Clown fish randomly started attacking sailfin tang

[saltytech]

So I have had a mated pair of ocellaris clowns for almost 11 years now and they have been house alongside my sailfin tang for nearly 9 years. The tank has changed a lot over the time but they have never shown any aggression towards each other. 4 months back I upgraded to a 180 from a 150 and in the last couple weeks the female clown has been attacking the much larger sailfin and essentially forcing him to stay on the far side of the tank. The clowns did just lat eggs but they have been doing that every 2 to 3 weeks since I can remember.

Another thing to note is I added a copperbanded butterfly recently that caused quite a stir with the tangs so I added egg crate to separate them and within a day they were all good with each other.

Anyone with any ideas on how to curb this aggression?

I have had these fish for too long to just give up and get rid of him.

https://flic.kr/p/2hqb2zq

Thanks!


Stock list:
Blonde Naso Tang
Sailfin Tang
Yellow Tang
Clowns
Damsel
Chromis
Filefish
Copperband Butterfly

 

[Skycraft]

I’m having the same issue, what was the problem? I just added a sailfin tank and the clown fish started to attack it as soon it got to the middle of the tank, it kept attacking it till the sailfin tang goes to the side of the tank!

 

[JohnL]

I’m having the same issue, what was the problem? I just added a sailfin tank and the clown fish started to attack it as soon it got to the middle of the tank, it kept attacking it till the sailfin tang goes to the side of the tank!

Welcome to Reef Central. What kind of clownfish?

 

[kharmaguru]

Sounds like normal clownfish/damsels - territorial jerks. Add last.

 

[Sugar Magnolia]

I’m having the same issue, what was the problem? I just added a sailfin tank and the clown fish started to attack it as soon it got to the middle of the tank, it kept attacking it till the sailfin tang goes to the side of the tank!

What size is your tank?