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FAQs about the Tang Behavior

Related Articles: The Surgeonfish family, Acanthurus, Ctenochaetus, Naso, Paracanthurus, Zebrasoma , Prionurus, Surgeonfishes of Hawai'i, Surgeonfishes for Reef Systems,  

Related FAQs: Tang Compatibility 1, Tang Behavior, In General, Tang ID, Selection, Systems, Feeding, Disease

Most tang species can be holy terrors if challenged, others are more easygoing, like the Achilles.

Surgeonfishes: Tangs for  Marine Aquariums
Diversity, Selection & Care

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by Robert (Bob) Fenner

And a tang observation; beh.     11/13/17
<Hey Borja!>
Now that some previously unknown abilities of fishes are making it to the media, I have a curious observation.
<Oh, let's see>
In my tank there’s a yellow tang (Zebrasoma flavescens) that has been with me since 2011. I keep the tank
in a location seldom visited by strangers (your typical "man’s cave") and I was amazed at its reaction
when a friend visited.
The fish moved to the immediate area to the front glass and, fins completely extended, it tried to attack or at
least threatened seriously. It made several quick swims along the glass, the “blade” almost touching it.
It never reacts like that when it’s me who moves close to the tank. It sometimes looks like it tries
to get closer (it has learned that I am a food provider of course) and it only gets spooked if I
clean the front glass. It doesn’t threat me if I put my hand into the tank either.
Honestly I didn’t pay attention to the other fishes (I have also a Centropyge bicolor, and angels are supposed
to be more “clever”).
Anyway, have you observed anything similar? It doesn’t matter which clothes I wear, that I wear glasses or not or even being shaved or not.
<Yes to fishes recognizing the "hand that feeds them", and to at times, overtly acting toward strangers in and out of their tanks. Something about the visitor evidently threatened the Yellow Tang... or perhaps it was that there were two of you there.... Bob Fenner>

Tangs in a 180, comp., beh.    6/14/16
First I want to thank you and the crew for all you do for the science. I have been visiting this site for roughly 10 years now and have gained such a wealth of knowledge reading articles and solving many problems and/or avoided many potential problems by doing the proper research before purchasing. So I thank you for your commitment to this site and to
<Ohh, I think you're just about ready to join us!>
With that said I may have potentially made an addition to my tank with out regarding the above words (which Im sure has happened to most in this hobby once or twice).
<Heeee! At this moment>
I recently moved my 55gallon into a 180gallon. I cycled the 180 for 4 weeks using a portion of my 55's substrate and majority of the live rock. I cycled the 55g LR with 75lbs of dry rock and 60lbs of additional reef sand as well as Walt's Fiji refugium mud, obviously placed in the refugium.
After the two weeks of the cycle on the 180 and a water test I added a juvenile Zebrasoma Desjardini that was given to me by a fellow reefer who needed a larger home for him. I was certain after testing the water that  it was safe for him to move in. Those results were: NH3 - 0ppm, SG - 1.025, Temp 78 degrees and stable, PH 8.3, NO3 - 5ppm, NO2 - 0ppm.
He was the first in the tank before any of my livestock from the 55g. A week later (week 3 of cycle) when he was eating and displaying normal behavior I added my male Xanthichthys auromarginatus from the 55g. I re-positioned the LR to create new caves and eliminate any territorial issues, not that these two would have them but just to be safe.
The two co existed fine for an additional week before I did another water test rendering the same results as before and then I added the remaining livestock from my 55g after re positioning the LR once again. The additional LR from the 55g, the remainder of the substrate (that went into the refugium to created a DSB next to Walt's Mud) and the fish:
Paracanthurus hepatus, Zebrasoma flavescens, Premnas biaculeatus (with host BTAs), Amblyeleotris wheeleri, Synchiropus ocellatus, and a Calloplesiops altivelis. (the 55 was overcrowded but everyone played very nice and was only a temp home)
There was also a cleaner shrimp and a few peppermints who didn't make the transition unfortunately. Not sure if Bob, the Xanthichthys  auromarginatus, killed them or if something else happened but they are no longer with us
<The Trigger might have been involved>
The issues I seek your opinion on has to do with my tangs. After the first week the hippo ended up with pop eye which has cleared up on its own, but now he seems to hide a lot more then he used to.
<Just give it time here>
I had hoped that the larger volume of water would create space for these guys to really swim and explore the tank freely. The Maroon hosts and stays out of the group and the Marine beta is only out at night, but the hippo, who I adore seems to
be stressed by something. The two Zebrasoma's do a little sword play but no one seems to be showing signs of injury. I do have only about 120lbs of rock. I like my tanks to have pillars and columns of rock and not just a wall so they have a playground to swim in. Could it be that I don't have enough hiding spots?
<Doubtful... just time going by...>
In fact the hippo hides out in the same cave as the trigger and seems to do so most of the time now. Could the addition of another circle bodied fish Zebrasoma Desjardini, be causing all this drama?
<Possible; but one last time... this should pass>
My LFS told me to purchase another Zebrasoma to even out the pack, but they also want my money, so Im reaching out to you as to what to do.
<I would not add another here>
I would like to add as my final tang to the party a Acanthurus achilles, but at the price point and sensitivity of this species I am going to wait till the tank conditions are fully stable and cycled and this Zebrasoma stress issue out of the mix.
<Good; this is what I'd do as well>
If you could please advise as to your thoughts to my Zebrasomas and if I need to find a new home for the Zebrasoma
Desjardini I will do so.
<I'd leave this one here. No to another Sailfin tang individual>
Tank Info just in case I missed something above:
180gallon (6'x2'x2')
NH3 - 0ppm
SG - 1.025
Temp 78
PH 8.3
NO3 - 5ppm
NO2 - 0ppm
55gallon refugium: LR, DSB, and Fiji Mud (separated by baffles) as well as two soft balls of Chaeto
120lbs LR
LED Lights on a schedule
Misc SPS and LPS Corals
2 RBTAs that share the same hangout
handfuls of Blue Leg and Reg Leg Hermits
Fighting Conch
Nassarius Snails
Fromia indica (who ended up eating the cleaner when he perished)
Emerald Crab
Sally Lightfoot
Thanks your loyal reef reader,
Spencer Hall
<Thank you for sharing and your kind words. Bob Fenner>
Re: Tangs in a 180   6/14/16

Bob, thanks for such a swift reply. One last question re the future Acanthurus achilles. Do you see my current livestock an issue with adding this delicate fish.
<Not really... "just" the usual issues of easy-parasite gain you hint at>
I consider myself an experienced hobbyist and feel I could handle the care for this animal, but do you feel there
are incompatibilities with my current tank mates?
<None especially; no. There are individuals of the species you list/have that at times prove irascible (like our current Cattle Dog toward other canines), but I give you good odds here. BobF>
Re: Tangs in a 180   6/14/16

