Mmm, weird one. Doesn't look like a gibbicps to me because it doesn't have the rectangular dorsal fin, this one is triangular. Maybe it's a common, but I am not 100% sure what it is.
I believe it is a hypostomus sp. but a better shot of the dorsal would help. Commons(pterygoplichthys pardalis) will have 10 or more dorsal rays where the Hypostomus sp.(also often sold as commons) will have 8 or less.
since there are so many species of commons the possibility is there.. but does not look like a common to me... hope Davo the pleco expert gets a chance to see them .. he will know.Both very nice plecos