Moorish idol attacking CBB

[90gallonreefer]

Yesterday I added a Moorish Idol and a Copperband to my 5ft long 90G reef tank. Everything was fine until I noticed the Moorish idol chasing the copperband and nipping it. Even with the lights off it wouldn't stop. Now my copperband is stressed, it wouldn't eat clams and it sometimes swims sideways. Aren't Moorish idols classified as peaceful fish? Please help me!

 

[TheLadyCrash]

Both fish are considered peaceful fish but they do have a somewhat similar body shape and coloration. From what I’ve read they both should be housed in 150g or larger tanks so they may be stressed out being in too tight quarters.

 

[Humblefish]

Most MIs I've kept have been peaceful; however I thought I had read a thread about one spearing a butterfly with his snout.

 

[90gallonreefer]

Both fish are considered peaceful fish but they do have a somewhat similar body shape and coloration. From what I’ve read they both should be housed in 150g or larger tanks so they may be stressed out being in too tight quarters.

oh. I heard that if I get another idol, it won't fight the copperband

 

[90gallonreefer]

Most MIs I've kept have been peaceful; however I thought I had read a thread about one spearing a butterfly with his snout.

 

[eatbreakfast]

Do not get another MI. Unless they are a bonded pr, MI are intolerant of conspecifics.

I've found healthy MI to be a bit belligerent to other peaceful laterally compressed fish.