Excellent, thanks so much Bob!
<Ah, welcome. B>

Marine fish and stunted growth    3/16/14
Hi gang, I am a marine aquarist of about 25 years, and I wanted some expert opinion on something that's been on my mind.
I understand popular belief is to buy fish that even when they grow will not get too big for the tank.
<Assuredly not so... there are "negative feedback loops" (oh to have these in/for large bureaucracies!) like pheromonal behavior effects that can/will reduce rates of growth... but there are indeed bad consequences of such stunting>
However, I have had a number of yellow and hippo tangs over the years in tanks of 125 gallons or less. Even after 5 years, not one has ever gotten larger than 5". In smaller tanks the same held true but on an even smaller scale. On the other hand my wrasses and triggers seem to grow regardless requiring tank upgrades :).
 So, at least with tangs, IME they seem to grow according to the size of tank they are in. Can you comment on this observation. Thank you.
<Likely the slow down/stop of growth here is mostly a matter of both nutritional (input) and competition from other livestock... This article may interest you: http://www.wetwebmedia.com/FWSubWebIndex/GrwLmtChems.htm
Bob Fenner>

Fish Question     8/30/11
Dear Bob (and Crew),
I've had a nearly 4" Acanthurus bahianus for almost three years. Around four months ago I converted my 72-gallon bow-front tank from crushed coral to a fine aragonite. Around the same time I also introduced a dwarf angel who has since died. Somewhere along the way, the tang started pooping white sand.
<Tangs do ingest substrate... thought to aid in digestion, perhaps trituration, akin to the crops of some birds>
Nothing slimy looking, nothing "clingy or stringy," but also no other kind of poop that I've noticed. He just poops white sand.
<Not to worry>
I'm not sure whether this is related to a parasite that might have come from the angel, or if the fish just happens to eat this new kind of substrate while grazing. Appetite seems fine, and he doesn't seem to be losing weight. I'm tempted to throw in a Praziquantel-based food in case there's a parasite, but there are also some shrimps and a hermit and I don't know what it would do to them.
<I would hold off on treatment>
None of the other fish (two Firefish gobies, a false perc, a royal gramma) are pooping anything unusual.
Should I be concerned?
Thanks in advance,
Rick Koch
<Welcome. Bob Fenner>

Fish Behavior/Tangs/Behavior 3/18/10
Hello Crew,
<Hello Ray>
I do not want to ask you a question. I actually would like to share an interesting story about the behavior of my fishy friend, that others might be interested in reading. I think it just shows how smart fish really are and how they bond with the person that cares for them.
<We welcome such stories.>
Last night I was observing my fish when I noticed my Sailfin Tang displaying really unusual behavior. First of all his (I don't know if the fish is male or female, but I'm going to use masculine pronouns) color contrast was increased drastically. His black stripes were darker than ever and his white stripes were pure white. He began to twitch as if he was being annoyed by something that was touching him. I looked at him close up to try and find what could be wrong, but I couldn't see anything. Then, he began to scratch one side up against the live rock and walls of the tank. That is when I located what was affecting him. There was a human hair about five inches long that was caught around his left tail spike. I reached my hand into the water and tried to grab the hair and rid him of the irritation it was causing him. As I slowly moved my hand closer to him he slowly swam backwards away from me. I can tell he was looking at me as if unsure if I was trying to help him or hurt him. I moved on to plan 'B'. I kept my hand near the top of the water at the opposite end of the tank. Then, he slowly and cautiously swam towards my motionless hand and turned sideways with his affected side facing upwards. He got within about an inch of my fingers and I was able to pinch the hair with minimal movement and take it off of him.
Some of my fish let me pet them when they come up near the surface of the water, but never has a fish shown so much trust in me. I think people really underestimate the intelligence of these animals.
<Thank you for sharing your experience with us. All I can say is this fish must trust you an awful lot. Were you wearing a Cleaner Wrasse costume while you were doing this by chance :)?
James (Salty Dog)>
-Ray Fuller

Slow Tang Growth (Feeding) -- 02/12/10
I was wondering if Tangs grow slow or is it because water quality?
<<Water quality/other environmental conditions can/do have a marked effect on a fish's health/growth>>
I feed them Mysis, brine, krill (cubes), squid with Selcon, Vita-Chem, Vitamin C, Zoecon, and Nori/seaweed 3 times a week... I had my purple tang for 2 1/2 years now.
<<A nice variety, but'¦ Aside from any other factors that may be present, the fact that you only feed three times a week is key. Tangs are not exceedingly fast growers in my experience, but limiting their nutritional uptake is certainly going to slow growth. I recommend you feed sparingly 'three times a day' versus three times a week. If this proves to be too much re water quality then the system is likely undersized/overstocked'¦ address this as needed, but not at the expense of your fishes' nutritional well being. Cheers'¦ EricR>> 

Tang Behavior: Tang Intelligence 4/11/2009
Hi crew,
<Hi Mani>
My message today is more a comment than a query.
I have only recently started focusing more on tangs from the Pacific and have a turbulent SPS infested 475 litre set up with exclusively tangs (and one very fat Splendid Mandarin), all thriving and fit.
My comment is on the intelligence shown by many of these species. Of particular interest is the Sailfin. Not sure of the gender but lets call him "he".
<Fair enough>
A most observant individual, he spots me from 30 feet away entering the fish room and usually comes right up to the front for a bit of an eyeball when I am examining something close up.
<Very common with Tangs.>
His favourite is Nori (seaweed) and when he sees me take a sheet out of its pack, he heads straight for where the veggie clip is mounted and acts all excited. He also plays some complex games, having devised an obstacle course internally among the live rock. He teases his best mate the Yellow Tang into pursuing him, then dips into a crack in the LR, disappears and turns up a couple of feet away emerging literally on his side on the bottom under a large head of LR, *behind *the unsuspecting Yellow, who remains flabbergasted despite having this done to him several times a day.
<Also common, I have a Sailfin that plays "tag" with his buddy, an Ocellaris Clownfish.>
Very interesting character with a range of visible moods shown by the intensity of his coloration, varying from deep chocolate to pale gold with blue. I was looking for something on your site relating to observation of intelligent behaviour, could you possibly direct me to any such notes?
<There isn't much out there I'm afraid. A quick Google search did not turn
up much either, here are a few links
http://www.aquahobby.com/articles/e_intelligence.php >
I am also very keen to keep octopuses, maybe even a "blue ring" one day
<Octopuses are fine in specialized systems, Blue Ringed Octopuses are an EXTREMELY bad idea. Bites are usually fatal.>
....unfortunately NZ bio-security just won't allow even simple *Pterois Volitans* into the country!
Meanwhile I am currently setting up a NZ-native biotope, complete with a tidal pool section. There is some stunning native temperate/sub-tropical marine life here, and if you are interested I can send some pics once its up and running.
<Please do!>
Thanks for listening!
<My Pleasure, Mike>

