It's natural instinct will be to hunt. Don't keep it with anything the same size or smaller. With nothing else to eat and worms available in the dark, when it's hungry it will supplement a lack of live fish with live worms in my opinion.
Hey man, 3 years later, any update?I just checked my parameters again. Ammonia is at 0 PPM. Everything else is low enough to not be a concern. PH is at 8.0, we have well water. I have 6 large aerators running. I would like to thank everyone that chipped in for their help. I'll keep updating you guys as time goes on. I've also been trying something. I put a thawed minnow where he usually frequents, then I turn the lights off and wait 30 minutes. After turning the lights back on, I come back and usually the minnow is gone. It may be the sturgeon, but the sturgeon have really small mouthes and I don't think they could eat such a large minnow. Usually they can't even eat half a minnow. At about 8 PM yesterday I put a small piece of worm in to feed my brook trout. If you guys ever can keep a brook trout, they are amazing fish. After I dropped it in, the catfish swooped in and ate it. It made me super excited! So now I can tell you guys that he is eating, just not as much as he would in warm water.
Like I said, I will keep posting updates as time goes on. So you guys will know if anything happens.