I've only done limited research of spotted bass with smallmouth and found the spotteds would tend to outcompete the smallies, overpopulate and stunt. Undesireable, obviously. Would imagine this could take place if on their own as well, but a smaller pond and aggressive management could certainly curtail this. Very interested in what experts would consider viable forage options for this scenario. Travis likes a sunfish abbreviated RBS (redbreasted sunfish?) in some instances with smallmouth. Maybe that's a start. Or maybe even just bluegill if you can manage them along with adult spotted bass.
