PLEASE HELP Problem Yellow Tang Vs Mertensi Butterflyfish

[dirk_brijs]

I introduced today a Mertensi Butterflyfish to my system.
DT is 170gallon.
All other fishes seem to be ignoring him but my Yellow Tang is showing some serious aggression to him.
Will the behavior last or will it stop after a while?
How long should I let this go its course before I pull the trigger and decide one of the 2 has to go?
Which most likely will be the yellow tang as he has shown aggression previous to other new additions in the tank.

 

[rosemoondust]

The problem with fish is that they are like a pack of dogs. The alpha fish will usually pick on any new comer fish until they learn their place. However, my foxface cannot be placed into a tank with another foxface or any other fish that even remotely resembles a foxface. She just seems to hate anything that looks like her, which has resulted in the death of some fishies. If the aggression does not stop after a day or two than you must return your new fish. If you see any extreme aggression like your yellow tang ramming into your butterflyfish or nipping at the fins than it is probably is best to return your new fishy.

 

[falconut]

I've seen this with Yellow Tang and Copperbands. There is apparently something about butterflies that some Yellow Tangs don't like. If it's real bad, I'd consider taking the Yellow Tang out immediately and move him to another tank. Then you could try again after the Butterfly settles in. Butterflies are pretty delicate, so it's not a good idea to have them stressed while trying to adapt.

 

[tcmfish]

This should have been expected, but hey we all learn If you can catch one then, yes I would. You could put it in the sump for a while. If you catch the butterfly... let it recoup in the sump and then when you re-introduce it use some sort of acclimation container where the tang can see the butterfly but not touch it. This goes for any new additions similar to an existing fish.