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FAQs about Yellow Tang Behavior

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A group of juvenile Yellows hanging out in a branching Pocilloporid coral in Hawai'i.

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>

Yellow Tang issues... color chg., in the AMs...          6/1/15
85 gallon tank, 1.024 salinity, 0.25 phosphate, 10-20 nitrate levels, 78 degrees, 50 #s live rock 1 yellow tang 2 pajama cardinals1 damsel1 black full bar clownfish12 blue leg crabs I purchased a healthy yellow tang two weeks ago, he acclimated very well and quickly. He has eaten every day since I first put him in,
<Eaten what? See WWM re>
he has been very happy and healthy since putting him in. Last night I added my normal dose of purple up,
<Mmm; see WWM re... though am a fan of most all CaribSea products... not this one>
a hour later or so I added a recommended dose of SeaChem stability to aid in good bacteria growth. This morning I woke up to a yellow tang who seem to be swimming fine and all of the fins looked normal. but he was losing color,
<Mmm; when you woke up; as in the tank light/s had just come on? Zebrasoma... all tangs blanch out during dark times>

to a pale whitish color on the front third of his body. The tank is 6 months old and I have not lost any fish since setting it up, I have added and taken out several fish since setting up the tank. Can you wonderful people help me and steer me into the right directions in what is the best step to turn the problem around.
<Not likely a problem here>
I also have been feeding it sustainable aquatics pellet food, the tang seems to love it he gobbles it up.
<Ah, good... do add some purposeful macro-algae... live or prepared as well>
I have fed him this since first putting him in the tank, should I switch to a more veggie type of food? All suggestions advice and input are all appreciated deeply. Thanks for your time.
<Take the stroll (read) through WWM's voluminous accumulations re this species. Bob Fenner>
Re: Yellow Tang issues         6/1/15

Well the lights hadn't kicked on yet, they kick on in the afternoon. Being a executive chef at a resort and in the middle of peak wedding season , I haven't gotten to spend much time in front of my tank. so I woke up at 5 this morning wide awake made some coffee, and thought I would turn my lunar bulbs on and check things out. that when I saw him come outta the rocks looking weird. I usually don't mess with the light cycle, I know it can tend to mess things up. I never see what the tang looks like when the lights kick on, so im not sure if he looks this way every day. I will add some live macro algae and some veggie formula to his diet. when I return home and he still looks pale should I do an emergency water change? thanks again!!!!!
<.... don't worry. READ on WWM instead. BobF>

Yellow Tang; beh.      3/10/15
Thought I'd give this a try as I've been reading posted threads on your site regarding tang behavior. Unfortunately, I haven't come across my question. Anyhow, the tang at the bottom left of the photo is continuously laying down in order to get the other fish to peck on its sides. It appears to enjoy this.
<Mmm; could be appeasement... see your next sentence; might be the fish is seeking "cleaner" help. Heniochus; when small, provide this service in the wild>

We have two tangs in the tank. The other tang counterpart wants nothing to do with this and if it becomes pecked, swims away frantic. I've never seen them do this before and was wondering if it's normal fish behavior.
Literally, it will lay sideways in a submissive
<A clue>
state to allow the others to do this. Thanks for any information you have to pass on. I don't know how big my tank is... maybe 400gallons or so and total population of fish 10. There's ample play room for everyone.
<Thanks for sharing. Bob Fenner>

Yellow tang. Beh./color       4/29/14
Hi there,
I got a yellow tang that is turning orange.
<Neat! Very likely an issue of foods>
I switched from tap water to a ro/di. The ro/di is brand new. Its a air, water and ice typhoon 3. Since I have done this he is turning orange. I have had him for about three years and have no problems. He is eating and
acting fine. From what I am reading sounds like a bacteria, or maybe stress factor. Anything would help. Thanks!
<Not a worry; does happen>
Tank is 150 gallon reef bowfront. Cal- 425, Alk 11, Ph 8.2, Mag 1500.
ammonia, nitrate and nitrite zero. It has been running for three years.
<Just curious as to what you're feeding here... Any Cheetos; orange puffs?
Bob Fenner>
Re: Yellow tang
Hi there, No Cheetos or puffs lol. It almost red orange rash. Just curious if new what it was? I feed Mysis, spectrum pellets, and I soak seaweed with VitaChem. Thanks for you time!
<Perhaps some sort of synergism at play here... an interaction twixt. Thank you for sharing... Oh, and I have a few pix of "Koi" Zebrasoma flavescens... posted on WWM; that have a bit of orange to them. BobF>

