what you have is a pseudopimelodid species aka S/A 'Bee cat'. It's a batrochoglanis raninus, rare in the hobby and can be expensive from some sources. Nice find, they don't get too big, maybe to 9" or so. They're little predators though so don't keep it with things small enough to eat unless they're intended to be feeders. I had one for many years, really cool looking fish...
Unfortunately they are very slow growing fish, I got mine at 1-1/2" and it took years to reach 4" perhaps why a larger specimen can be expensive? In any case a good deal and nice find...
One of my all time favorite catfishes, good price for it as well.
I had one many years ago and sold it - wish I kept it.
I have not seen any for sale since that time.
Yours looks great and best of luck with the little beast.