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FAQs on the Powder Blue Tang Pathogenic Disease  
(plus see Tangs/Rabbitfishes & Crypt)

FAQs on Powder Blue Tang Disease: PBT Disease 1, PBT Disease 2,
FAQs on Powder Blue Tang Disease by Category: Diagnosis, Environmental, Nutritional, Social, Trauma, Genetic, Treatments

Related Articles: Powder Blue Tangs, Acanthurus Tangs

Related FAQs: Powder Blue Tangs 1, Powder Blue Tangs 2, Powder Blue Tang Identification, PBT Behavior, PBT Compatibility, PBT Selection, PBT Systems, PBT Feeding, PBT Reproduction, Acanthurus Tangs 1Acanthurus Tangs 2, Acanthurus Tangs 3, Acanthurus ID, Acanthurus Behavior, Acanthurus Compatibility, Acanthurus Selection, Acanthurus Systems, Acanthurus Feeding, Acanthurus Disease, Acanthurus Reproduction,

One of a few Tang species that is VERY susceptible to Protozoan infestations

Surgeonfishes: Tangs for  Marine
Diversity, Selection & Care

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by Robert (Bob) Fenner

Trying to save my fish; CP f'      9/10/17
I had a group of 5 fish (juvenile Queen, an adult Imperator, a Powder Blue and Achilles tangs and a smaller Blue Jaw Trigger) in my 160 gal QT system, made up of 3 - 55gal tanks plus sump. They have been there since Aug.
12th. They seemed to be doing good at first. They were in lower salinity water for over two weeks ~ 17ppt, temp 78F, pH around 8. I started to slowly bring the parameters up to match my display when I saw Ick break out on the Tangs.
<Very common; as you likely know these two Tang species are VERY susceptible>
I lowered the salinity back down to 17ppt and did 2 treatments of Chloroquine Phosphate (from National Fish Pharmaceuticals) . After a week the trigger died. The Ick seems to have morphed into Amyloodinium
ocellatum - cloudy eyes, shedding slime, patchy white on the Achilles...I'm not sure if the darkening pelvic fin is on the Powder Blue is a symptom of something else.
<Could be sampled, looked at under a 'scope. Perhaps just chemical/physical burn>
The tangs have stopped eating.
<VERY bad>
The two angels are still in better shape - I only see white spots on the eyes and they are still eating well. I gave both tangs a fresh water dip yesterday but didn't see any improvement. I pushed the salinity lower to 14ppt. I am about to do a 25% water change and give another treatment of Chloroquine. Am I missing something?
<The CP may be hurting more than helping here. >
Is there something else I should be doing? Here are some pictures.
<IF these were my fishes, I'd NOT use the quinine, but just drop the spg.
down to 1.010, and hope. They may be too impugned to come back at this point>
I would appreciate any suggestions you might have Thanks,
Mike Spizzirri
<I would have you read re others experiences w/ CP (on WWM) as well. Can be tricky in use: http://www.wetwebmedia.com/QuinTrbFixF.htm
and the other Quinine FAQs files linked above. Bob Fenner>

Powder blue tang; hlth, using WWM      6/24/15
I am facing a concerning issue with one of my favourite fish. I have recently put my pet in QT and commenced hypo with him after some concerns he may have been infected by ich.
<Very common w/ this Acanthurus and a few others... READ on WWM re>
He has been in hypo
<Rarely effects a lasting cure. READ re this as well>

for two weeks and eating up to three days ago. He has great colour, is thick and his fins are perfect. The problem is he is struggling to swim. He is constantly at 45 degrees or worse and swimming almost in circles with his head up.
<Could be simply the low salinity>
The salinity is at 1.009 and the other fish is in QT with are doing great. I am considering treating for bacterial infection with something like Kanaplex
<Mmm; I wouldn't... for reasons again gone over and over on WWM>
but wanted to ask what you thought I should try.
<Reading... likely the use of a Quinine compound... these fish are still Cryptocaryon (et al. likely) hosts; just being weakened further through the hyposalinity treatment... Seen this many times; avoided buying the tee shirt, no news at eleven>
Thank you for you time and any guidance you can provide.
<Simply the looking, reading, understanding ahead of real action through the use of WWM's archives. Bob Fenner>