Yellow tang behavior     4/23/12
Hi crew!
<Good Morning James>
 I don't know if I should be worried about this fish, or if I'm just a paranoid reefer. No pun intended.
  My tank is a 55 gallon reef tank. The parameters I test for are ammonia 0ppm, nitrite 0ppm, nitrate 5-10ppm, phosphate is undetectable on my dry tab kit. Stock list is an occy clown, royal gramma, yellow watchman goby, yellow tailed blue damsel, coral beauty angel, and a 2 and 1/2 inch yellow tang. I know Im pushing it with the yellow tang but I wanted it so bad. The inverts are various snails, hermits, a few porcelain crabs, a skunk cleaner shrimp, and a mixture of soft corals, and LPS corals.
  Now that we got all that out of the way. My yellow tang was not quarantined before introducing it into my tank. None of my fish were for that matter. I know this was an irresponsible gamble, and I plan on changing this habit in the future.
<I am glad you recognize this, but keep in mind that your tank is now potentially infected with said parasite>
  My cleaner shrimp occasionally picks over the yellow tang and the coral beauty. No fish including the tang show any visible signs of parasites like rapid breathing, discoloration, white or black spots, nothing.
<In the case of Cryptocaryon (marine Ich), the parasite is in the gills and may not present physically for quite some time> They all eat like pigs, poo and swim like normal. The yellow tang however does tend to flash occasionally. Not constantly, but I do see it flash for a few seconds every few days. It doesn't seek out the cleaner shrimp though. Here is where it gets weird. Sometimes I watch the tang offer itself to the damsel like it would offer itself to a cleaner shrimp.
<This could be simply posturing, showing the damsel 'who's the boss'>
 I don't know what to make of this behavior. Its not a huge concern because it eats, plays, grazes, breathes normal, its fins look healthy. This behavior is nothing new either. It has done this off and on for the entire month and a half I've had it.
  Just thought you guys could shed some light on this oddball tang.
  Thank you for taking your time to read this. You guys are great.
<Nothing I can really add based off the information you provided other than to say that as the Tang grows and becomes more territorial, he may become more belligerent towards the other fish.  The tank is really to small for such a fish, especially once you consider rock displacement, etc, but I think you already know this>

Yellow Tang... beh.  8/2/10
Hi! I've only had my yellow tang a couple of months. Yesterday, I noticed above one of his eyes a dark spot. He was still very energetic and eating. This morning, he is hiding and not eating. Also, he is black above both of his eyes...just a small dark circle above each eye. There is no pitting or streaks or anything else. What can I do for him?
<Likely these marks are either "natural" or resultant from capture, poor decompression process... in either case there is naught to do but provide good care. Bob Fenner>
Yellow Tang Problems
One other thing...the discoloration looks like it's underneath the skin.
Like it's in his head, on the top, between his eyes.
<Is indeed. B>

Yellow Tang, night time (de) coloration, beh.   10/22/09
Hey guys, quick question regarding my Tang. My Hawaiian Yellow Tang has bright and brilliant deep yellow coloring throughout the whole entire day.
As soon as it turns about 8 p.m. his body fades to a real pale yellow, almost an off white. What is the cause for this?
<Mmm, natural behavior... likely has some survival value... making individuals less conspicuous to predators... maybe less "delicious appearing" as in "sick"... But not a worry>
I feed him twice a day a mix of omega brine shrimp, Spirulina sheets (on a clip in the tank) and New
Life spectrum along with vitamin C and Selcon supplementing. He is only about right under 3". Ammonia and Nitrite are zero and nitrate is about 30.
<A bit high>
Help me!
<Read here: http://wetwebmedia.com/ytangbehfaqs.htm
About mid-way down... Bob Fenner>

Re: Yellow Tang -- 10/22/09
Is there a possibility that this "fading" defense mechanism is caused by having the aquarium light on most of the day? It's a Lightning Rod 50/50 actinic/daylight.
<Mmm, no, or at least not much... this whiting out one sees in HI every
night w/ Zebrasoma flavescens. A hu'i hou! BobF>