Tang spots     2/16/08 Hi Crew, <David> I previously posted ...but after over 2 weeks the "issue" keeps returning. <I see> I have a 3"-4" Scopas Tang that I've had for about 2 months. Starting about 3 weeks ago he displayed flashing, periodic scratching, heavy breathing, then several faint soft-edged spots just in front of his tail( in order of symptom appearance). First it was only on one side, but within a couple of hours it was on both sides. The spots progressed into a larger "patch" made up of the spots. The patch/spots only appear above his tail.( see pic) <I see this> I quarantined all of my fish and treated with QuickCure ( Formalin & Malachite Green). Within minutes of the first dose the Tang looked much better - normal color and patch seemed less apparent, less labored breathing. 3 days of QuickCure ... filter in. Next day the patch returned ( approx same location)! Complete tank cleaning and 3 more days of treatment. Again, Tang looked much better - one might even be tempted to say he looked "cured". Again, insert carbon filter ...24 hours ...white spot, same location ...with labored breathing! Other 3 fish removed to a second QTank ( no signs of disease). So, I've started the 3rd round of treatments with QuickCure. Today is day 2. <I would cease this exposure... too toxic, not likely to effect a cure> My question is ...is this Ich or Velvet or some other nefarious ( I threw that in for drama) parasite? See attached picture. The patch has been more distinct, but that's what he looks like today. Ich, Velvet, Other ...? <Other> Suggestions on treatment alternatives? <Time going by, careful observation> A beer to the one who successfully gets this Tang "cured";) <Oh!> A sincere thanks for your time and thoughts. David <This tang is damaging itself by "flicking" the tang on this, its favorite side... likely in response to its own reflection (internally, inside the tank). Try placing a piece of paper on the side it seems to stay most on "jousting" and be patient. Bob Fenner>

Potty Trained Tang? 01/30/2008 Hello Crew, Chris here. <<Hello Chris, Andrew today>> Long time no email! I consider that a good thing because it means that I'm not having any problems or I'm finding all my answers on the site. My one question today is on tang behavior. I've had my Kole Tang for about five months now. He seems to have the habit of using the exact same spot to go to the bathroom. He goes in between a piece of live rock and the corner of the tank. To the point that there is a pile of "stuff" building up in the corner. I looked through the tang behavior FAQs but didn't see anything on the subject. Doesn't seem to be causing any problems, I always vacuum some out on water changes. Just wanted to get your opinion on the behavior. <<Very common indeed. However this points out one issue which does need addressing and that is flow. If the tang is leaving packages behind and they are just staying there where left, it means that you have a real lack of flow in this area. Detritus should not be allowed to settle in the tank, rather held in the water column to be removed>> <<Thanks for the question, have a great day. A Nixon>>

Re: Life after ich 10/17/07 Hi Bob, <Stan> How are you? Good, I hope. Per your recommendation I have let my tank go fallow the last two months. All my fishes made it through the two month hospital stay with fly colors. In fact, they came out more lively, more colorful and with more girth than when they went in. <Great> Three days ago I acclimated and returned all fishes to the main tank. Everyone took to their new surroundings well, eating and poking around actively. After observing for 3 days there are two things I see that concerns me a bit and I would like your advice on them. First, the 4 inch A. japonicus is harassing the 6 inch A. leucosternon because brown wants blue's cubbyhole. <Common interaction twixt Tangs of the same genus> Brown would circle around while blue jealously guards it's hideout, occasionally darting out to chase brown away. When blue decides to go out for a while brown would invade his hole. Blue would come back and run him out. When both happen to be in the open brown would follow blue around. Blue would get annoyed, turns around and nip at him but brown will not be intimidated so the dogging continues. This scenario plays out maybe 60% of the time. the rest of the time they leave each other alone. I am waiting for some kind of pecking order to kick in but at what point should I pull brown out of there? <... if too much...> Seems to me brown is the troublemaker even though he is the smaller one. Right now there is no nipping or tail swatting, just some chasing and minor jousting. Second question: The purple tang is pacing in front of the glass at one end of the tank. It's always the same spot. He goes up and down for half an hour at a time. <Very likely reacting to an internal reflection... cover one end of the tank with dark paper or such> I tried to cover that panel with black cloth but he still does it although not as much. I also tried leaving the lights off, closing the drapes all to no avail. Will this stress him out? <Not too likely> Will he suffer for it? He does this 40% of the time. He eats well and gets along well with others. Thank you in advance and keep up the good work. Stan Young <I would consider some smaller "dither fish" here... perhaps some hardy Anthiines or Apogonids if you have room... Bob Fenner>

Fighting/Loving Tangs? 2/5/07 Hi there. <Hi> We currently have a problem with two tangs. We have had our tank running now for around 1 and half years and never had any trouble with any of the fish.  Currently have1 blue tang,1 brown tang,1 yellow tang, 2 clowns, 1 wrasse, 2 cardinals,1 cleaner wrasse, 1 yellow Chromis, 2 shrimps, 1 majestic angel, 1 star fish, 1 urchin.  They have all played together well for a long time and we have not introduced any further fish in as we obviously have enough.  The problem is with our beautiful brown tang (our very first fish) and our yellow tang.  We have noticed that they seem to be rubbing their tails together a lot. <Not good.> I thought they might be loving each other a little too much... <Not love, aggression.>  However feel that they might be doing quite the opposite. <Yep>  I read in one of your answers that the little white glad like things are actually spikes? <A switchblade of sorts, hence the name surgeonfish.>  I have noticed that the yellow tang has nips in his fins (not too bad but noticeable) and also has turned a white colour where the rubbing occurs. <Getting beat up.>  One would chase the other - then the other would chase it.  I would of thought that if one was getting picked on more, then they would go hide and not chase the other when its not chasing..... confusing. <Trapped and cornered, no other option.>  ?? Please can you give some advice on what to do? <Separate the fish.> Why are they fighting now? <That's what happens when they mature.  You don't list your tank size, but I'm guessing that is adding to the problems.>  They just cant keep away from each other - and have a lot of room to roam around in.  <Not enough evidently.>  Thanks heaps  :o)   Jodi <Chris>

