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FAQs about Purple Tang Behavior 

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Related FAQs: Purple Tangs 1, Purple Tangs 2, Purple Tangs 3, Identification, Compatibility, Selection, Systems, Feeding, Disease, Reproduction, Yellow Tangs, Striped Sailfin Tangs, Zebrasoma Tangs, Zebrasoma Identification, Zebrasoma Behavior, Zebrasoma Compatibility, Zebrasoma Selection, Zebrasoma Systems, Zebrasoma Feeding, Zebrasoma Disease, Zebrasoma Reproduction, Surgeons In General, Tang ID, Selection, Tang Behavior, Compatibility, Systems, Feeding, Disease,

Surgeonfishes: Tangs for  Marine Aquariums
Diversity, Selection & Care

New eBook on Amazon: Available here
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by Robert (Bob) Fenner

Purple tang growth rate discrepancy     1/6/19
Hi Bob, if you don’t answer fish questions on FB feel free to ignore this, I enjoy being your friend so I can see all your excellent dive photos.
<Hey Bri; better to do such here; easier to refer, share, archive>
Basically, I just find this situation interesting, non-urgent, and somewhat unusual (meaning few folks have any insight). I’ve had two purple tangs in a 130 gallon tank for about a year. They typically shoal and coexist peacefully (for the time being). They both eat and are always out and about, but one is clearly dominant and one is clearly submissive, and this has been a constant dynamic.
<Yes; to be expected. See this in the wild and captivity>
What’s interesting is that over the past year or so I’ve had them they’ve gone from roughly the same size to the dominant one being perhaps 3 times larger than the other now.
<This also>
What’s even stranger is they both eat like pigs everyday, the smaller one is not being prevented from eating in anyway. I wonder if it could be due to gender, or chronic low level stress, or maybe some kind of health problem, or a combination of factors, but so far I can’t solve it, and the difference seems to be continuing to increase.
<"Stress" is the best term here. The dominant one affecting the play of hormones through nervous expression here>
So I essence, I was wondering if in your experience this is a thing that happens?
<Oh yes>
I know that purple tangs are sexual dimorphic, in so far as ultimate size, but I didn’t expect it to manifest this quickly or to this extent. I figured I’d see if you felt I needed to intervene in some way (remove one or remove one and treat in some fashion), of if you had other thoughts.
<Mmm; well, both can stay here... but, the smaller one would grow much more, faster if placed in a system where it's the solo Zebrasoma>
Alright man, keep up the awesome diving!
<Welcome! Bob Fenner>

Purple tang has gone crazy (Not a DVD offer...)  -- 02/19/09 Hey guys. <And vimmen!> i am a huge fan of you website and over the last 2 years this is the first time i have had to write into you as there is so much knowledge on your database. Ok so to my question I currently have the following system. 6' long by 2' high and 19" deep. About 20kgs live rock +20 kgs of clay like base rock <Clay like? Interesting... what is this... did you make it... buy it?> And a fairly deep (4 inches) very fine sand bed. It runs standard trickle filtration in that tank running at 2 X 3200 l/h And is lit by a few fluors. 2 X 25w whites and a 4ft actinic (standard with hood although some bulbs are missing) Until about 3 days ago it currently housed the following. A pair of large zebra morays A purple tang A pair of gold head sleeper gobies And a long nose butterfly I had been having trouble with the butterfly as all i could get him to eat was daphnia, bloodworms and Spirulina brine shrimp. As mysis shrimp were too big for him <See WWM re Forcipiger feeding...> The purple tang and the butterfly had had a few minor run ins but had fairly much sorted each other out. No major damage was ever done as the butterfly would just angle his spines towards the tang and she wouldn't go near him. <Good observation, typical beh.> I got back home the other day and i couldn't see either fish. So i turned on the lights, still nothing. But upon closer inspection the butterfly had gone to fishy heaven and the tang was wedged hard into a rock and a hard place. She looked stuck so i moved the rock and she darted around and eventually collapsed on her side. <Mmm, something going sideways here....> Fearing ammonia poisoning from the corpse i removed the dead fish and added some Prime to detoxify the situation and she seamed to perk up. But was still hiding or wedging herself any where she can. It appears if some superficial damage has been done by this. The night before last i did a 30% water change fearing that high nitrate readings were stressing the fish... no sign of improvement <The water change itself could have been trouble> Still 3 days later she only emerges when disturbed, otherwise she just hovers in a cave breathing heavily. What should i do? <Avail yourself of chemical filtrants... Place a few pads of Polyfilter and a couple of units of Chemi-pure or equivalent in your filter/flow path... Note the color change/s in the Polyfilter... something is going on here...> I have available a QT but it has a fairy wrasse in it for the last week. Who seems healthy enough and he is from my girlfriends work so i know he has been in good shape for a while so i don't feel bad about adding him early <I would not> Should i separate the tang into the QT (about 120L)? Why is she still stressed..... <I would leave all in... mix up a good sized batch of change water and store for now... just in case> Please help i don't want to lose my tang. A very worried Mat <Please read here as well Mat: http://wetwebmedia.com/mardisindex.htm Under the orange-red bar... On toxic water conditions. Bob Fenner>

