Maybe we're just talking about two different things :lol:
I mean common as in:
http://www.thetropicaltank.co.uk/Fishindx/compleco.htm
These ones usually don't have much brown or red in their colouring.
Maybe you mean 'common' as in not rare? Redspot & Goldspot are not rare... dunno, I might be completely wrong though. As I said not an expert on catfish
Yours, Hummingbird, looks like a Redspot to me?!?