Powder blue tang 4/8/13
Hello all. My powder blue tang has what looks like small white threads on one of its eyes.
<Ahh, likely Trematodes... Flukes>

Tried to get a pic but to no avail. Tank info - 125 gal, 100 lb live rock, ammonia, nitrite, nitrate all 0 - ph 8.3, temp 77 degrees. Fish in tank - yellow tang, clown, flasher wrasse, royal gramma, lawnmower Benny, red Hawkfish, long-nosed Hawkfish (all get along fine). Any thoughts?
Diann Trapp
<Search WWM re. Bob Fenner>
Re: Powder blue tang 4/8/13

Thanks, any suggestions as to what to do? He's eating like crazy and acting normal. Should I be concerned about other fish?
<... please read where you've been referred. BobF>

Powder Blue Tang and parasites, parasitized sys. 10/22/08 Hi, <Marcia> I have yet another question for you about powder blue tangs and parasites. I bought my PB tang about three months ago. He is housed in a 55 gallon tank. <... too small> (Yeah, I know. The arrangement is temporary. I'm setting up a 130 for him.) <Likely should have waited> Tankmates include a pair of gold head sleeper gobies, a small damsel, a small algae blenny, a few small hermit crabs, and a sea urchin. Tank is well established, has a 4+ inch sand bed and a moderate amount of live rock. Ammonia, nitrites, and nitrates are negligible, pH 8.2, temperature 81, salinity 1.022, <Too low...> lots of water movement. I did lots of reading before buying the tang, so I pretty much knew what I was getting into with this fish. He was the last fish added to the tank, and I do not intend to add any others. I am feeding mysis shrimp and two kinds of Nori. Food is soaked in garlic. The tang was in good condition at time of purchase. He eats well, is full-bodied, and still has lots of "sparkle." <Good> Of course, I knew it would likely happen sooner or later. One morning I looked, and the PB tang had several spots of ich. A few days later, he began to have tiny bumps all over his skin. Today I noticed a few gray spots (~2 mm. diameter) on the anal fin and the body in that region. It seems to me that the bumps and the white spots are different stages of the same thing, but the gray spots are not something I have not seen before. Possibly a secondary disease? <Define "disease"...> So here's my question. Assuming the whole problem is parasitic, <Is not... a large part/element of "the whole problem" is environmental> is it possibly to control disease like this in the main tank effectively, without using medication? <Mmm, yes> Shortly after the fish began to show symptoms, I added a UV filter to the system, hoping that that would help. <A bit... to improve water quality> The parasites continued to multiply. Since then, I have added a diatom filter with an 800 gph pump. <Shouldn't be run continuously> It is my understanding that the diatom filter does help with ich, but do you think it could arrest the outbreak once it is in full force? <It cannot> The UV filter continues to run as well. I do not have a hospital tank set up at this time, and I do not really have the financial resources to buy much new equipment right now. Can you make any additional recommendations? Marcia <Yes... read here: http://wetwebmedia.com/parasittksfaqs.htm and the linked files above. Bob Fenner>

Powder Blue "pimples" 7/3/08 Hi and happy 4th of July to everyone at WWB. <?> I'm writing in regards to a problem I have with Peanut, my Powder Blue Tang. I bought him a little over a month ago and immediately put him in a 40gal QT. I observed him for a period of 3 weeks and I didn't notice any problems, no parasites, no signs of disease, eating frozen food and the dry algae sheets. The fish is about 4 to 5 inches in length. Then I thought everything was great and put Peanut in my 150gal FOWLR. He acclimated very well and none of my other fish bothered him. If anything he bothered my Foxface at first, but then they became friends. A week later however, I noticed something very odd. He had what looked like pin sized pimples all over his body. They were not white like ich and it looked like they were under the skin. He didn't seem bothered, still very active and eating like a pig. I waited hoping these "pimples" would go away but they didn't so now Peanut is back in the QT, except I have no idea what is wrong or how to medicate for this problem. If these pin sized pimples were white, I'd say ich, although none of my other fish have it and the tank has been ich free for 6 months. Still, anything is possible. Any idea what these are? They're only on the body, nothing showing up on any of the fins. My tank parameters: Ammonia and Nitrites: 0 Nitrates: 20 pH: 8.3 Density: 1.025 Other tank mates: 5" Foxface, 4" Picasso Trigger, 4" Niger Trigger, 4" Yellow Canary Wrasse, 2" Juvi Queen Angel. Again, there was no aggression at all. The Niger is the most aggressive in the tank but it never bothered the tang. Thanks, Peter <Mmm, likely sporozoans... not easily treated... Could be encysted worms... these might be treated with a vermifuge. Bob Fenner>