Catching a regal tang  - 10/22/06 Hi there, < Greetings, Emerson with you today. > Our Regal tang has outgrown our 90 gal tank and has become aggressive to other fish, corals, etc. It won't go near the fish trap that we've been successful with in the past and my husband suggested catching it with a hook (barbless). Any ideas on catching this monster? < Try draining the tank until there's just enough room for the fish to remain upright and catch with a container. If you don't have enough containers to drain this much you can get some light diffusing grid, trim to fit the tank and use as a divider to isolate the tang to one side making capture easier. > Thanks, < You're welcome and good luck! > Lisa

Tang diarrhea??   9/16/06 Hi Crew, I've tried looking in the forums and the FAQ's but can't find anything to help me. I have a 250 gallon reef with 30 gallon Miracle Mud sump, a few 100 pounds of live rock, numerous corals and critters all lit with 2 x 250W metal halides on for 7 hours a day.  Fish wise I have: 1 x 8" Acanthurus grammoptilus 1 x 3" Centropyge loricula 4 x 3" Pseudanthias squamipinnis 4 x 2" Chromis viridis 1 x 4" Blue cheek goby 1 x 4" Lawnmower Blenny 2 x 2" Australian black perculas I feed the tank 3 times a day with a mixture of Mysis, Krill and Cyclop-eeze. I feed the tang 1 sheet of dried Nori daily. Today when I fed the tang, he came up to the lettuce clip with the Nori on it and ate well. However, shortly after eating his first helping, i noticed he was already passing feces. The feces looked just like the Nori and almost as if he has diarrhea. Is it possible he could have a stomach or bowel upset? His behaviour is normal otherwise. His weight seem normal also. He does like to take krill and Mysis that I put in for the other fishes, would this affect him at all? Water parameters are as follows: Amm - 0ppm Nitrate - 0ppm Nitrite - 0ppm Phos - 1ppm (I know a lil high!) Temp - 23 - 24 C SG 1.022 Any ideas would be gratefully received, Thanks and keep up the good work! Martin Sutcliffe (UK) <<Martin:  As long as your tang is eating and its belly is full, don't worry about it's bowel movements.  Mine, have interesting movements.  They are fat and happy.  Best of luck, Roy>>

Gassy Tang   8/31/06 Hi crew!   First let me thank you guys for the response I got last time it was a big help for a worried hobbyist.  I just had a question about my tang,  I looked in the archives and any reference that I found to gas was on gas bubble disease which doesn't seem to me to match up with the difficulty my little guy is having.  When he defecates often it is accompanied by gas.  Is this normal? <Mmm, no... but have seen>   He eats a lot of dried seaweed, I also feed him formula one but he prefers the seaweed.  I am working on getting some live rock I know that will be beneficial to his general health.  Could it be that the water has to high of a saturation level? <Not likely... I think you're right to point to the dried seaweed diet here> In this tank, which is a 110, I have two Skilters which are each rated for supplementary filtration of a hundred gallon, two powerheads one for seventy five gallons one for forty five, a UV filter for up to one hundred and twenty five gallons, and a wet-dry for one hundred and twenty five. There doesn't appear to be too many bubbles in the tank but I am relatively new to the keeping of marine systems.  Also the tang seems as though he feels good he swims around looking happy, appetite is voracious, and he relieves himself quite often.  I love him so much, I don't want anything to happen to him.  Any advice will be much appreciated.  Thanks for everything, I don't know what I would do without your site. <I would try the live rock, maybe culturing some live macro-algae... but otherwise not worry here. Bob Fenner>

Kole Tang Run in with Tunze….once an accident, twice a mistake, but more get a clue?   7/25/06 Hi there: <Hello> My Kole Tang has been a super tough guy since I got him in December or so. Always big and fat and eating. But on day 2 for reasons unknown I had to free him from the overflow intake.  Hmmm... Then in January, he twice was stuck to the intake of a Tunze 6060 rotating on Sea-Swirls.<Poor guy> That was odd indeed.  Second time he was on it for a while, seriously tattooed on one side. <Hmmm I probably would have done something creative to keep the fish from the intake and overflow the first time there was a problem. Perhaps the pumps are to strong or the fish weak for some unknown reason.> Recovered from that though too. <Lucky fish>I target fed to make sure he ate well and frequently, at least 3x a day. Starting maybe in March, I'd say every couple weeks I'd arrive home to see that the scales were missing in a splotch on one side, almost always on his left side.  In fact, I think always….that is the side he was stuck on that last time on the Tunze. <I wish you were kidding but I have a feeling you're not. Seriously you need to do something to keep that poor fish off the intake of that pump. 4 months every 2 weeks…. so the poor fish has been injured at least 8 times in the last 4 months, not including his original 3 injuries. How many times does it have to happen before you do something about it?> Anyway, I'd always target feed and he'd always eat and it would always clear up within a couple of days. <Very resilient. It's great that you are taking such good care of him after he is injured but some prevention would go much further. One of these days the poor fish will not be so lucky.> I'm thinking, tough guy. <Perhaps initially but every time he gets hurt he is probably getting weaker, with a good chance of some permanent damage to that left side.> Now I am not so sure. Tonight he is deep within the rockwork, not breathing hard, but hiding.  I can see that the scales are missing between his eyes right on his head, and a bit on the side of his mouth. Hard to tell much else as it's dark in there, even when the lights are blasting away!  Not a chance of getting a picture. Most worrisome is he didn't come out when he saw me or when I fed the tank and that is an absolute first. <Indeed, not a good sign.> That has me concerned in the morning he'll be gone. <As you should be, there is a good chance he could be. I would try turning the lights off and doing a water change.> When I say the scales are missing is I see white flesh. I figured wounds somehow against the rocks or maybe he picked a bad fight, though with whom given my stock I haven't a clue.  He should be the boss. <Hard to say given you have not listed the tankmates. Less dominant fish will often pick on injured or weakened fish.> Anyway, white flesh is apparent now on his head similar to in the past when always on his body. <Perhaps this was his last run in with the power head intake. If not and he survives you need to do something with that Tunze intake> Any ideas what this could be or what I could do??? <Sounds to me like he had yet another run in with the Tunze. If you can gently get him out of the tank, you could try putting him in another tank to recover….. a hospital tank where he is safe from the Tunze and other fish. Set it up similarly to a quarantine tank with hiding places. Keep the lights off and water quality good. If he survives PLEASE do the poor fish a favor and do something with that pump intake. Build a mesh basket around it or place a sponge over it. We do this all the time in seahorse tanks. It's really not a big deal. It may not be esthetically pleasing and the sponge will need to be removed frequently to be cleaned, but at least the fish will be protected from further trauma. This may sound harsh, but needs to be said… once an accident, twice a mistake but really 3 and on up times is irresponsible to say the least. You really should have done something a long time ago. It is your responsibility to protect the creatures in your care from  harm as best you can.  Leslie.>
Re: Kole Tang Run in with Tunze….once an accident, twice a mistake, but more get a clue? (continued) 7/25/06
No, you have totally misunderstood.  I don't know how you misread that but sorry for my part. <I apologize for the misunderstanding> Anyway, the Tunzes are out.  I now have modified MaxiJet 1200s on the swirls, he's never had a problem with them. <That's good to hear> These wounds are not the wounds he had when stuck in the pump, and began to appear months after those incidents, which have not recurred. This is not a pump issue. Something else is going on. I have a pic now at www.ostrows.us/sickkoletang.jpg  I'm wondering if there is some parasite or bacterial disease that could do this? <It's possible but hard to say for sure. Those are good-sized white patches/wounds. It is really hard to tell from the photo if they are actually wounds with broken skin or white patches. In my experience white patches of bacterial and parasitic etiology are not usually that size when first noticed. There is usually some indication something is going on earlier, before the patches get to that size.> Tankmates: 2 green chromis, 1 royal Gramma, 1 percula, 1 hepatus, 1 scribbled rabbit, 1 mandarin goby, 1 Flamehawk. He's the biggest except for the rabbitfish. <I am going to guess that perhaps he injured himself on the rock or was injured by the venomous spiny rays of the rabbitfish. If he seems to be holding his own in your display tank and none of the other fish are bothering him I would leave him where he is and keep a close eye. In addition I would recommend a water change, maintaining stable and pristine water quality as well as the addition of a vitamin like Vita Chem to a healthy varied diet. I would also add some Bets Glucan to his food. You can get this at most health food stores. Beta-glucan is a potent immunostimulant that provides important health benefits for fishes. Research indicates that it helps prevent infections and helps wounds heal more quickly; it is safe to use in conjunction with other treatments and has been proven to increase the effectiveness of antibiotics; is known to alleviate the effects of stress; and to help fish recover from exposure to toxins in the water (Bartelme, 2001) . For more information on Beta Glucan for aquarium fish, please see the following article: http://www.advancedaquarist.com/issues/sept2003/feature.htm If he does not appear to be doing well in your display tank and the other fish are harassing him. I would remove him to a hospital tank and follow the above directions. If the wounds appear to be getting worse you may want to consider the addition of medication. I hope this helps, Leslie>
Re: Kole Tang Run in with Tunze….once an accident, twice a mistake, but more get a clue? (continued) 7/29/06
Guess who is all healed ... again. <Wow, that's amazing and great to hear.> I'm half expecting that within 10-14 days he'll have whatever "it" is even worse, and that is going to be hard indeed to witness. I sure hope I'm wrong, <Me too.> but this has been on a steady schedule and progressive. <Hopefully this is the end of it. As previously recommended do keep up with the water quality please do try the previous suggestions for Beta Glucan and Vita Chem. Best of luck to you and Mr. Kole, Leslie>