Fish Recuperation, Yellow Tang beh.    10/8/08 Hello my name is Sharon and I need some advice on fish recuperation. I've had my Yellow Tang for 9 months. In August, the Air Conditioning unit at the house broke while I was at work. 120 gallon reef tank experienced increase 82?-83? in temperature during the day time. That night I spent hours adding ice bags to control the increase until the repair guy came and fixed the unit the next day. During that time my Yellow Tang showed signs of heat strokes. At one point we thought he had died. My husband caught him on the net with out a hassle (a very bad sign to us). He suspended the net close to the ice bags and in a couple of seconds the fish started to regain strength and soon it was back to normal. We are very happy to have saved him. <Nice!> It's been over two months and we are very concern about the fish. The Tang swims normal when he thinks he is not being watched. The aggression pattern starts the second he spots one of us. He will start a shaky or firm stop-and-go swim often followed by hitting the sand with his tail. He is not bothering the Clownfish in the anemone above but sometimes we have to leave the room in fear of making him ill with our presence. <Yikes!> The clownfish have no change in behavior and are in good health. At one point I thought it was Lateral Line Disease but I'm not sure this is the case. I've been feeding the Yellow Tang Romaine lettuce daily (his favorite) for 2months. <Mmm, I would replace this with an algae of marine origin... Lettuce has very little of merit in the way of nutrition, and often is a source of unwanted nutrient... Might be a/the source of aberrant behavior here. Please read: http://wetwebmedia.com/ytangfdgfaqs.htm> Every two days he has Mysis dipped in Selcon and the Tang still behaves the same. Is it normal for a fish to behave this way for so long after a traumatic episode? <Mmm, could be an influence... and there are Yellows, other Zebrasoma as individuals that do become "mad dogs"...> Could this be permanent? <Mmm, could be, yes> Is there anything else I can do to help? <Yes... very possibly the addition of another organism will alter this sort of behavior. A small cleaner like a Lysmata shrimp, or Gobiosoma goby... Doing away with the Romaine, substituting Nori, Kombu, or better, some cultured algae that is palatable might well "do it" as well. On the chance that a reflection is at play here, I would darken at least one side panel of the tank (with dark paper)> Thank you bunches! <Do make known your further experiences please. Bob Fenner>

Aggressive Yellow Tang... Tangling Tang  8/24/08 Mich~ <Hi Melissa! Sorry for the delay. I've been out of town for a while.> So it's been awhile. I guess I should do a quick update. <Much appreciated.> Tank is 125 gallons about 5 inches sand, 110 lb LR, skimmer, the usual set up. Things have been fairly uneventful for a bit. <No news is good news.> Inhabitants include snails (Nassarius, Astrea, Mexican Turbos) 2 shrimp (a Cleaner and a Camelback) Chip the chocolate chip starfish (I guess I have had him about 2 years now he's doing great btw thanks to this site) <Mmm... Really? http://www.wetwebmedia.com/chocchipstars.htm ... Not much there!> so fishy friends are a mandarin goby, <Hope you have a fuge.> ocellaris (big Shirley), Maroon clown large, <Mmm, give me a "A" for attitude?> coral beauty (Col. Clink), 2 green chromis. So I bought a yellow tang. He is about 3 inches had been in the 10 gal quarantine for 3 weeks with my cleaner shrimp. <OK... tight quarters> So I tried to put him in the main tank and things went to hell in a hand basket. <Heee!> He has repeatedly attacked the Maroon who took it for a while then started fighting back and he seems to leave her alone now. But he has turned on Big Shirley (I assume is now bob but regardless still call it Shirley) <Heehee! Shirley you jest!> Shirl is about 2.5 inches long and is an ocellaris. She is my favorite fishy and has always been extremely active will swim up and say hello when you get close enough for her to see you. <Very cute!> She will swim right into my hand. <Wow! Neat!> So anyway now Shirl is scared to death under the rocks and panting. I have had to put the Tang back in the QT after I caught him slapping Shirl with his tail and just really working her over. <Oh boy.> So basically I am wondering what my options if any are at this point. I had thought that putting the Tang in last I would hopefully avoid this type of aggression. <Yes, you were wise to do it in this order.> I had to protect Shirl though she has a tattered fin now. <Poor Shirley.> This happened with the Tang being in the main tank only 3 days. <Yikes!> Any suggestions? <Mmm, unfortunately, nothing that doesn't involve removal from your system.> I am to the point I would give the fish away if I had anyone to give it to. Alas, here is eastern KY other fish heads are hard to find. <Did you look here? Not sure where abouts you are located, but maybe you could find some other fish geeks here. http://www.reefcentral.com/forums/forumdisplay.php?s=&forumid=535 http://www.reefcentral.com/forums/forumdisplay.php?s=&forumid=480 http://www.reefcentral.com/forums/forumdisplay.php?s=&forumid=471 > I really would like a Tang in the tank. Do you think there is anything I can do help with this or should I simply find him a new home and try a different fish? <This is the only solution I can think of at this point. I'm sorry.> I should also point out that I did arrange some of the rockwork the day I put him in the main tank. <In this situation I don't think this will be helpful.> I should point out too that I considered a water quality problem for her bahaviour before I witnessed an attack. So I did test everything and stats are as follows : nitrates-0 phosphates-0 nitrites-0 s/g 1.025 so basically all normal. <Yup.> Any ideas you have would be greatly appreciated. <Melissa, I'm sorry I don't have any wonderful tricks to share with you. I do not have a whole lot of experience in this area, but I don't think it is wise to try to keep this specific fish in your established system.> Hope all is well with you. <Yes, thank you and I wish you the best. Mich> Melissa

