I used to have a tiny one that looks like the one pictured but it died.
I also have done some googling and neither Zungaro Zungaro or Brachypatystoma flavicans Look like the picture.
Microglanis Iheringi (grows to 6") looks like the one pictured above
Pseudopimelodus bufonius also looks like it but looks like it looses it color when older?
I would say maybe check over on planetcatfish.
But anyways whatever it is it is beautiful!