Insomniac Tang   7/26/06 Hi guys, your thoughts on this would be appreciated. I have a blue Atlantic tang, which I collected about three years ago at about 1.5". He is housed in a 180 FOWLR and has since grown to about 6", in  excellent health. No unusual tankmates. During the day, he is a normal swimmer and grazer and not abnormally skittish, a typical tang. At night, though, he  drives me crazy. The tank is lit with 4 moonlight LEDs. <Likely the cause of trouble here> Mr. Tang, unlike his tankmates, does not rest. Instead, he swims rapidly back and forth. Over - and over- and over- for hours. I have yet to see him rest, except during daylight, and then not much. He seems none the worse for this, which he has been doing for years. I have kept more than  a few tangs, but have never seen this behavior; I have come to the conclusion that there is nothing amiss I can fix - but I would welcome any comments.  Thanks, Steve. <I would turn down if not off these night-time lights... This fish "sleeps" during nighttime hours... not getting rest due to the lack of periodicity... Bob Fenner>

This Tang Won't Shut His Mouth! & Sexual Dimorphism  12/7/05 Good morning. <Hi there! Scott F. with you today.> I have a question about my Yellow Tang. I've had him for about 3 months now. Never remember seeing him with his mouth closed. Is that a sign of some kind of illness or it meant to be this way? <Well, I cannot recall seeing a Tang with his mouth perpetually agape, but if the fish is eating, that's a good sign.> He looks good and eats everything I throw in like: shrimp flakes, blood worms, Formula2 and his favorite - dried algae. Now, should I be worried about that open mouth of his? <I'd be more concerned if he was not eating. Sounds like the open mouth could be a result of an injury or developmental anomaly. If he's eating, just keep up the TLC and take comfort in the success you're having with a fish that may not have made it in the wild!> BTW, is there a way to tell if it's a boy or a girl?  Love this fish. Don't wont to see him/her in trouble. Thank you, Tatyana <Well, Tatyana, I'm not aware of any reliable, simple external sexual differentiation in these fish. Do a bit of research on the 'net to see if you can locate anything. Sorry I couldn't help you on this one, but enjoy your fish! Good luck. Regards, Scott F.> 

Acanthurus olivaceus pooping behavior, BGA control 10/30/05 Steve here. <Bob here, HI and Hi> Hope this email finds you well. <Yes, thanks> A couple of questions: I have a Juvenile Orange shoulder Tang around 3.5" long and have had him a few months now. He acclimated very well and getting along with his mates. He eats well, grazing off of 250 lbs. of live rock, Nori on a clip, and variations of Omega Flake food, Ocean Nutrition Pellet w/ garlic, frozen cube, etc. <We're out diving with this species most days> My question is that when he "poops" a steam of what looks like sand comes out. <Good observation> It almost looks like my very fine live aragonite sand that is in the deep sand bed. He picks and feeds off of the sand bed along with grazing off of the live rock. I can see his ribs, but I think I read on your site that it was not uncommon amongst Tangs.   <Correct... they do ingest bits of substrate... sort of helps... like some birds' crops... with tritiation/chewing...> Second question: I wrote recently about a fight with Red Cyano that has been forming on the sand bed. I physically remove it (siphon) and have performed weekly 10% water changes, watching that I don't feed more than the fish can eat and not adding any other nutrients to the tank. The tank is 215 gallons, 50 gallon wet/dry, refugium with Caulerpa, 250# of Tonga live rock and the water parameters are fine, ammonia 0, nitrite 0, nitrates 10 ppm, salinity 1.024, water temp 80.5 - 81.5 F. I have ready on your site that treating chemically is not advised, so I have been doing all of the things this site recommends like clock work for two weeks and if anything it has gotten a little worse. <Mmm, you might want to consider modifying that wet-dry, switching to another genera/species of macroalgae... perhaps improving your skimmer/skimming...> I put a sock of Phosphate granules, increased aeration, cut down on nutrients, and performing water changes weekly (at least 10%). My Ph has remained stable at 8.3. Please let me know if I am missing anything, or should I be looking at something like Chemi Clean (by Boyd)? I don't want to add anything that will kill my live rock, or good bacteria and I suspect that anything that will kill Cyano bacteria may do so. Thanks for your words of wisdom. Steven <Don't know re wisdom... but do take a read (again?) through the WWM files on Cyano... not hard to control once you know how. Bob Fenner> 

