All the things that make red shiner an invasive species speak to its potential as a forage species within its native range. Where the red shiner is not native, it is typical that other closely related native species can play a similar role as forage. Examples are species like blacktail shiner, spotfins, and satinfins.
It is great to learn that vendors of aquarium specimens are being careful to restrict sales to regions where they are native. I would just add this. It's each pond owner's personal responsibility to ensure his fish and forage are suitable for his regions native fauna. Our water flows downstream and our fish swim both directions in high water. What we do in our ponds impacts our neighbors and local biodiversity.