Hello everyone.. I have a short question about my Purple Tang. Beh. ~ 01/12/09  Every once in a while he suddenly develops white splotches "like a total loss of pigment" temporarily for an hour or so in random areas. <Stress... or communicating> He seems very happy and healthy eats very well with no tank-mate problems. Water conditions are excellent aquarium is only 65gallons <Too small, as you seem to realize> temporarily moving to 120 in the near future, just trying to find a spot my wife won't notice it. Anyways is there any concerns? <Mmm, yes... shortening life if nothing else... more susceptible to other diseases...> Thanks in advance love your site and Bob's book it my first and last line of defense. Mike <Glad to help. Bob Fenner>

Purple Tang, beh./markings    8/23/08 Dear Gang. <John> I am an avid reader of your site and recommend it to everyone I know in the hobby. <I as well> My question is this. I have a Purple Tang. It's truly Purple not Bluish purple. It has bright yellow fins. I feel assured It has no striping what so ever. It is healthy. I feed it Nori and Rods with Selcon . I feed it Nori Daily. It is fat and healthy. Is it unusual for a Purple to have no striping? <Mmm, nope. Have seen many as such in the wild and in captivity> Thanks John. P.S. I have been all over the website looking for this answer. <May well be new! Cheers! Bob Fenner>

Daily Q&A. Xanthurum Tang beh., comp.  4/5/07 Hello WWM Crew. <Wilson> I've read your FAQS along with your featured articles and found them always to be informative. Basically -- My problem is that I recently placed my purple tang into my tank (90gallon FO), and by the 3rd day he is having some problems.  When I fresh-dipped him, he pretty much fell to his side and was very unresponsive for 2 minutes (do I have a weaker individual?). <Mmm, maybe... did you aerate this water ahead, during this dip/bath procedure? Could be simple hypoxia...>   Strangely enough, the first 2 days he seemed to be fine, exploring the rock-work and feeding on Nori/mysis/brine/shrimp/bloodworm.   He doesn't feed (all his other tankmates are fine.) or graze on the 3rd day.  When remaining "still" .. he seems to bob very slightly left-right and up-down as well (difficulty to remain exactly upright.)  Now the fish seems to want to just hide, and his breathing rate doesn't seem to be too fast/slow.  There is no detectable fin damage or colour fading, and no signs of HLLE (a popular subject on purple tangs when searching.  The stomach area seems to bulge a bit with pinching in the areas surrounding it (attached picture doesn't show it too well) <Mmm...> The purple tang has shown some sign of slight aggression towards the other tankmates (a Foxface and a smaller clown tang), <Yes... these closely related fishes utilize similar niche/resources... there should be some competition, territorial expression twixt...> but that's only if the other fish approach it.  The Foxface responds by erecting his spines (are they fighting ?) <Yes> What do you recommend me to do ?  Figured I'd solve the problem before it gets any worse (lost one of my favourite fish because I didn't' act fast enough). --Thanks in advance, Wilson <Well... this Zebrasoma was likely traumatized in the collection/holding/shipping and re-handling process... takes a good couple of days getting to us from the Red Sea... and do sometimes take a while to "settle in"... And the presence of the other Acanthuroids is likely having a further negative effect of its development, expression. If you have another suitable space, system, I would move this fish to it... If not, re-arranging the rock work substantially, offering algal food at either end of the tank... may diffuse agonistic behavior here. Bob Fenner>