Microsporidean Infection - Will it go away? 3/21/06 Hi Bob, <Steve> You have been such a great help! I recently got a small Powder blue tang that has been showing pimple-like bumps on its body - not salt grains (ich) and not dust-like (velvet). After researching your site, I'm pretty sure it's a microsporidean infection. My question is, while it is said that there is no cure for this, will it just go away or is the fish just doomed? <Mmm, have seen such infestations live "with their host" for many years> In your responses to the other related posts, you only mentioned that it's not infectious to other species nor is contagious. Secondly, how long does it usually take for these bumps to develop? <...?> I'd like to figure out if it picked it up in my tank or already had it when I bought it from the store. <This latter, assuredly> I bought the PBT with a yellow tang at the same time so that they won't get too territorial. For the first few days they were buddies, then the PBT would get annoyed and they'd flash their tails now and then. Could these bumps be coming from stress maybe? <To some extent> Also, from your experience, how long does it take to go away? <Sometimes months, other times, never.> thanks again for your help. You've truly impacted the aquarist community for the better. Steve <There are some groups of fishes, my favorite example the serrasalmine fishes called Silver Dollars, that very often have these... and they often prove persistent. I would enjoy this fish, ignore the bumps. Bob Fenner>
Re: Microsporidean Infection - Will it go away? PBT dis. - 03/22/06
Update on my PBT - Last night the white bumps turned into more or less white specks and white specks started showing up on its pectoral fins. <Is likely the protozoan Cryptocaryon...> Then this morning they looked black on the body but still white on the fins. As this is my first time dealing with this, I find myself second guessing my initial diagnosis. Could it be ich, <Most likely> or black ich that I'm seeing instead of a microinfection or is this just part of the lifecycle for the microsporidean? The fish is less active today and swimming a little more wobbly but still eating Nori and picking at algae on the LR. His original darker full blue has faded into a much lighter powder blue and he's not picking on the other fish anymore, sometimes just hiding in the corner away from the other fish. Sorry for bombarding you guys with these trivial questions - I feel like a nervous parent who's never seen their kid have a cold before. So a little reassurance or at least understanding of what's going on would be most helpful. Just in case, since I only have a 10 gallon QT, I decided to move all my corals (I don't have that many, just some zoos, xenia, anemone, and candy cane) to the QT and leave the fish in the main tank with a some live rock in case I need to medicate. Did I misdiagnose or is this just part of the microsporidean lifecycle and I just have to wait it out? Steve <... is not likely a Microsporidean. Please read here: http://wetwebmedia.com/powdbluetg.htm and the linked files above. Bob Fenner>

