For those of you who are interested, I emailed Kevin Meneau last night to ask him about both the mutated smallmouth and also the assertion that Gasconade fish seem to have characteristics exclusive of similar nearby watersheds such as the Meramec. This was his response:
I've seen this type of issue before, in several MO watersheds. However, the incidence is rather rare (much less than 1%). It is not clear if this is a result of genetic mutation or environmental condition (metals from mining). Given we see this issue from several watersheds, I would lean toward environmental condition, rather than something genetic.
I'm not aware of any evidence which establishes specific strains or appearances of smallmouth bass, by watershed. Given the relative geographic isolation of the Meramec from the Gasconade, it may be possible. But, I've not seen anything definitive.