like a very nice healthy male spotfin shiner. I should also mention that the anal fin ray count is not always a 100% accurate with these two species, you do ocasionally (probably less than 2%) see spotfins with 9 or steelcolors with only 8.

hi bill...
Thats a very good reply from brian z. they are a tough fish to field id for me unless.... and we have both in my backyard... south chick creek. the only way i surely can id the steelcolors is by the bright red rudolph noses on the breeding males. they get much more spectacular than this picture i can tell you. wow. last year i laid in the creek and watched several males constantly displaying just inches from my mask. a beautiful fish. in the right conditions i would suspect your individuals will intensify as the season progresses.

casper

I'll take your word for it Brian, I'm bad at cyprinid ID and never seen a steelcolor in person. I have seen lots of spotfins and have a few in breeding coloration. According to the Peterson guide the steelcolor males have enlarged dorsal fins and it looks like that specimen does as well. Much larger then any spotfin I have seen. Also the fish in the picture does appear to have a bit of red on the nose but perhaps I'm just looking to hard.

I think your looking too hard for the red, but I do think you have a point with the dorsal. I noticed that too and it made me hesitate because it is more of a steelcolor dorsal but everything else about the fish (unless I screwed up the anal fin ray count) points toward spotfin.

I think your looking too hard for the red, but I do think you have a point with the dorsal. I noticed that too and it made me hesitate because it is more of a steelcolor dorsal but everything else about the fish (unless I screwed up the anal fin ray count) points toward spotfin.

Thanks for all the replies. I have much larger picture than I posted(dial-up). Below is a blown up of the anal fin.

Bill

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Just for fun, I'll offer a contrarian view and suggest that it is a steelcolor based on the convex posterior margin of the dorsal fin. I think spotfins have a straight margin. Can't wait to hear the results of the ray count!

I hope you don't mind my slight edditing of your photo. I get 8 anal fin rays, you have to count them from the base where they start not out on the fin because they branch out. The dorsal fin does bother me a bit because it is awful large which is tipically a steelcolor character but I have seen large male spotfins with a large dorsal as well. If you keyed this fish out it would come out as a spotfin shiner unless there is a ray hiding behind the body on the back edge of that fin. I also still think this fish has enough of the breeding drab that you would see the red snout if it were a steelcolor as well.

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I declare it a hybrid!!

I declare it a hybrid!!

Hybrid! Hybrid! Hybrid! Hybrid! ...

I hope you don't mind my slight edditing of your photo. I get 8 anal fin rays, you have to count them from the base where they start not out on the fin because they branch out. The dorsal fin does bother me a bit because it is awful large which is tipically a steelcolor character but I have seen large male spotfins with a large dorsal as well. If you keyed this fish out it would come out as a spotfin shiner unless there is a ray hiding behind the body on the back edge of that fin. I also still think this fish has enough of the breeding drab that you would see the red snout if it were a steelcolor as well.

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No problem with editing the photo. It helps some of us on how to ID fish. I do have a question pertaining to the dorsal fin.
These fish are beening kept in a pond setting with a waterfall for the only moving water. Is it possible that the dorsal could grow larger because of the lack of water flow? I would think in fast moving streams a larger dorsal would be detrimental to fast swimming. Just thinking.
By the way I guess it could be a hybrid. Maybe a cross between a Hi-fin Platy and a Spotfin?


Bill

No problem with editing the photo. It helps some of us on how to ID fish. I do have a question pertaining to the dorsal fin.
These fish are beening kept in a pond setting with a waterfall for the only moving water. Is it possible that the dorsal could grow larger because of the lack of water flow? I would think in fast moving streams a larger dorsal would be detrimental to fast swimming. Just thinking.
By the way I guess it could be a hybrid. Maybe a cross between a Hi-fin Platy and a Spotfin?
Bill

Well, that's interesting. If the fish had the genetic potential to grow a larger fin under varying environmental conditions, then yes, that might explain it. But I'm not aware that spotfins have this ability. If you're talking about adapting by genetic change, that could take many generations. I do have a comment about the fact that the fish was apparently reared in an artificial pond from a young age: A change in nutrition and environmental conditions could easily effect transient characteristics like breeding color and body condition. Also the fact that February in Indiana is not prime breeding season for steelcolors. So the absence of the red nose and other characteristics typical of breeding steelcolors may be explained by the season and where the fish was raised, outside of its natural, presumably optimal, environment. I say all this just for the sake of argument. Can't resist a good argument

Mark

Um, this might be all the cold medicine I'm on.... But Brian, I think you counted the membranes, not the rays? I see 9 rays.

