Sick Tang?

[Mimbler1]

My yellow tang that I've had for a couple of years is acting nervous today (unusual for him). He spent most of the day hiding behind the rocks, although he would come out to feed with a good appetite. The only symptom I can see is that his two clear fins are both noticeably whitish from the tip to a band about halfway up the fins. It is symmetrical on both left and right fins. Since he is the only fish in a 200 gal reef, the water quality is good.
salinity 35ppt
Ph 8.3
Nitrate, Nitrite, Am 0
alk 9.5 dkh
CA 400

Since he has become quite the pet, any advice would be most appreciated!
thanks, Mike

[Beth]

Wow, that is really something that you've kept this fish by himself. How big is he now?

As you know since you've had this fish for so long, that tangs have to be one of the most skidish fish that there is. It doesn't take much to upset this fish. Is it possible that he was disturbed by an invert: an anemone, crab, etc??

I'd say keep a very close eye on him to see if he calms downs within the next day or so. Give his body the once over, as well. Because he's a solid yellow, sometimes it will be hard to detect visible signs of disease. Really get a good look at his body, fins, eyes, etc., to make sure everything is normal. Look for pearly salt-like dots, red streaks, cloudy eyes, etc...signs of disease.

Have you added LR lately, or LS from an existing tank? Sometimes parasites can hitch a ride on rock and substrate and contaminate your own tank. That is why LS coming from a tank rather than a bag, as well as LR should be QTed before going into your main tank.

Feed your fish food that is soaked in garlic extract for the next week. Garlic is a natural parasite repellent, has a mild antibacterial quality to it and is also an immune booster. If there is a disease process going, the garlic might nip it in the bud.

[Mimbler1]

Thanks Beth,
He's only 4 or 5 inches long - he was tiny when we got him. You're right, he was upset, but not by a crab, etc. Yesterday was tank day, and we replaced lights, blew off the rocks, harvested macro-algae - in short we re-arranged his little kingdom!

I checked the water parameters this morning, and they were fine, so it must have been just the activity. He is acting almost normally this evening, but I can see his front side fins are still not normal. The outer portions are almost clear, then there is a white band, then normal. I'm feeding him extra well with nori soaked with selcon. I'll try adding the garlic tomorrow.

I haven't added anything to the tank for 7 months, so I don't think it could be parasites, but I'll keep a close eye.

Thanks again, Mike

[Beth]

Well, as I said....these are very high strung fish. Don't take it being upset over maintenance events lightly. I would suggest to do less major overhauls by doing maintenance more frequently. Also, when changing out lights, change out 1 bulb at a time, then wait a week to change the other.

Parasites are not likely, but this fish could stress himself to the point of self inflicting a disease, so take that in to account if you want to pamper your fish pet.
:D