Regal Hippo Color Change

[fio1022]

Hi,
I have a Yellow Belly Regal Blue Tang (Paracanthurus hepatus var.)
that was the size of a half dollar when purchased.I was told from LFS ,that as he matures he will develop the yellow underside.
He is now about 4+inches and has always had very vibrant colors until recently.
Does this look like a normal color transformation?
Behavior and appetite seem very normal.

These two pics taken today
http://i7.photobucket.com/albums/y255/fio1086/IMG_1453_zps76aa1e5e.jpg (http://s7.photobucket.com/user/fio1086/media/IMG_1453_zps76aa1e5e.jpg.html)

http://i7.photobucket.com/albums/y255/fio1086/IMG_1449_zpsb392c6a2.jpg (http://s7.photobucket.com/user/fio1086/media/IMG_1449_zpsb392c6a2.jpg.html)


This picture taken August
http://i7.photobucket.com/albums/y255/fio1086/IMG_0127_zps98430fd3.jpg (http://s7.photobucket.com/user/fio1086/media/IMG_0127_zps98430fd3.jpg.html)

[Ross33]

Are you feeding plenty of nori? Looks like it could be the start of HLLE. Very common in tangs and angels when they do not have enough nori.

[fio1022]

That doesn't sound good.
I do feed nori just probably not as much as i should.
Is this reversible?

[Sugar Magnolia]

Yes, but if left for an unusually long time, it can leave scars on the fish. Have a look here - http://www.reefkeeping.com/issues/2005-06/sp/

[ca1ore]

I've never seen HLLE manifest itself as a pale blotchiness though? How long have you had this fish? Has anything changed in your tank recently, like new fish, new lights, tank move, etc.? Any white, stringy poops?

My hippos would go all pale and blotchy when they were stressed, particularly when I moved my tank. Looks like some kind of stress reaction to me.

[phoenixstar89]

That doesn't look like hlle to me. My yellow belly hippos do something similar to yours except mine will change their entire black section to a white/gray color and then change back black. Hippo tangs don't need as much algae in their diet as all the other tangs so I wouldn't worry too much about the nori. I got mine smaller than yours and they've only ever been fed nls pellets and mysis and they are very healthy.

[MDO]

Color is fading. That is usually due to diet and stress. What major changes have you made since August?

[fio1022]

Thanks for the replies.
I can't really pin point any major or minor changes.Things have been pretty stable lately.
I'm going to start adding vitamin c and garlic to his food.Hoping for the best.
He does seem healthy and happy so far.