Tang Aggression

[frydaddy]

Had a fowlr up for a long time. About 4 years ago I added a small yellow tang. Over the last 4 years the number of fish in the tank has decreased until 3 months ago when it was down to a diamond goby and the tang who is about 4". Tang had always been a model citizen. About a week ago my LFS had a very healthy fat 5" Aussie Tusk which is a fish i've always wanted so I got him. When I introduced him to the tank, the tang went ballistic. So i caught the tang, moved him to a QT tank. Bought some more rock and completely rearranged the rock work adding as many caves and levels as possible. After a week, I readded the tang. He once again went after the tusk to the point he keeps him pinned in an upper corner of the tank. I heavily feed and always have nori on a clip. Any other ideas for reducing the aggression? Hoping to keep both fish and add a few more down the road.

 

[Lost in the Sauce]

That's a tough one as you've already done what should have worked.

Do you have a large enough acclamation box that the yellow tang can hang out for in a few days, in the tank getting used to the new fish?

Adding multiple fish at the same time usually helps dispell aggression, But in this case I'm not sure I would advise that.

 

[frydaddy]

Don't have a large enough acclimation box. Thought of adding another fish like an angel, but would have to go through QT first, so would be weeks away to see if that's a solution.

 

[exnisstech]

Maybe build a box out of egg crate and zip ties?

 

[frydaddy]

Yeah, that might be worth a try, might be possible to build an egg crate wall and section off part of the tank.

 

[bobnicaragua]

I know I’m a bit late to the party, but putting a mirror in front of the tank will give the established tangs something else to focus on, at least some of the time.

 

[Fla B]

I have a Yellow tang and just added Powder Blue tang. I hang a mirror on the center of my tank. The Yellow will attack the glass where the mirror is and gives the new tang time to get acclimated. I keep the mirror up for a week or so. so, after that everything is typically okay

 

[bobnicaragua]

I was just able to add a sailfin tang in with my dominant purple tang. The purple tang hated the sailfin, but he hated his own reflection more.

The sailfin got a little beat up, but I kept the tank well fed and he healed quickly.

 

[YOYOYOReefer]

so wierd ,my tusk rules the tank,

 

[4FordFamily]

"Only tang syndrome" as I will dub it, is a bit unique. When tangs are used to being the only similarly-shaped herbivore in a tank, they tend to be less inviting of "guests". In their heads, they've successfully kept their territory free of herbivores.

In this case of course, a tusk is hardly an herbivore, far more carnivorous although mine eats anything. But this can also apply (sometimes even more so) when there are fewer other fish in a tank. They get used to being "alone". The goby occupies a completely different area of the water column, thus he's not seen as a threat. The tang is also used to its' presence.

In short, adding multiple fish at a time can prevent/reduce this type of aggression. Thankfully, zebrasoma tangs (as yellow tangs are) GENERALLY do not hold long grudges against newcomers unlike some of their acanthurus cousins (such as powder blue, achilles, clown, and sohal, and powder brown to name 5 bad offenders). Sometimes they can eventually even accept conspecifics. I find that they're the least likely tangs to continue to be territorial (after say 2-3 days). Of course, individuals vary and he's been able to get used to ruling the tank without much influence.

A mirror is probably a great distraction. I am a bit surprised the moving of the rocks didn't work, but I think it's addressing perhaps the wrong problem - in that the issue is he doesn't want to share his space. I think it will blow over fine.

When I add new fish, especially tangs - I notice the dominant tangs torment newcomers. Typically this doesn't last long. If the fish is healthy, eating, and can get away from the attacks, it should work out. They will slowly become more acclimated. Harlequin tusk are sometimes fragile at first, but if quarantined and acclimated to aquarium life I find them to be QUITE hardy and eventually ornery. If the yellow tang doesn't stop pushing its' luck, the tusk will probably make his/her point clear that the bullying ends. Hopefully the YT survives that encounter if it happens.

My bet is that in 2-3 days if the tusk can handle the stress/bullying, all will calm down significantly and peace ensues shortly thereafter.