Thanks everybody for the replies...although not what I was hoping to hear.
To explain: Because I have a 15,000 gallon outdoor pond, an elderly gentleman insisted I have his 100 gallon tank with several fish that he could no longer keep up with (it was sold, set up and the fish recommended to him by a local mom & pop aquarium shop). One of these was “a catfish” that was obviously outgrowing the tank that he believed I could put in the outdoor pond.
We did put him in the pond last summer and back in the tank in the fall. Then by this spring he was much bigger, pulling at every hose, tearing up everything in the tank, even making squawking noises to get my attention. So again, we put him in the pond (and he was soooo happy to be there). Now it’s fall again, and there is absolutely no way he can fit back in that tank. We contacted the store that sold him to the elderly gentleman to see if they could re-home him and they insist he can adapt and will be fine in the outdoor pond since at its deepest it is 5 1/2 ft.
At some point along the way I did google search to eventually discover he is a Ripsaw catfish and indigenous to the Amazon. But I was assured he could adapt to the pond. I live in WV where winter temps probably average around 30-40 degrees in the winter but usually dip much colder a few times each winter. We have a heater to ensure the pond doesn’t freeze over solid, which is sufficient for the koi and goldfish that live in it.
But it sounds like there’s absolutely zero chance “Carl” (what we named Mr. Ripsaw Catfish) can survive anything remotely close to those temps. Now I have no idea what to do with the poor guy. And I’m sooo pissed that this aquarium shop sold him to someone along with a 100 gallon tank. ?