what do you have in there? from the looks of it the flowerhorn looks reasonably large. and from my experiences with flowerhorns, there isn't much out there that can take down a larger male like this one. the beatings almost look like they were drawn out.
i would immediately remove the busted up fish, and try a treatment in a "hospital" tank. i would also try to find out what inflicted this damage, and maybe put that fish in a solo tank.
i would immediately remove the busted up fish, and try a treatment in a "hospital" tank. i would also try to find out what inflicted this damage, and maybe put that fish in a solo tank.

