Got 4 koi's, they sometimes swim "against"(touching) the armatus and mirror the movements. It's weird like mating ritual.
Never took out tarpon, just treated entire tank. No more aggression, guess he realizes it was a waste of time or the fact that I'm feeding him larger fish. i.e. sardine,yellow croaker,gourami instead of the smaller smelt which is no longer eaten. What I need is a mfg to make large horse size food sticks to stuff into fish instead of tediously stuffing current size sticks into the larger fish.