Psychotic Purple Tang   2/25/07 Hi, <Hello Brian!  Mich here.> I have a new red sea purple tang (Zebrasoma xanthurum)(purchased from liveaquaria.com) in my 75-gallon tank.   <Usually recommend a minimum tank size of 100 gallons for this fish.> Its tank mates are 1 lionfish (approx. 5"), 1 coral beauty (approx 2.5"), 1 copper band butterfly fish (approx. 3"), 1 tomato clown (approx. 2.5"), 1 snowflake eel (approx 9"), and assorted hermits crabs, snails, starfish, and sea cucumbers.  The tank has about 100 pounds of Fiji and Florida live rock and a 30-gallon CPR Aquafuge Pro refugium under the tank with miracle mud and algae in it.  The lighting is a satellite unit with 4 65-watt bulbs (2 actinic and two 10000k).  My chemistry is stable and good (no nitrates, pH around 8.1, no phosphates, no ammonia, no nitrites, temp around 81, and specific gravity about 1.023). <I think a I would raise the specific gravity in your system to 1.025, would benefit the Zebrasoma xanthurum.> The tang eats well (both off the live rock and the food I place in the tank), but its behavior is bizarre.  It will swim up against the same wall of my tank for extended periods of time (as much as ten minutes straight sometimes).  It looks like it is trying to swim through the side of my tank in a crazy obsessive way.  All the other fish swim peacefully around the tank.  Is there something wrong with the tang? <Most likely aggressive behavior in response to the other purple tang he is seeing in your system... i.e. his own reflection in the glass.  Try covering the area where he is displaying the behavior with dark paper or allow to grow over with algae.  Hopefully the behavior will diminish.   Thanks!!! -- Brian <Welcome  -Mich>

Purple Tang & Black Percs  10/26/06    Good evening! <Going on mid-day in this particular space/time orientation>   I keep an SPS reef with 75G fuge/30G prop/100G sump.  The display is a 125G six footer that is "lightly" stocked with:   1XPurple tang   1XSix line   Mated pair of cultured black Percs   Mated pair of cultured Frid Pseudos   and a little orange spot Goby   Aside from that its just Acropora, Montipora, the cleaning service, and a clam.  My question is in regards to the purple tang and the black Percs.  I recently acquired my mated pairs from Inland, both are doing very well.  The Percs ran laps the first three days and have finally settled down in the left hand corner of the tank.  My Purple Tang swims long laps around the tank but every time he comes to the Percs corner he stops and chills for about 20 - 30 seconds right up in their faces.  There is never any outward aggression, you would think he was easing up to a cleaner shrimp, but never the less it bugs me that maybe some passive aggression is going on.  The female perc is the only other fish in the tank that could begin to compete size wise with the tang, she is about 1/2 his size.  The tang just swims over real slow and then very slowly floats among the clowns.  Sometimes it appears that he may be "herding" them away from the corner, but the thing that throws me is how slow everyone is moving while all this is happening. Any advice?   <I urge patience here. The tang is "posturing" for dominance... but there's space for all listed> I have a 75G refugium on this display with a metric ton of tang heaven green and red from IPSF and wouldn't feel the least bit badly about tossing the tang in there if you think this is aggression.  I just do reefs, I don't know much about this fishy business.  The only other thing to consider is that my skunk cleaners have two stations on opposite sides of the tank and the Percs area is very near one of these stations. <Likely the six foot separation will suffice... they'll go to their respective corners in time>    Thanks for your time and attention, I really appreciate it,    Jeff <Welcome. Bob Fenner>

Purple tang I have read through your faq's on purple tangs and I found one that relates to my problem, but I have a few other questions. I recently moved my purple tang from qt to my 55 gallon. His other tankmates were a blue damsel, lemon damsel, yellowtail blue damsel and a gold striped maroon clown. My question is that today I noticed my clown on the bottom of the tank with all of his fins chewed badly. From what I have read, it was probably the tang. My question is that I have the clown in the qt tank now so that his fins can heal but will I ever be able to reintroduce him into the tank or will he just get beat up again? <In this size, shape, kind system, very likely it will never get along with this Tang> Also, would adding an anemone help him when I add him back in? The 55 is soon to be a 135 gallon in a few months, so would I have a better chance of just keeping the clown in qt until the move? Thanks for all of you help,  Deanna <I would wait on all till you have the larger system... then place the tang in a floating colander of size (plastic, for draining pasta normally) and keep it there, separated from the Clown for a week or so... and read re anemones...: http://www.wetwebmedia.com/marine/inverts/index.htm  Much to understand, go wrong...  Bob Fenner>

