Yellow Tang Bump??

[GClyde28]

Im somewhat new to saltwater aquariums but Ive had my setup for close to a couple months now. A couple weeks ago I added a blue and yellow tang to the tank. They both did great for the first couple weeks and the blue tang is still doing great but today my yellow tang is not moving much at all to speak of and when he moved from the rock just enough to take a picture i noticed a fairly large bump on him. What could this be?

[Planeden]

Yikes. I can't help you, but you may want to start this in the emergency thread. I'd also change he thread title because it sounded to me like you were trying to "bump" a for sale thread. But maybe that's just me.

Good luck.

[Derek]

Probably just food it ate. Is it eating a lot? It might just be constipated.

[Timfish]

It looks to me like it is emaciated. When you look at it face on you should see a smooth curve across it's face, forehead and onto it's back. If it's back is pinch even slightly so you can see where the skull ends and the back begins a fish is underweight. If you can also see individual ribs it's not doing well at all. An overweight fish will have a notable hump where the skull ends and the back begins which outlines the edge of the skull. A pinched stomach is another warning sign a fish has issues.

[mFrame]

Very odd looking bump. When mine eats you can see the food bulge in his belly. That almost looks like he ate a hermit. How's he doing today? Does he come out at all, only to eat, etc?