Help ID problem w/ orange shoulder tang

[d3rryc]

Hey, there!

I got an orange shoulder tang about 10 days ago. He's about 4", and he's in my 20-gal QT at the moment, sharing space with a dwarf moray. Although the tang only picks at the frozen food, he's hammering the nori. Anyway, despite a 5-min freshwater dip a couple of days ago, he still seems to be flashing and scratching a little, so I just started him on CopperSafe. However, the real mystery to me are these blackish round/oval blotches on his body that WEREN'T there when I got him. I've attached a couple of pictures (of unfortunately low quality - sorry) with the blotches circled in red. I can't find anything in my books or on WetWeb, so any help in getting this identified so that I can start proper treatment would be greatly appreciated.

Water params:
80 degrees
1.026SG
Ammonia 0
Nitrite 0
Nitrate 0
pH 8.2

Filtration is just a little HOB moving about 5X the tank volume an hour.


Thanks much!
Derry

[Bill S]

Not sure. I have a headache from the photos... ;-)

He's eating. That's the main thing with most fish, Tangs especially. Let 'em eat nori!

Personally, I'd avoid additional dips. But, that's me. Feed him/her well, all should go well from there.

[SoLiD]

Your salinity may be a bit too high for a QT.

Check this out from http://www.netpets.com/fish/healthspa/parsalin.html


Parasites and Low Salinity



Below is a Description of How This Method can be Applied :
The method described here involves lowering the salinity of the whole/actual aquarium. I agree that freshwater dipping, (outside the aquarium) or dipping in general, is stressful on the fish, not to mention impractical when trying to net fish in reef aquaria full of rock and delicate corals. Dipping outside the aquaria is also self-defeating (in my opinion), in the fact that it does not kill the free swimming and dormant eggs/spores within the aquaria. You are correct, most parasites are only erradicated within the tank during the free swimming stage.


On the salinity level, I have found an effective treatment level to be 1.017 in reef aquaria. Most corals are safe even lower than this (in my experience), but 1.017 usually does the trick. If I had to recommend a floor for the salinity, I have been as low as 1.015 in reef aquaria. Corals closed slightly directly after lowering salinity, but were open fully the next day, and I noticed no long term detrimental affects in growth rate as a result. I failed to mention before, that if the replacement water is RO/DI or other softened source, then a buffering agent should be employed to prevent pH and alkalinity drops.


It should be noted, that corals on reefs, are often subjected to much lower salinities than those stated above, after heavy rain falls. Especially reefs located near deltas. In extreme cases, corals have bleached (ie. expelled their zooxanthellae, due to osmotic stress), and even died under such circumstances, but in most cases are little affected.


To address sensitive corals, yes there are certain corals which I would have concern with in this treatment (Seriotopora hystrix for example). This category of sensitive corals would extend to Montipora digitata, Pocillopora sp., and other such hard corals generally exhibiting a fine, dense, polyp structure. Acropora sp. has been fine. Sensitive soft corals such as Xenia, lemnalia, etc.. respond little to the lower salinity. Even the hard corals I have mentioned should be fine down to 1.017, (wiith the exception of Seriotopora) as long as pH and alkalinity are kept at normal levels. I have NEVER lost any coral to this method , though the need has not arisen to use this method with the more sensitive hard corals mentioned.


The level at which salinity is at the beginning of treatment is irrelevant, as long as it is dropped slowly. If it is dropped too slowly, the parasites seem to adjust, and initial effect is less effective.


In a fish tank only, I usually recommend a level of 1.012, as was recommended to me by Dave at Aquarium Systems. I have not found any species of fish that responds negatively, and found it the most effective for butterflies and the larger, more senstive angels (most notably Pomacanthus sp.).


Does the lower salinity kill the parasites? I can't say for sure, but the fish seem to exhibit almost immediate signs of relief. Some parasites release from the fish immediately, and others (such as black ich) have discolored, which implies that they may be exploding due to osmotic change. Fish usually resume normal behavior within 24 hrs. By leaving the salinity at the treatment level for at least 2 - 3 weeks, I have never seen an immediate recurrence, which would leave me to believe all the parasites are killed. A customer of mine was the first to try this on a tank full of butterflies and he swears by it to this day. He had been losing fish regularly to Cryptocaryon, as well as Oodinium, for 2 weeks, and suffered no more losses after employing this method of treatment.


All I can offer is that the above mentioned works, and works well. I attribute many a fishes life to this method, and believe it deserves recognition. I would not waste the waste the time in mentioning it if it did not work.

[d3rryc]

Great info, SoLiD - thanks!

[SoLiD]

No problem, Derryc. That's what we're here for.

BTW Please keep in mind that there are tons of answers out there. Some of them will conflict with others. It's still going to be up to you to make an informed decision for your system(s). Just remember, patience and gathering the most knowledge you possibly can, will go a long way into being successful in this hobby. Good Luck. :bigsmile:

-David

[aquasport24]

Mine sailfin tang had the same blotch when i first i got it home from the LFS, but it gone in a week without any treatment.i think that is just a scar from previous injury or ick.

[reeferRob]

My opinion, MY opinion ONLY!!! Temp acclimate it to the temp of the display, and put it in it's home so it get on with life. give it time and Nori. Get it out of all that stuff in the QT, same as for the other animal you have in there. What size are these QT and display tanks? oh 20g QT, I se it Just curious.



Rob

[d3rryc]

I'm just terrified of introducing a sick fish to a 140-gal reef tank with about 120 lbs of live rock to hide in and about 10 small- to medium-sized fish possibly to infect. I can't fit everyone in the QT, and I don't want to wipe out all of my fish stock - been down THAT road before... Giau's comments are encouraging, and the blotches SEEM to have gotten a little lighter, but they weren't there at all when I first bought the fish. I think I'm going to hunker down and keep it in QT for a bit longer, while throwing all the nori at it that it can handle.

Still chasing a firm id on those blotches, though...

[reeferRob]

LOL yeah most people don't take that advice but it has rarely let me down. I see the whole QT thing as more stress and prolonged stress. I know I could wipe out all one day but so far I've been lucky. I'll keep my fingers crossed. Aggression is the biggest killer in my tank when adding a new tankmate.

Sorry I couldn't help ID that spot, maybe someone could get you a better pic.