Just got this little ? boy from my LFS from a man who used to breed Ancistrus and he's sure that's what I've got....but which? He's about 2" and has gone into my big tank with a Leopard Frog L134 and Golden Nugget L018
honestly it looks more like some type of peckoltia to me. dark spots on a light body rather than white or yellow spots of a dark base. i'm going to look around.
The nearest I can find on Planet Catfish is Hemiancistrusspilomma L036. Although it has similar markings and the yellow band at the end of the tail, the spots on the face look smaller.