Mimic Tang Swimming Sideways 7/26/05 Hi Crew,     I recently noticed my tang behaving very strange. He will just dart off swimming sideways fast. I inspected him and have not seen anything visible on him and he eats as usual with no other problems. I was wondering if you could explain why? <Mmm, some tang species, particularly the mimics and Paracanthurus do "swim sideways" quite a bit... If you had only had this fish a week or two I might suspect swim bladder damage... from lack of decompression or poor needling for same... Bob Fenner>

Tang Color Changes Hi! I have a couple questions <Ask away! Scott F. with you tonight.> I have a 44 gal salt water tank with a yellow tang and a few other fish, everyone seems to be doing fine, except I notice once in a while the tang will lose his bright yellow color and become almost a white yellow then go back to normal. Is he ok or does he need more food:? <Well, there are a few possibilities here. The first is that you may be witnessing the fish's nocturnal coloration, which is significantly more "washed Out", and reveals the presence of a white line running the length of the body. The fish will generally color up once the lights have been on for a while, so that is what you are witnessing if this coloration coincides with lighting changes. If this happens throughout the day, you could be seeing a fright reaction, or a response to some sort of stress (whether caused by harassing tankmates, poor environmental conditions, disease, or even a tank that is too small). Check out all of these possibilities. Yes, overall lack of color could be a result of malnutrition, so be sure that your Tang has access to plenty of algae, or consider purchasing/cultivating some macroalgae, such as Gracilaria parvispora (you can get it from etailers like Indo Pacific Sea Farms), which is relished by most herbivorous Tangs, and provides many nutritional benefits to the them.> Also what kind of fish go good with tangs and damsels and a Valentini Puffer. I recently added another fish and the tang chased him around for a couple hours but now they are buddies. <A common behavior with a dominant fish! Good luck with your Tang! Regards, Scott F.>

Indian Ocean Mimic Tang Hi, <Hello there> I recently bought an Indian ocean mimic tang and it is in my QT with 2 common clowns  and a six line wrasse. It has 0.4 mg/l of copper in the form Seachem Cupramine. I plan to keep them there for at least 30 days. <Copper is hard on Tangs> The other three side of the tank is covered with a blue backing and is lighted by a small lamp. The problem is that the tang is swimming frantically along the front of the QT. When I go near and stick a finger at it (in front of the glass) he will swim back and hide behind a plastic pot. Within a second he is back out swimming frantically. <Likely in reaction to its own reflection...> The clowns seem kind of stress by his behaviour and appears to be hosting the flower pot. They used to be swimming around everywhere before  the tang was introduced. Is there anyway to explain this behaviour? Is it normal? <This animal is probably seeing its own likeness... you might try decreasing the light inside the QT tank, or covering the outside/last panel... Bob Fenner> Thanks. Chee Thong

White- faced tang attacks Hi everyone, I have a quick question regarding my white- faced tang, Acanthurus japonicus. I have had my 72 gal tank setup for well over a year now. I have about 90 lbs. of Tonga branch rock, a remora pro skimmer, a HOB refugium, and all water param.s test fine. Up until about a week ago, the only inhabitant of the tank was a bird wrasse. She/he was doing fine. I initially bought the wrasse as a she, blackbird, and it seems that she is attempting to turn into a male specimen. Now she is about half the color of a female with blue and green fins. <Neat> Somedays she is more blue than others. She has been like this for about 3 or 4 months. Last week I received two additional fish to add to my tank, a Lemonpeel Angel and a Powder Brown Tang Acanthurus japonicus. Everything was going fine when I initially put the fish in. I noticed that the tang had a slight scratch on his side a few days later, which I assumed was from accidentally running into a rock while exploring my tank. When I woke up this morning I found the tang following my Bird Wrasse around, which I thought was cute. I was wrong. I quickly noticed that the tang would get along side the wrasse and attack him/her with his spurs. After a few times of doing this the wrasse would nip back, which accounts for the scratches on the tang. The tang is acting very aggressive to my wrasse, chasing him/her all around. I have not read about this sort of behavior, considering that the wrasse has been in the tank for over a year and is twice the size of the tang. The tang is about 3-4 inches and the wrasse is about 7-8 inches. Do you have any suggestions as to what is going on with these two inhabitants? <Testing each other out> The Lemonpeel angel is doing fine, neither fish is bothering him. <Too small, fast to dive into the rock work> Do you have any solutions to this problem? I would like to curb this aggression as soon as possible. Thank you for all the help your site has given me. <The easiest (wait till you try and catch it...) approach is to separate the tang... in a floating plastic colander (pasta strainer) for a few to several days in the tank... this will likely "calm it down". Adding other fishes will also serve to distribute/dissipate aggression. Bob Fenner>

Powder Blue Tang is "chattering" Hello, <Hi there> We have a healthy Powder Blue Tang which exhibits an odd characteristic of seemingly "chattering" his mouth from time to time. It is always looking out of the front of the tank and very often at us. It seems to do this for no apparent reason, but also it seems when something is wrong in the tank, like when our Yellow Tang was getting harassed (to death recently by a 5 Stripe Wrasse we traded in today). Is this chattering behavior common for Powder Blue's or do you think it is its way of telling us something is wrong with the water? Everything seems to be healthy and only our Nitrates are on the high side. Kim and Paul <Good observations and descriptions. I actually believe your Tang IS trying to "say" something... It is seeing its own reflection in your aquarium surface and "communicating" with it... Should be fine, and this behavior will likely cease in a few months. Bob Fenner>
Re: Powder Blue Tang is "chattering"
Bob, <Paul> Thanks ! It seems to "chatter" regardless of the lighting outside the tank though, so I'm not sure about the reflection theory. <Hard to imagine perhaps... but having been inside very large aquariums... there is reflection from the inside!> It makes the most sense since it does seem healthy. Thanks for the quick response and your knowledge. I've gained insight in the past from reading other postings you've had.  Paul <Ahh, glad to render assistance. 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

Tang aggression to reflection Hi there! <Hi Wes, MacL here with ya.> I have had a yellow tang for about 4 months now in a 75g tank, doing very well.  Sometimes it looks as though she is showing signs of aggression to her reflection in the glass.  Is this something to be concerned with? <Typical tang behavior Wes. Nothing to worry about whatsoever.> Thanks for your help! Wes.

