10 replies to this topic

[juhason]

What are the key differences between these two? I found a great spot in the Des Plaines River that has lots of shiner activity. I know both are within my range. I caught (and released) a couple and for the most part they looked like Spotfins to me but some of them were a bit more "metallic" looking and had yellow/orange fins on the bottom, and I'm thinking that might be steelcolor? I'm not too sure I know these fish are very similar. 

 

I will get a picture either tomorrow or thursday when I go back there! But any advice will be appreciated.

Edited by juhason, 03 October 2017 - 09:42 PM.

[Casper]

I have them in my backyard, both swimming side by side.

The only way i have learned is by breeding males.

The Steels have red noses.

I would like to know as well to discern young males and females while snorkeling or in hand.

There must be something else to key to.

[juhason]

I have them in my backyard, both swimming side by side.
The only way i have learned is by breeding males.
The Steels have red noses.
I would like to know as well to discern young males and females while snorkeling or in hand.
There must be something else to key to.

I suppose I might have to wait until spring to know exactly what i'm getting, I think I might prefer the steel color. But yes if there's anything else I'd like to know!

[Matt DeLaVega]

Midway between the lateral line and the dorsal is a slight iridescent line that runs from head to tail in spotfins. Steelcolor's lack this. It helps to have the fish in hand so you can change angles by rolling it back and forth in the sunlight. Once you notice it, it becomes easier to pick up on. Difficult to see this in photos. It works though. One of the many things I have picked up on from hanging out with Brian Zimmerman. Probably works well snorkeling as you get to see changing angles in the light.

[juhason]

Midway between the lateral line and the dorsal is a slight iridescent line that runs from head to tail in spotfins. Steelcolor's lack this. It helps to have the fish in hand so you can change angles by rolling it back and forth in the sunlight. Once you notice it, it becomes easier to pick up on. Difficult to see this in photos. It works though. One of the many things I have picked up on from hanging out with Brian Zimmerman. Probably works well snorkeling as you get to see changing angles in the light.

Awesome tip thanks so much! i'll try this out. now i'm not the most familiar with fish anatomy. In this picture it's not that darkish like through the center right? It would be between that and the top fin?
https://www.google.c...tqomO9cFl1_RyM:

[Matt DeLaVega]

Look at the lateral line. Then between it and the top of the fish you can see a distinct color change in between. That is what you are looking for. In a fish in hand the division of colors has an iridescent line separating them. Easier to learn from one in hand. You are on the right track.

[juhason]

Look at the lateral line. Then between it and the top of the fish you can see a distinct color change in between. That is what you are looking for. In a fish in hand the division of colors has an iridescent line separating them. Easier to learn from one in hand. You are on the right track.

Ok I'm heading out there tomorrow! Thanks for the help

[ChrosomusEnthusiast]

@=

 

Look at the lateral line. Then between it and the top of the fish you can see a distinct color change in between. That is what you are looking for. In a fish in hand the division of colors has an iridescent line separating them. Easier to learn from one in hand. You are on the right track.

I learned the same trick from Brian this past summer. Anal ray counts are also helpful, spotfins usually at most 8, while steelcolors usually have 9 (If you have a big enough individual to actually see them). 

[smbass]

First off Zach good to see you on here! Now that it is winter and I have a little more free time I hope to frequent the forum some again. You guys did a good job describing the differences between these two but I figured I would add a little and some photos since these are some of my favorite natives to keep in aquariums...

 

Steelcolor... Breeding males have the pink/red nose, very enlarged rounded rear edge to dorsal fin, yellow lower fins, scales have dark edges giving body a cross hatching appearance, and nice steel blue sides with white tips to the tail. Females and non-breeding males I look for the absence of a well defined gold line down the side that is best seen looking at the fish at a somewhat downward angle or just in the water it is more obvious. Also you can use the 9-10 anal ray count but I have seen quite a few Spotfins with 9 anal rays so certainly use these in combination. Also rear edge of dorsal should be somewhat rounded and over all body should look stockier/taller with a taller caudal peduncle than that of a Spotfin.

 

Spotfin... Breeding males lack the pink nose, have a very straight rear edge to the dorsal fin, bright white lower fins in most populations (upper Mississippi Basin display yellow like Steelcolors most places including the area being discussed), scales have dark edges giving body a cross hatching appearance, and have steel blue sides with white tips to all fins. Females and non-breeding males have a well defined gold stripe down the side that is best seen looking at the fish at a somewhat downward angle or just in the water it is more obvious. Also most Spotfins have only 8 anal rays but this is not consistent and has caused a lot of issues with the supposed distribution of Steelcolor. Spotfins have a more elongate body over all and a narrower caudal peduncle. Even I don't get all of these right, I make sure I find an obvious male Steelcolor before I declare them definitively occurring at a site. 

 

As an example in 2016 I found what I thought were young Steelcolor Shiners in the Little Muskingum River which there were no records of in this system other than a single specimen from Milton Trautman in 1929. This year I was back in this system with three helpers(thanks Andy, Ben, and Zach!) and we worked the area over hard until we got the definitive answer of a very nice breeding male that I will post the photo of below. We also caught about 8 other females or non-breeding males this year. This population represents the most upstream definite population (confirmed by vouchers... Trautman's 1929 fish OSUM 10870 and our 2017 fish OSUM 118147) in the Ohio River basin. There are reports and even preserved specimens from further up the main-stem Ohio but these all turned out to be miss-identified Spotfin Shiners when I investigated all available material a couple winters ago.

 

Breeding male Steelcolor Shiner from the Little Muskingum River August of 2017

 

Female Steelcolor Shiner from the Scioto River Ohio

 

Non-breeding male Steelcolor Shiner Scioto River Ohio

 

Comparison shot of two small fish Steelcolor top and Spotfin bottom showing absence/presence of the gold stripe Elk River WV fall 2017

 

Breeding male Spotfin Shiner from the Kokosing River Ohio

 

Female Spotfin Shiner from the Kokosing River Ohio

[smbass]

And here is a Spotfin Shiner from the Kankakee River (upper Mississippi River basin) older photo so not as good...

[Matt DeLaVega]

Nice. Thanks Brian.