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Todd I don't think it's the nyquil. I thought at first maybe the lines were drawn after the rays but there would still be a 9th line. I tend to agree that the lines Brian illustrated are on the membranes and not the rays.

Honestly I'm a bit torn on what it is...if it is a nuptial male the dorsal fin and what I am seeing are differences in size between tubercles suggest steelcolor, but the overall body shape and fin pigmentation is saying spotfin.

I absolutely hate distinguishing these two species, esp in the field. But will say I have NEVER seen a spotfin in spotfin-only territory that had a dorsal fin that even looked remotely like that. Looks like that thing got cross bred with an ashy darter!

Bill, did they come home from that last Tippecanoe trip? What we collected at Paulaski and down near Delhi all ended up being steelcolor. (what was even cooler was the fish we caught in that little trib were silvery minners

This fact might tell more than getting tricked with artifacts of the flash. Which, btw, the photography here is STUNNING. That top pictures is just sexy!

Todd

Well! Now I have to disagree with the people who are agreeing with me! I think Brian did count the rays. Like he said, he counted them at the base of the fin before they fan out toward the margin. Look at the photo with no red lines on it. The membranes are the lighter zones, and rays, fanning out, are the darker zones. No?

I'd like to hear more about the purported occurence of enlarged dorsal fins in spotfins. In Petersen's, they claim this does not occur.

Mark

I'm pretty sure the first ray is folded up on the second and the 9th ray is up against the body.

I'm not going to argue it to the ground though. Doing minnow ID's online from pictures will do nothing but get you into trouble every time <wink><wink><nudge><nudge>

Todd

I hope you don't mind my slight edditing of your photo. I get 8 anal fin rays, you have to count them from the base where they start not out on the fin because they branch out. The dorsal fin does bother me a bit because it is awful large which is tipically a steelcolor character but I have seen large male spotfins with a large dorsal as well. If you keyed this fish out it would come out as a spotfin shiner unless there is a ray hiding behind the body on the back edge of that fin. I also still think this fish has enough of the breeding drab that you would see the red snout if it were a steelcolor as well.

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I'd have to agree with Brian Zimmerman's count of the fin rays. I used-to count fin rays for a living and it looks to me like he's done it right. As far as the species Id, ???? It doesn't look like any Spotfin I've seen.

I'd have to agree with Brian Zimmerman's count of the fin rays. I used-to count fin rays for a living and it looks to me like he's done it right. As far as the species Id, ???? It doesn't look like any Spotfin I've seen.

I now see how much trouble it is to ID fish in the wild. This has become a challenge now!

I was looking through some of my books and came across some differences between the fish list on Page 156 of "Fishes of Tennessee". I am quoting this from the book itself. "In fresh specimens spiloptera has a faint wash of yellowish pigment in on the caudal fin; this fin is clear in whipplii. In spiloptera, the lateral stripe on the caudal peduncle extends little above the horizontal myoseptum, has a rather definite dorsal margin, and the oblique myosepta within the lateral stripe appear as narrow white lines; in whipplii, the lateral stripe on the peduncle extends well above the midline and fades more gradually dorsad, and pale myosepta are not visible within the stripe. In spiloptera(except nuptial males) the interradial membranes of the dorsal fin lack pigment except for the spot on the posterior membranes; in whipplii all dorsal fin interradial membranes are liberally sprinkled with melanophores in juveniles and adults." Not sure if this helps or not.

I also came across this website with more differences.

http://www.outdooral...shiner/spotfin/

Todd,

These were collected in Morgan County which is Southwest of Indianapolis. In fact I have 15 - 20 of them in my 125. hey haven't colored up as well as this one, yet. Some of the larger ones are getting some yellow on them. No matter what it is, they are nice ones in an aquarium.

Bill