Yellow Tang attacking smaller Scopus Tang

[andrejk]

I’m moving from a 120gal to a new 170gal (see my build thread) and moving what I thought where a peaceful group of fish over. It’s been fine for the two week or so since I moved them over in groups but now I have a problem.










Today I saw the Scopas hiding above the wave maker. When I waved my hand in the area to make him move, I noticed damage on his fins and then saw the Yellow go after him. The Yellow was in the old tank for 4-5 years and the Scopas for about 2 years. I always thought the Scopus was shy because he was often hiding but he came out to eat and I never noticed any signs of trouble.

So now I have the Scopas in a box to keep him safe for the moment. The Yellow is aggressively patrolling, probing every side of the box. I’ll watch what happens over the next day or two.

I’d like to find a way to reintroduce him. I could build more small hiding places where the Scopus could hide but maybe that was never a good situation for him in the old tank.

Maybe he needs a new home?

Any advice?

 

[RichReef]

Use a mirror. It works. It really does. Use it before reintroducing the small guy.

I have a Purple, Sail, Powder Blue, Yellow and a Kole. They are thick as thieves. Move like a school. There is zero aggression. Anymore.

All because of a mirror. A week is usually all it takes. Once they realize the other doesn't actually look like them they stop aggression. This has only worked on tangs for me. It did nothing for clown, chromis, or damsel aggression.

 

[BonnieB]

My yellow is being aggressive with a smaller tang. We’ve tried to get one of them unsuccessfully. I’m going to try a fish trap next but if that doesn’t work then I’ll have to tear down my rock work. One of them has to go to the other tank! Good luck with yours. I feel your pain

 

[larrysaltisfun]

I completely agree about using mirrors at each of end the tank my Scopas tang spent the day striking himself. instead of the purple tang that I just introduced. Also, I would swap them out and put the yellow tank in the acclamation
box and let the Scopas tang have the run of the tank and then introduce the mirrors before the yellow is released .

 

[andrejk]

Wow I added the mirror and I’m amazed at how much the tangs are engaging with it.

View attachment 20260214_202656_3CDD11EC-1F85-49B4-8820-090ACCAC963F.mov

They swim up, flair out their fins and whip their tails.

The Scopas is healing up nicely in the acclimation box. I may give it another day and see how it goes. If I have to, I’ll make a larger acclimation box that covers a corner of the tank to the surface so it’s easier to feed and the Scopas has more room.

 

[andrejk]

The Scopas is healing up nicely from his fin damage and scratches.

I just released him from the isolation box and all is good so far! Now he’s in the mix with the other tangs in front of that dang mirror. It’s amazing they this easy cheap idea has totally changed their behavior. I’m also feeding extras to keep everyone content.

I’ll watch them closely for a few days — hopefully they stay happy. Thanks for the great advice!

 

[andrejk]

Amazing how quickly they recover! This is 2 days

 

[larrysaltisfun]

Glad to hear your tangs are getting along, but it looks like your scopas may have ICH or maybe it’s just mucus cones, but as the fish medics will tell you very often ICH is mixed in with Mucous cones. They can be caused by stress. Even if it’s only mucus cones , they will likely recommend treatment to be safe

. I would definitely post this on the FISH DISEASE AND TREATMENT Forum and let Vetteguy Jay Hemdal, MNfish and W31olds look at this and get their opinion.

 

[69cam]

My yellow is being aggressive with a smaller tang. We’ve tried to get one of them unsuccessfully. I’m going to try a fish trap next but if that doesn’t work then I’ll have to tear down my rock work. One of them has to go to the other tank! Good luck with yours. I feel your pain

When I need to to remove a fish from my tank, I just drain the tank down to about 4-5 inches of water and don't touch rocks, works very smoothly every time.

 

[andrejk]

Glad to hear your tangs are getting along, but it looks like your scopas may have ICH or maybe it’s just mucus cones, but as the fish medics will tell you very often ICH is mixed in with Mucous cones. They can be caused by stress. Even if it’s only mucus cones , they will likely recommend treatment to be safe

. I would definitely post this on the FISH DISEASE AND TREATMENT Forum and let Vetteguy Jay Hemdal, MNfish and W31olds look at this and get their opinion.

Thanks for taking a close look! I see what you’re saying. Those white dots are on the box, not on him.

I lost half my fish 4 years ago with a horrible ich outbreak, so I’ve seen how that looks in the later stages. (I naively bought a powder brown tang without quarantine and he spread it to every fish in the tank).

Here’s a picture of him now outside the box. He looks pretty clean to me as do the other fish. But please lmk if I’m missing something. I know these things can spread quickly if you miss the early signs.

 

[larrysaltisfun]

That’s awesome to hear. nice Naso BTW

 

[andrejk]

He’s my fat hungry boy — he’s good at feeding the coral