View Full Version : Yellow Tang Fins Deteriourating

02/18/2017, 07:05 AM
Anyone know why yellow tang fins sometime recede? This one has been in the tank for a few months and began to look like a nip out but has continued to recede since. The tank is 2 year old 180-gallon reef with acceptable parameters. All other fish and coral are healthy.
Diet is frozen freshwater PE mysis and Nori. I have noticed this a few times with other yellow and purple tangs in other aquariums also.

Any insight appreciated


02/18/2017, 08:13 AM
Could be fin rot

Vinny Kreyling
02/18/2017, 08:26 AM
I have seen Lateral Line Disease do this.

02/18/2017, 08:53 AM
my tang sleeps on the ground in between the rocks in back of my tank..and have almost the same look as your ...i beleive the crabs are picking on mine since hes so close to ground..maybe thats what you have as well...hmmm

02/18/2017, 10:32 AM
Not tail rot ... it is the only fish effected and have them doing the same thing at other locations. But only the yellow and purple tangs. Sometimes it does seem to show a deterioration of the slime coating and perhaps scales around the lateral line. Don't believe it is from tank mates as it does not erode with sharp edges. All the deterioration looks smooth, like it was burned off. It also does not grow back. I have seen this progress until the fish looks like it has a triggerfish dorsal (just first couple rigid rays remain)

NO3= 20 (I know, I'm working on it)
PO4 > .1
pH <7.8

Thanks for the feedback

02/18/2017, 10:35 AM
I'd advise treating with a broad spectrum fungicide and antibiotic. There is absolutely no way to diagnose stuff with just a photo (heck half the time it can't be dosed when observing it in RL), so it's best to assume the worst and treat aggressively.

Sounds Fishy
02/20/2017, 06:46 AM
Are you running Carbon?
I had a yellow tang,develop what I thought was Hole in the Head disease,(unconfirmed)which I remedied with removing carbon from the system.He got to the point where he wouldn't emerge from the LR. It was loosing his dorsal fin(it would get white,then atrophy at the top of the fin,then erode,in one area,primarily)After the carbon was removed,he made a complete recovery.All of the deterioration,reversed itself.I never removed it from the display tank,and did not treat it,with anything.At the same time,another yellow tang,in the DT,never became ill.

02/20/2017, 08:14 AM
I agree with the LL Issue.. But Check the tank for Stray Voltage as well.. I had this happen to a Tang in qt and found out that the heater in there was leaking voltage...

elegance coral
02/22/2017, 06:11 AM
It is clearly HLLE. The whole fish is pale, but especially around the eye, and the lateral line is white, and clearly visible.
I would keep nori in the tank 24/7, and maybe look into a vitamin additive like selcon.

02/23/2017, 08:00 AM
A little more variety in what you are feeding couldn't hurt either.

02/24/2017, 10:14 AM
Stray voltage causes this as well. I would put insert a grounding rod into the sump. Do you get a shock when touching the water and making contact with metal?