It's a common issue when plecos start fighting. They heal quickly (a couple of days) as long as they are healthy and the water conditions are good.
But expect to see it more as many plecos get quite territorial as they get bigger, and who knows what they get up to at night when you aren't watching. Most of them have some sort of defensive (or offensive) spines on the sides of their heads and will bash each other when they fight.
Ian
But expect to see it more as many plecos get quite territorial as they get bigger, and who knows what they get up to at night when you aren't watching. Most of them have some sort of defensive (or offensive) spines on the sides of their heads and will bash each other when they fight.
Ian