Purple Tang  <Hi Mike> I was wondering if you have ever come across a Purple Tang that swims very aggressively especially when the lights dim. I just recently added a Foxface to my tank (could that be the issue ). The tang will swim very aggressively from the top of the tank and dive toward a clam then he swims backwards the entire length of the tank. the fish eats well and the water parameters are fine. He has no other symptoms that can be seen only this erratic behavior.<Sounds like the tang is just establishing that he is the head cheese.  James (Salty Dog).>Thanks...Mike

Purple Tang Night Coloring My new Purple Tang adopts a different color at night.... pale, almost whitish with a even lighter splotch in the middle of his stomach, I thought this was normal but my Sailfin seems unaffected, is this normal? <<This is normal. Makes sense too. The nighttime coloration aids in hiding the fish from predators. Bob Fenner>

Is My Purple Tang too Purple? Hello Mr. Fenner, <<Hello, JasonC here - Bob is away diving/taking pictures.>> How are you? Thank you for your past advices, they were extremely helpful. I have questions regarding the color of my purple tang.  <<ok>>  First, let me preface that I have a 90 gallon reef aquarium for the past 3 years. I recently added a 4" yellow tang and 3" purple tang together 3 months ago. Other inhabitants include: 1x -4" male flame wrasse, and 2x -2" female flame wrasse. All the fishes are healthy, and behaving harmoniously, absolutely no sparring or jousting. They are eating extremely well, and are fed 3 times daily with your homemade recipe (finely chopped shrimp, squid, clams, scallops, and oysters'¬Â¦plus soaked with Selcon) that was illustrated in your book. All the food is eaten within one minute. I also feed fresh Caulerpa (from my refugium) for the tangs on a daily basis. My water parameters are near perfect: ammonia = 0ppm, nitrite = 0ppm, nitrate = 0 - 2ppm, temperature = constant @ 78 degree, pH = 8.2 - 8.4, salinity = 1.025ppm, carbon hardness = 10.5 dKH, and calcium = 420-440ppm. <<sounds good.>> The purple tang has a very dark purple hue (almost black) to him/her regardless the time of day. It does not have a vibrant bluish purple coloration and I could barely see the black spots and lines that mark his/her body. All other inhabitants (fish and corals) have brilliant colorations. I am just wondering if it is a nutritional or environmental disorder specific to the purple tang?  <<I highly doubt it.>>  Can the color variation be regional (the Red Sea vs. the Indiana Ocean)? <<more of a possibility, methinks>>  Can it be some type of diet deficiency (although the purple tang has a wide variety foods available, especially with my 30 gallon hybrid ecosystem/liverock refugium)?  <<I would doubt it in this case.>>  Gender differences, if so, how could one differentiate?  <<I don't think you can sex these fish without a knife, but I could be wrong - wouldn't be the first time.>>  Is it a matter of maturity, the color will be more vivid through age? Or is it just a natural variation?  <<both of these are also very distinct possibilities.>>  Should I add liquid vitamins into the tank to enhance the color?  <<you could just put them in the food you've been making, will work as well.>> Thank you for taking the time to read/reply to my questions. Your website provides extremely informative and insightful information to help/educate hobbyists like us. Keep up the great work! <<Bob I'm sure will appreciate your kind words.>> <I am sure we all do. Bob F> Best, Dan <<Cheers, J -- >>

Fwd: [SDMAS] Purple Tang loosing pigmentation Hi All; Does anyone know what would cause a purple Tang to loose pigmentation. <Mainly nutritional deficiency... but water quality, physical damage, disease may play a role> My fish has lost color on only one side and it looks like white blotches. He looks healthy and has been eating. I am concerned because the blotches are getting bigger. The only thing I have done differently has been adding Lugol's one drop a day 5 days a week ( this is what the directions say for a tank my size). Needless to say I have stopped adding Lugol's. Any Ideas?  Maurice B. <I would stop the Lugol's... look into potassium iodide instead. And do utilize a liquid vitamin prep. on sheets of algae in the daily diet. Bob Fenner, WetWebMedia>

Surgeonfishes: Tangs for  Marine Aquariums
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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