Trinidad was my first guess too. I'll have to count the rays on the dorsal when I get home. Thanks for the link.
I looked up the Hypostomus sp. and he looks like them too, possibly the L138, it's just so hard to tell.....alot of them all look alike.
I just wanted to know for sure as he is a bit aggressive. I will say he is an excellent tank cleaner.....other than the constant poo !