Tang Territorialism Jim, I have two dark blue damsels and one white and blue fin damsel and one small black and white fish and a mimic tang. The culprit is probably my mimic tang and alas the cardinal did not make it. Also I have a sebae clownfish that has a small dark discoloration on his rear fin. He seems to be happy, he eats and swims around like he is happy. However the tang and he are kind of interacting a bit. Is the tang going to try to run all new fish off. >>>Tangs are territorial, to differing degrees depending on the species. I have no direct experience with mimic tangs, but I do know 55 gallons is on the small side for them. 75 gallons is the minimum tank size for the smallest species long term. Jim<<<

Tang aggression - 11/17/04 I am new the world of salt water aquariums. <Welcome!>  In setting up my aquarium, I was advised that I would need to have 1 or 3+ tangs in a tank. <Not unheard of at all. In fact I have more than once witnessed HUGE!!! congregations in the wild.>  Nothing was said about them needing to be different species; however, now through lots of research I have learned that the tangs were all from the same species. <Correct> They all seemed to be fine but 1 died anyway.  I then was left with a Yellow Tang and a Scopas Tang. <It sounds like there is some confusion regarding genus and species.  I would recommend putting several of the same species (i.e. three yellow tangs) in together, not different species of the same genus (i.e. Zebrasoma flavescens and Z. desjardinii) - different species of the same genus often have aggression issues.   It can also be a real problem when you try to add new fish to an established collection.  You did the right thing in rearranging the rocks, but you may continue to have aggression.  It might be good to move (i.e.. trade) both the yellow tang and the Sailfin tang and put in three new tangs - same species at the same time.  Before, you do that though, the number of tangs added would be determined by the size of the set-up, so we need get some more information on the tank set-up, size, live rock, etc.>  The Yellow started becoming very aggressive towards the other. <Exactly. Again not unheard of either> I was then informed that I needed to add another tang of the same species by 2 different sources.  I have recently purchased a Zebrasoma desjardinii and given different ways to introduce him into the tank.  The new fish decided that he liked the rock that the yellow tang liked which as you can guess became a problem.  Therefore, we rearranged the rocks and turned off the lights. <A very good idea but usually doesn't have long term success> That seems to have made some difference, but I can still see some aggression by the yellow tang.  The yellow tang does now leave the scopas tang alone.  Tonight I noticed that the desjardinii has a small cut beside one of his fins.  Am I going to lose my new fish from this cut? <Not likely. Keep water quality high. Change the water over at 10-20 percent each week. Watch for an infection or further damage. If the latter is the case, then remove the fish for recovery in a separate tank. I don't recommend treating the tank, though. No need to add unnecessary stress to the filter or the other inhabitants.>  Is there any way to treat it or will it heal on its own? <Should heal on its own with good water quality>  Do I need to remove the yellow tang? <See above suggestions>  They are not fighting over the same territory since I rearranged the rocks. <May work but not likely over the long haul. Again, see above suggestions> Your insight is much needed and appreciated. <Thank you for coming to WetWebMedia. ~Paul> Sheryl Chambley

Tang aggression toward clownfish 8/16/04 I have a 3 1/2 inch purple tang and I added a 4 inch Yellowstripe Maroon Clownfish last night. The Tang is tearing up my Clown. The clown is just sitting there and taking it to the point that there are tears in the Clown's fins. Will this fighting stop? The only refuge the clown finds is in the Rose Bubble Anemone that I have but when it closed up, the tank attacks.....is there any suggestions that you might have to get this to stop?  thanks, JB <JB, Sorry for the slow reply!  Fist of all, I am amazed that the clown is taking it.  Generally maroons are very aggressive and don't take any abuse from anyone.  Unfortunately tangs are quite aggressive as well.  If this has not stopped by now, one or the other will have to go as soon as possible.  You don't mention much about tank size or hiding places.  75 gallons is a reasonable minimum for either of these fish at their current size, but may not be spacious enough for them to cohabitate.  The problem will be worse if there are not a lot of nooks and crannies to claim as territory.  Best Regards.  AdamC.>
Tang aggression toward Clownfish 8/16/04
There is a lot of hiding places for them both. I took the tank out and put him in m QT tank for a day and a half and let the clown settle in. The tang has stopped most of the hard attacks. He darts at him but that is about as far as it seems to go now. He is not tail swiping him anymore. The clown is defending his space a little better now and things have really calmed down compared to the other day. The tang is actually letting the clown swim around the tank some now, thank God. Thanks for the help. JB <Good to hear!<

Sinking the Hook and Line Good afternoon, <Hi, MikeD here> I am hoping to stumble across a silver bullet here. I would like to remove a blue tang that has gotten too big and a Domino damsel that has worn out his welcome from my 72 gallon reef.<I've heard this before!!> I have tried to feed from a net waiting for the fish to swim in, but they are too smart. Do you have any tips that I can use to remove these fish without disrupting my corals and rock?<The method I'VE had the best luck with is to utilize a one gal. glass jar that you lay on its side with the mouth facing out into the tank and some of their favorite food placed inside on the bottom.  Once they swim in and begin to eat, approaching from the mouth end, place the lid on, cover it with your hand or even your net and voila! They are out. When they see your and coming they will usually panic and try to escape through the clear sides.> I am thinking of trying at 2am when they are in the fog of sleep to snatch them out of the tank. It is not worth it to me to damage my soft corals with the net to get these fish out.<That I understand They also make some commercial fish traps for this purpose too.> Thanks, Eddie

Naso Tang Blowing In The Current? I have a question for the fish experts at wetwebmedia.  My Naso tang has been doing great for over 5 months in my 180 tank.  Recently he has begun to swim with a waggle, for lack of a better term and he will turn sideways and roll.   Rather than being quick and alert like he always has been, he is being blown around a little more by the current.  Should I be concerned or is there any actions / diagnosis you would recommend? <Good observation on your part. Although it may be nothing to worry about, the fact that this normally very strong fish is  displaying some signs of weakness, getting blown around in the current-is certainly a cause for some concern. If you are not seeing any other obvious external signs of illness, such as white spots, excessive mucus, rapid breathing, etc., then no further actions may be required except for continued good husbandry. On the other hands, if additional symptoms of disease manifest themselves, please feel free to let us know.> He is eating well - mostly seaweed selects green algae on a clip with some Selcon soaked in.  He now eats some of the Mysis and flake that I feed the rest of the tank (yellow tang, ocellaris clown, lawnmower blenny).  Could this be a nutritional issue?   <It is certainly possible. I'd try offering some fresh macroalgae, such as Gracilaria, which is en excellent supplement for tangs. You can get some at my favorite e-tailer, Indo Pacific Sea Farms. An excellent food for herbivorous tangs!> Until recently, he had no interest in anything I would feed except the algae on a clip.  The other fish are fine and the yellow tang is acting as usual.  The two tangs have always been a little scrappy but nothing to the point of injury. The only other abnormal thing that I can think of is that the Naso will sometimes have a circular lump in the stomach area after eating. <I would not be overly concerned about that at this point, unless the fish shows other difficulties...> Any insight you may have is appreciated. <At this stage of the game, I'd employ continued observation, frequent small water changes, regular feeding, and testing of water to assure that all is well. In short- keep doing what you're doing! Good luck! Regards, Scott F.>

