Mark on Blonde Naso Tang

[nycpassat]

Appears to be a burn mark on the side of his body which just turned up today. I don't have a heater in the tank. It doesn't appear that it may have hit into a rock or anything since it doesn't appear to be an open wound. It is a little bit lethargic however he is still eating well. Anyone know about this and should I quarantine it?

My water parameters are:

Ammonia: 0
Nitrite: 0
Nitrate:0
Phosphates: .1
SG: 1.021
Water Temp: 72F
150gallon FOWLR tank
Added Seachem Phosguard in a 6x10" media bag two days ago.

I've attached pics for reference. Thanks in advance for your help.

 

[melosu58]

So you are saying that it is just discoloration right now. No open spot.

 

[nycpassat]

looks like he developed some fuzz on the mark now. I think it may be fungus related?

 

[Kurt_Nelson]

Have you recently added any corals? If so, maybe a 'sting' mark? (But that wouldn't explain the "fuzz" you're seeing now, I suppose.)

 

[nycpassat]

Actually i have, zooanthids on a rock and a frog spawn.

 

[Kurt_Nelson]

Hmmm...

I added some zooanthids, waited a week, then rearranged the rock they were on. I think I was a little rough with them as I could see some "stuff" wafting off of them. (I had gloves on, thankfully.)

A couple days after that episode, I noticed a dark spot near the tail of my O.Clown. I kind of looked like the spot on your tang. After researching, I decided it was probably just a reaction to some toxin off the zooanthid - either it went over and tried to host in it, or a blob of the "stuff" that it released found its way to the fish.

I watched it closely, and it eventually just faded away. Like your tank, my fish ate fine during that period, but did seem a little less active than normal. It never developed a "fuzz" though, but maybe the coloration of the fish just masked it, unlike your tang. I didn't do anything to treat my clown. I did feed it some garlic with it's mysis though a little more often than normal. Other than that, I did nothing.

Perhaps your tang got a little chemical "burn" from the new corals?