Will kole tang aggression subside?

[dbleoh7]

I added my last tank inhabitant, a blue mandarin. My 3 year old kole tang all of a sudden became super territorial throughout the entire tank and has pushed the mandarin into hiding in the corners of the tank and the mandarin isn't eating because of it. It's the first time it has ever exhibited aggression towards another fish. Should I give it another couple of days or will it mostly persist? I've kept the tang well fed and have tried the mirror trick but it doesn't work. I can't rearrange the rockwork and catching the tang would be a nightmare/borderline impossible. It's a 48" x 22" x 14" (L x W x H) tank and it has apparently claimed the entire tank as it's territory. I'm debating on putting the mandarin into my 10 gallon temporarily and giving it away to another hobbyist if it will continue.

 

[Fish Think Pink]

I added my last tank inhabitant, a blue mandarin. My 3 year old kole tang all of a sudden became super territorial throughout the entire tank and has pushed the mandarin into hiding in the corners of the tank and the mandarin isn't eating because of it. It's the first time it has ever exhibited aggression towards another fish. Should I give it another couple of days or will it mostly persist? I've kept the tang well fed and have tried the mirror trick but it doesn't work. I can't rearrange the rockwork and catching the tang would be a nightmare/borderline impossible. It's a 48" x 22" x 14" (L x W x H) tank and it has apparently claimed the entire tank as it's territory. I'm debating on putting the mandarin into my 10 gallon temporarily and giving it away to another hobbyist if it will continue.

+1 vote remove one of them

Wouldn't think mandarin would spark tang territorial behavior, so this was an eye opener for me. When my first territorial episode happened, I didn't think I could catch aggressor either. Death inspired me to get better. Multiple deaths inspired me to get even better. What you think you can't do today, perhaps you'll do with ease in the future.

I now have multiple sized IceCap fish traps and multiple acclimation boxes, favorite being The Shu acclimation box by Octo Aquatics. Its my favorite due to magnets that let me move it into all territories of my tank, up down side to side so new fish will be allowed to visit everywhere... but after 2 weeks in box new CBB fish in box still being attacked by tang, sailfin went to sump. With sailfin in sump, released CBB and my other Death Dealers left fish alone!

CBB and sailfin stripes are so similar think sailfin will never accept a CBB, so we made the hard decision and rehomed our sailfin yesterday to LFS for wholesale credit. They had another there and our sailfin was so much healthier so I know he'll get a good home. I passed along all his preferences so they can let next owner know. If it hadn't been a CBB I was introducing, I know it would have worked out for us (though, no death 2 weeks in so did work out), so I'm hopeful for you too

Hoping it all works out for you!

 

[Dolphins18]

Kole tangs are like this when they are dominant, mine killed many fish, did not matter what fish it was until he went into a bigger tank where purple tang made sure he knew who was boss.
Seeing that you shouldn't have another tang in that tank, I would recommend removing him and waiting until you have all the fish you want established before adding another bristletooth tang.
You do not need to move rock work to catch him, this will do fine https://www.saltwateraquarium.com/small-acrylic-fish-pest-trap-6-x-4-x-4-generic/

 

[dbleoh7]

Kole tangs are like this when they are dominant, mine killed many fish, did not matter what fish it was until he went into a bigger tank where purple tang made sure he knew who was boss.
Seeing that you shouldn't have another tang in that tank, I would recommend removing him and waiting until you have all the fish you want established before adding another bristletooth tang.
You do not need to move rock work to catch him, this will do fine https://www.saltwateraquarium.com/small-acrylic-fish-pest-trap-6-x-4-x-4-generic/

So if I am able to remove him for a few days then put him back in he will likely be less aggressive toward the new fish?

 

[Fish Think Pink]

So if I am able to remove him for a few days then put him back in he will likely be less aggressive toward the new fish?

if you remove him for 2 or ideally 3 weeks (not days), then yes you may break territorial hold. Some find it takes even longer

 

[DeniseAndy]

If the tang is eating well, set a trap. They go in. At least mine always have if I needed to pull them. The only fish I could never catch was a huge blackmouth chromis. Got 4, not the fifth. Smart fish.

 

[Dolphins18]

I mentioned removing him altogether for now because I thought there may be more fish you want to add in coming months, the Kole tang will do this for most all fish added. If you are content with not adding more fish, removing it for 2- 3 days will likely work well for the fish in the tank. If you'd like to add more it would be wise to remove it and replace it at a later date.

 

[dbleoh7]

I mentioned removing him altogether for now because I thought there may be more fish you want to add in coming months, the Kole tang will do this for most all fish added. If you are content with not adding more fish, removing it for 2- 3 days will likely work well for the fish in the tank. If you'd like to add more it would be wise to remove it and replace it at a later date.

Yeah the mandarin is the last fish I'm adding. I moved the mandarin out to my 10 gallon for now and bought a bubble fish trap. Hopefully I can put the mandarin back in once the tang is gone and then put the tang back in a few days later and everything is fine

 

[vic5hands]

Yellow eye or Blue eye Kole .. My yellow eye couldn't care. My Blue eye watch out I'm coming for you

 

[dbleoh7]

Yellow eye or Blue eye Kole .. My yellow eye couldn't care. My Blue eye watch out I'm coming for you

Yellow eye. Never showed even a tiny sign of aggression until the mandarin was put in. I assume he was threatened because the mandarin is a XL. He’s a big boi

 

[dbleoh7]

Well I used the bubble trap to take her out. I moved her to a 10 gallon for 6 days and reintroduced her. She's actually behaving now and everything is peaceful again.