Powder Blue Tang... dis., sel....  08/27/07 Good Mooring, I'm so glad that there is a resource for advice about marine fish, thank you! I have a powder blue tang that I moved to quarantine 7 days ago because he contracted ick. <Mmm, a mis-statement, perhaps misunderstanding... this fish did not contract such... it simply expressed what it already had/has. Further, it's not in a quarantine setting, but a treatment one... lastly a note/hope... that all fishes in the previous system are under treatment, as assuredly all and the system itself are infested> I'm treating the water with Copper safe and after 3 days all signs of ick were gone. <Uh, no... just cycling to another generation> Today the 7th day I noticed he seemed irritated, swimming back and forth fast, restless, rubbing his body on the power head. I'm concerned about copper poisoning so I did a 20% water change and added carbon to start removing the copper thinking that this might be the source of his irritation combined with his irritation of being in a 29 gallon tank. <Maybe... but...> He is only about 3 inches <Total length? Undersize from what I consider ideal to start> but has always been a very active fish. He eats Mysis and Spirulina soaked brine without a problem. <Good> In the main display there is tones of live rock and plenty of macro/micro algae for him to eat. Right now I'm concerned that his dietary requirements are not being met in quarantine. He barley <I like this as an ingredient in beer, barely> notices the macro algae that I offer and has never gotten to were he would eat the dried seaweed that I add. <Takes a while...> I feel good about this fish in general. But, because his stress level is increasing in quarantine I want to add him back to the main display in a couple of days or sooner but I know that he has not been in quarantine long enough and the main display has not gone fallow. <You'll learn...> The other inhabitants have not shown signs in a week and I removed him with in hours of his first symptoms, once I was sure it was ick and not fish slime stuck sand. I know this fish is prone to ick. <Oh yes> And because of that I know my main display will be subject to it as well. Do you feel that putting him back in the main is the wrong move at this point even though he has a better food source and lots of room to roam or worth seeing if his natural immunity will kick in and help him fight any major out breaks of ick like he other fish, I do have two cleaner wrasses and two cleaner shrimp to help out. <A possibility...> The cleaner wrasses are so used to being fed that they are not aggressive cleaners. <Good> At this point all the other fish are OK and I do not feel that they need to be taken out and treated unless one comes down ick and that really seems unlikely to me. <Only time, experience, reflection can/will tell> I just don't want to make the wrong move <Too late> and I'm finding that I'm a little nervous with him because of the history with powder blue tangs. I guess my main concern is that even though he eats the food that I'm giving him I'm noticing some weight loss and he is not able to graze and that is such a major thing with this fish. Thank you, Mark <Up to you to make the general "trunk" choice of returning the PBT... I do hope that this is the last fish to be added... that in future stocking you'll take the time to read, do prophylactic dips/baths at least, quarantine incoming fishes... Good luck here. Bob Fenner>

Powder Blue Greetings Crew, Thank you for taking the time to read and respond to this. I have had a powder blue for about 8 weeks now. I initially had him in a quarantine tank for about 4 1/2 weeks. All seemed to be fine. I put him in the main tank and he was doing well. About a week and a half later, 1 day after I come back from a short two day trip, I see white spots on him. My tank is a 60 gallon reef with 20 gallon sump. I have a clownfish, springeri pseudo, and a coral beauty. The salinity is 1.021-.022 and the temp is 79-81. I have about 75 lbs of live rock. One possible change may have been due to using a dripper to drip in water that evaporates while I was gone. It is hard to control the dripping rate and there have been times when the control loosens and the water drips in way too quickly, possibly resulting in changes to the salinity. I don't know if this is what happened, but when I got back, the dripper was almost empty.  Anyhow, the following day, after I saw the ick (spots along with bumps), I decided to take him out and put him back in quarantine. I first gave him a freshwater dip with a buffer and Meth blue for about 15 minutes. Might have been too long? <<To which you respond?>> He seemed to be fine afterwards and for the next week, he has shown no signs of ick. I have been doing water changes every 2 days. The quarantine is 10 gal with sponge filter, heater, one powerhead, and one piece of live rock. I have Gracilaria algae in the tank and I feed him frozen food ranging from form 1, Hikari Mysis, ocean nutrition brine shrimp plus, and prime reef frozen. I did not get to take a look at him last night as I came home late but this morning when I took a look, he had a couple of white spots and he had black spots all over. I did some research on your site and read about black ich common to yellow tangs. One question I have is, is this probably black ich on my powder? <<Well?>> There were spots on his fins and body (looks like freckles). I understand that black ich comes from some kind of worm. Does this mean that this parasite was in my quarantine tank or from my main tank? <<?>>  I have had my main tank for a year and a half and have had no such signs. I also read somewhere that you should remove the fish into another system from which that parasite may be.  However, since my powder is already in my quarantine and I don't want him in the main tank infecting my other fish what can I do? <<James? What would you do?>>  I ended up giving him another fresh water dip for 8 minutes this afternoon and then did a water change. The black specks seemed to have disappeared although I can still see them on some of the bottom fins.  Do you think that this is black ich and what steps should I take now? I am planning to do daily water changes and give dips every 4-5 days. Should I also start administering copper or formalin? I am against using chemicals and would prefer to do things more naturally. How about adding Meth blue to the quarantine? Would that help at all? The temp is about 81-82 and salinity is 1.020-.021. I know he is a difficult fish to care for and I knew this going in so I am not surprised, but just need some more guidance. I appreciate your help.  Thanks, Concerned Caretaker <Hello concerned caretaker. I read your post completely and understand your concern. The Powder Blue is a gorgeous fish and hard to resist buying. Understand that all tangs are more susceptible to ich than other fish. The Powder Blue even being worse. You did the right thing by quarantining for 4 1/2 weeks, very recommended especially with this fish. Obviously you had a lurking disease present in your main tank. Before the tang gets weakened you really need to treat with an ionic copper i.e. copper sulphate. Get a copper test kit since you really need to know if the dose will be effective enough. An effective dose should be around .15 to .20ppm. Try to stay away from the chelated forms of copper as the average test kit cannot measure the true copper level. The dose level of the chelated forms is based strictly on the gallon size of the tank and it is very difficult to determine exactly how much water you have after adding live rock etc, along with the fact that you will never know if you have an effective dose. I would treat the fish making sure the proper dose level is there for one week, which means testing the copper level daily. Good luck with your Powder. James (Salty Dog)> 