Excuse me, sir, but is your Tang High? >I have a question for the fish experts at wetwebmedia.   >>Uh oh, thanks be to Bob for putting me on the spot with this one!  <gulp> >My Naso tang has been doing great for over 5 months in my 180 tank.   >>Ah, I love it, suitably sized system for this fish. >Recently he has begun to swim with a waggle, for lack of a better term and he will turn sideways and roll.  Rather than being quick and alert like he always has been, he is being blown around a little more by the current.   >>This is odd, and something I've only seen commonly in freshwater fishes.  Would you describe this as "drunken" behavior? >Should I be concerned or is there any actions/diagnosis you would recommend? >>I would definitely be concerned, but of the ailments I'm familiar with, none would include what follows, nor a good prognosis.  Honestly, I would expect to see this in a poisoned fish (cyanide exposure - in my opinion likely NOT a factor here for how long you've had the fish, or parasitism, of the brain? Not impossible, but I wouldn't know how to address it).  How are the other fish doing? >He is eating well - mostly seaweed selects green algae on a clip with some Selcon soaked in.   >>You are fantastic!  I couldn't offer better. >He now eats some of the Mysis and flake that I feed the rest of the tank (yellow tang, ocellaris clown, lawnmower blenny).  Could this be a nutritional issue?   >>I doubt this very, very much.  You *could* add one or two good quality frozen (mixed) foods to this menu, but the Selcon does much for all the fish. >Until recently, he had no interest in anything I would feed except the algae on a clip.   >>So, if I understand you, he is now interested in that which held none for him previously?  (Tell me that question made sense) >The other fish are fine and the yellow tang is acting as usual.   >>Jeez, that rules that out.  I wonder if there are any nudibranchs or similar that he could have ingested which may cause this.. kind of like a piscine loco weed? >The two tangs have always been a little scrappy but nothing to the point of injury.  The only other abnormal thing that I can think of is that the Naso will sometimes have a circular lump in the stomach area after eating.   >>If he's thin despite eating a great deal, then this IS a problem and could be either a symptom or partially a cause of the odd swimming behavior.  If he is not well-fleshed and rounded out, especially behind the skull, if you can see the spine (under the lateral line) at all, ribs, etc., then this fish is definitely too thin and you must begin free-feeding him and offering LOTS more proteinaceous foods to help fatten him up. >Any insight you may have is appreciated. >>At this point, that's all I can offer, I'm sorry.  If you have more questions, then I'll ask for photos that I can share with some other crewmembers to get their input on this as well.  If you do so, please include the text of this message as well for background.  Marina

Scared Tang (4/12/04)  Hi, I have a yellow Sailfin tang, but when I came from home from work today he was no where to be seen. I checked where I could within the tank (we have a lot of live rock) and in the canopy, in case he jumped out. Usually, he is the first to know when it is feeding time, so we fed the fish. Still he was no where to be seen. About an hour later, we noticed him scavenging for food; when we approached he would hide. This is very uncharacteristic; he is not usually shy or afraid when we approach the tank. Finally, he came out enough for us to see him and he was a very dingy brown color. I have attached a picture from several  weeks ago and one I managed to get today. Is this a sign of disease? If so, should he be removed? Is this a sign of other troubles in the tank? <The Tang appears to be exhibiting its fright colors.>  I have recently made a few changes: (1) The addition of my first SPS corals. (2) Up until a week ago, the temp would fluctuate between 77.x - 81.x degrees each day, but I recently added a fan to the sump and it now maintains a steady 78 degrees. (3) I started adding Kalkwasser to the top-off to provide calcium. <Nothing here sounds bad, unless there is some problem with your Kalkwasser dosing. I'd suggest a check of the ammonia, etc. More likely, something has this Tang very frightened. Is there another fish that may have turned on it?> Any help would be appreciated. Thanks! Dave <hope this helps. Steve Allen>

Is This Tang A Tough Guy? Hi guys, <Scott F. your guy today!> Wonderful site.  I've learned a tremendous amount just reading through all the FAQs.  I have all faith that you will be able to answer this question for me. <I'll do my best!> I have a Yellow Tang that I've had for about four months in a FO tank and all has been great with him.  He looks happy and healthy...I swear I can almost hear him happily humming as he swims around picking at the algae growing on the rocks. <Ok- put down the coral glue... : )> Beautiful little guy.  The strangeness started about a month ago when I introduced a Shrimp Goby in to the mix (I also have a Porcupine Puffer, Saddle Puffer, Niger Trigger, Flame Hawk and a Yellow Tail Damsel. <Interesting bunch> All the fish have been getting along really well...no fighting or anything at all.  But I did notice on two occasions, the last being this evening, that the Tang would go up to the Goby (just the Goby...no other fish or any other object in the tank) and rub his tail up against the goby's side. It almost looks like the Tang is "marking" the Goby as his territory. It's not the kind of rubbing or scratching that would occur when a fish is infected/infested with a disease or parasites (I've had the displeasure of witnessing that in the past...not a fun thing to see).  It sincerely looks like he's just "marking".  Do Tangs do that...mark their territory? <Well, not so much "mark" their territory, but in captive situations, in particular, they will let someone know if they are in "their" territory! Sounds a lot like the behavior that you are witnessing> And if so, why would he be marking the Goby?  He'll use the white gland-like things  (I'm not exactly sure what you would call them) that are located on both sides of his tail. <Called the acanthus, this is mainly a defensive weapon, but it can be used in an offensive matter! Those little spines are sharp! trust me!> This will go on for a couple of minutes then the Tang would just swim away and go about his business.  But there's never any fighting between them.  And like I said, he only does this to the Goby and none of the other fish. <Sounds like he's just giving the goby a little "attitude". Nothing to be concerned about unless things get ugly> Do you have any idea what may be going on here?  Is it anything I should be concerned about?  Any input  you may have would be much appreciated. Thanks a bunch, Carlos <As above, Carlos- I'd just chalk it up as one of those interesting behaviors that you can only witness in an aquarium! What a cool hobby, huh? Enjoy! Regards, Scott F.>

Surgeonfishes: Tangs for  Marine Aquariums
Diversity, Selection & Care

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