Is this a common or something else?

[addictinganimal]

The LFS didn't know what it was and sold it to me for the same price as a common. I looked through the cat-elog and it looked like a few of them.

Common with mottled coloring.

Hypostomus sp. (L139)

A couple others on there looked like it too. I have a 125g lined up for him, so it's fine if he's a biggie.

[sidguppy]

it looks like a Hypostomus to me, but it's tricky without a dorsal fin ray count

check the number of rays in the dorsal. if it's 8 (or 9 including the spine), it's a Hypostomus

if you can count up to 11 or more, it's a Pterygoplichthys. but the 4 bands and the sturdy shape point at Hypostomus.

[addictinganimal]

Thanks for your quick answer! Here's another view of him:

[sidguppy]

you're the proud owner of a Hypostomus!

the good news:
Hypostomus are much rarer these days than Pterygoplichthys, and most species of Hypostomus reach an average length of, say, 10" or so.
some stay at 8", others can reach 12", but in all, it's not going to be a tankbuster like the common plec.

the bad news -small though- is that these guys are next to impossible to identify properly without knowing the exact spot where it was caught
but that's not a real issue when it comes to housing and keeping it, isn't it?

[addictinganimal]

WHOOHOO! Very, very cool. More room for other fishies then. (This is going to be the first member of the 125g Club once I get it set up.) Nah, the exact species isn't important, but at least I know what he is in general.

Man, I love plecs.

Thanks!