Bucktooth tetra with red eared slider?

[brown_snake]

I also suggest livebearers. You could set up an area where the turtle doesn't get them easily. Bigger fish are easier to catch and turtles are equipped to kill most any bigger species. Fake plants, driftwood, rocks and anything else you can come up with to break line of sight. The parent will also consume the fry, so you want places even where they have trouble getting all the fry. Once the numbers are up they should reproduce fast enough where they can never eat all the fry.

Oh, okay. Someone actually told me that oscars and other large cichlids are aggressive and imposing enough to intimidate most turtles into submission. But based on what you've said, I suppose a sufficiently ravenous turtle might decide to go after an oscar anyway.

What about ghost shrimp? Do they breed quickly as well? Apart from the live-bearers, I'm also hoping to introduce a self-sustaining colony of crustaceans that the turtle can snack on from time to time. Thanks so much.

 

[Woefulrelic]

The thing with fish tanks is that eventually fish run out of other things to do. A turtle will eventually decide at some point its going to try. It usually will just be a swipe or a bite, but they will start with fins and eventually chunks of a tail. Your fish will end up unable to run eventually, so anything valuable shouldn't be considered long term.

Ghost shrimp can probably work as well as cloning crayfish. Turtle should have no issue chomping them down, you could also try some cheaper cichlids like convicts originally. Hopefully the turtle can learn to not target them until a while later. Convicts also breed quickly, but I have no idea how they work with turtles because I know little about turtles. The only thing I know is that turtles are equipped to easily kill fish, and eventually they will.