6 replies to this topic

[sideburns24]

Just wondering if someone could help me understand the difference between Eastern and Western Blacknose Dace. I know taxonomy is a subject that is seldom universally agreed upon but wanted to know what some of the more learned members had to say. 

 

Peterson (2nd edition, 2011) has them listed as subspecies; Eastern as R. atratulus atratulus, and Western as R. a. obtusus, with coloration being the main determining factor. I am finding many other sources that are listing them as separate species, but the illustrations or pictures accompanying make it more confusing with Westerns being shown as what would pass for an Eastern according to Peterson. 

 

I am mainly interested because Blacknose Dace are one of the more common species I encounter in my local waters and are certainly not shy when I am snorkeling, so I see them a lot!

 

I would also love if anyone could point me to any articles they know of about this topic!

[JasonL]

We have the western variety here in KY.  I don’t think there is any reliable way to tell them apart other than genetic studies and location.  

[Matt DeLaVega]

Yours are western in Ohio.

[sideburns24]

So the deciding factor at this point is geography?

[Matt DeLaVega]

Not only geography. There are differences between western and eastern. For practical purposes though, geography is often the most important factor for field collections. Michael Wolfe always says "Know where your feet are".

[JasonL]

Yeah pretty much.  

[dac343]

In case anybody was interested in the Molecular Phylogenetics

Attached Files

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