Powder Blue Follow Up Date: Sun, 30 Jan 2005 14:06:36 EST Dear Crew, Thank you for your response. I have a couple of follow up questions. If this is "black ich" and if that parasite (worm) is in my main tank, do I need to do something to get rid of it?  <I really don't believe a worm has anything to do with what is going on>  Also, the black spots did not appear on the tang while he was in the main tank when the initial ick (white spots) appeared. The black spots appeared over a week later while in the quarantine. Is it common for the disease to appear over a week later? <It's not uncommon, cysts can easily be transported to QT tanks by way of nets and then go through the other stages in there>  I understand that ick has cycles but the "black spots" came later. The question I am asking is the ick (white spots) and these black spots from the same disease or are they separate? <I'm pretty sure they are separate.>  Are the black spots just a sign of the disease worsening on the tang? I will begin the ionic copper treatment as soon as possible. Thank you for your time and help. Concerned Caretaker  <Eseille, begin the copper treatment monitoring levels daily with a copper test kit. When the disease clears keep the tang in QT for a minimum of 30 days for observation of another outbreak. James (Salty Dog)>

Powder blue tang Dear Bob, I purchased a large beautiful Powder Blue Tang about a month ago and he was  very healthy, no appearances of anything wrong and eating like a pig. I put  him in my 110 reef tank with NNR bed using crushed coral, am planning on  adding live sand later. As of now the tank only has live rock in it with a  3" Lamarck angel that's doing great and a large Yellow Tang that's doing great  that's been in the tank for about 1 1/2 years. All the parameters in the  tank are normal, except I had a slime algae problem but am using Kent  Phosphate Sponge now and the algae is now gone, I've been using it for about a  week now and let me say the stuff really works and fast. The only additive  I use is Seachem's Reef Complete. Just yesterday I noticed the Powder Blue  has bumps all over his sides. Nothing on the outside like worms or ick just  raised bumps. He is doing fine still eating like a pig and no erratic  behavior. Does the tang have an infection or disease, does it sound  stressed or am I worrying over nothing, the fish is beautiful and was kinda  expensive. If it sounds to you like something is wrong do you have any  suggestions and if so any treatments, its weird because the Lamarck and Yellow  are fine looking and nothing wrong with them, should I add something like  Vita Chem or Immuno Vital to add vitamins and what not for the fish, please  let me know as soon as possible if you suspect something is wrong with my  tang so I can catch it early whatever it is, he really is a quite beautiful  specimen, not to many come in as pretty and brightly colored as him. Thanks, Jesse >> Does sound like the Powder Blue (Acanthurus leucosternon) is exhibiting signs of an Microsporidean (a group of Protozoans) infection... but not much to worry about... these sorts of "raised dot" problems are neither treatable, nor infectious to other species... Not an uncommon ailment of larger imported specimens. Bob Fenner

Surgeonfishes: Tangs for  Marine
Diversity, Selection & Care

New eBook on Amazon: Available here
New Print Book on Create Space: Available here

by Robert (Bob) Fenner
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