Ancistrus sp X?

I have a group of these plecos in an invert tank of mine. They were labeled as Ancistrus dolichopterus at the distributor. And, supposedly from a reputable German source. However, I had my doubts of them being those. as they have grown out, I am pretty sure they are not A dolichopterus. I am also sure they are not common plecos. I have kept and bred those for some time.

These plecos are much smaller than the commons, the largest male is maybe 3" and the femal 2 to 2 1/2". Their color varies from dark grey to black. The spots are mostly white, and fade to greyish as the fish darken up. The females in particular look black with white spots. The tails look very like commons, with nice white tips.

Great pics mate.....
Ive seen a few of these before cant think what they were....
letme have a mooch about for you...

Sorry Zezmo, I can't tell you what it is , but I can tall you it's not L183 A.Dolichopterus.
J