maybe the one female is jealous of the way the other is lookin' at her man!
all joking aside, fighting in my tanks with plecos typically happens with males only, I have yet to see females fight. Do you have pictures of each individual fish? It seems like you have plenty of caves if there are only 3 plecos and 12 caves.
I've seen fighting amongst females of several different species, and genera, and this really doesn't sound that uncommon. They're simply trying to establish who is the dominant fish in a new territory. Yes, even females have a hierarchy and the change in surroundings means they have to reestablish that.
Impossible only means that somebody hasn't done it correctly yet.
I guessed as much from the location and the price. I am interested in the statement they had been in the shop for 2 years as although they had some the weekend just gone there have certainly been periods within the last 2 years where they have had none (unless they were tucked away in a display tank??)
Mr. Rate: That's how a conspiracy works. Them boys on the Grassy Knoll they were dead within three hours, buried in the damned desert, unmarked graves out past Terlingua.
I have raised over 1000 Peckoltia compta from many different breeding specimens but I have never seen any of my females fight. I have seen a couple males get into a fur ball though. Of course just because I have never seen the females fight doesn't mean that they may. Most commonly I have seen females with scrapes on their bodies as the breeders sometimes get rough with each other