My 65g is undergoing some stocking changes due to some aggression issues. At the end of the changes, I'll have either one male longear sunny or a M/F pair, and a warmouth. I'd like to have a bit more variation, so I'm looking for suitable tankmates. Thing is, warmouths have earned their name. Mine is about 4" at the moment, and he was trying to eat some >3" shiners- hence why I moved said shiners. I'm pretty sure he could have eaten them if he wanted to.
I'm reasonably certain my warmouth is a female- there's no orange on its anal fin. I could be wrong, though, since it's young. I'm assuming it's going to reach something like 7" long, maybe a bit larger, and I'm somewhat concerned about how big that mouth is going to get.
These are some fish that I'm considering, and I'll likely only pick one species:
Mexican tetras (4" long, but tall-bodied)
Creek chub (possibly- what size do they typically reach in captivity?)
Madtom (not tadpole, too small, but maybe freckled or stonecat if I can find one)
Logperch (maybe- tank is low-flow, but I've found logperch while diving in 7' of water in Lake Travis- no flow there)
The madtoms are looking like my best option. Mexican tetras are possibly too small, creek chubs are possibly too large, and logperch are skinny, small-ish, and possibly high-flow fish. A tadpole madtom would probably get caught in the warmouth's throat, and freckled madtoms are also on the smallish size. Stonecats evidently reach about 8" in aquariums, sometimes larger, so they'd be far too big for a warmouth to swallow.
If the stonecat is my best option, what's the best way to ID them? We have various types of bullheads, and I don't want a bullhead in my tank. Waaay too big.