It was in a group of six adult zebras, and it looks like there is mainly males, possibly only one female among the six.
There has been evidence of aggression in the tank on and off over time, five have been grown on from fry in the tank, the other was a mature male i bought, and the fish are now four or five years old.
Any ideas on how best to treat the fish?
It is now in another tank with some rummy nose tetras.