Bullying yellow tang, Too small of a world 5/1/08 What's up guys? <Hello> I really tried to hold off writing to you as long as I could, but I did not have any luck finding postings with the same problem as me. First off I have a 46 gal bowfront w/Aqua C hang on skimmer and 55lbs of live rock and sand. temp stays around 79, and salinity is around 0.021. Nitrates/nitrites are within reasonable levels. Tank inhabitants include a large 5" maroon clown who has been in there for 3 years A juvenile maroon clown introduced about 6mo's ago. I knew the chance I took adding them at separate times but they get along great. Condylactis anemone, hermit crab and a few snails cruising around. Also the newcomer, a 1.5" yellow tang. <Needs a larger tank, will suffer in here.> The tank size is a bit shy for him, but I plan on upgrading tank size within the next year. <Most likely behavioral/psychological damage will already be done, perhaps permanent stunting as well.> Upon introduction the tang seemed fine. Went through proper acclimation procedures, and the fish looks happy and healthy. The only issue is that every morning I wake up, my larger clown has been having more and more tatters on his fins. I think that the tang is beating him up during the night. <Possible, although tangs are not usually too active at night.> There is a daily Nori strip offered and he eats formula II tabs as well as flakes. I have read about tangs being territorial to newcomers to their tank, but not the other way around. <All fish's personalities differ.> He seems to have "come in" swinging. <Not surprising really, they have the tail blade for a reason.> Do you think this is just a natural acclimation to his environment and tankmates? <Could be.. Or do you think he is just an aggressive fish and needs to be removed? <He will most likely claim the tank as his, and then it will be a battle to the death between the clown and him, either could end up the victor.> This has been going on for around 2 weeks now...... <Watch the tank after dark, see what the tang's behavior is. If it is the tang the behavior will most likely continue if it has been going on this long.> Please help You guys rock! <Thanks> <Chris>

Yellow tang bowel movements 12/07/2007 Hey crew, I have a question about my yellow tang. I have noticed lately that he's almost always dragging his feces around under him. He periodically lets it go but then its usually not long before he takes another poop and drags it behind him for a few hours. His diet consists of Gracilaria parvispora, Chaetomorpha, formula two pellets, flakes, and some meat when he steals some from his tank mates. His favorite food is Chaetomorpha and its easy and cheap to supply so he's been eating a lot of Chaeto lately. If there is Chaeto and Gracilaria in the tank at the same time he will eat all of the Chaeto before touching the Gracilaria. His feces looks similar to Chaeto (stringy clumps) so I stopped feeding Chaeto a few days ago. He also has a not so severe case of HLLE, which is why I got the Gracilaria in the first place. I've had him for 2 months and his HLLE hasn't improved or gotten worse, and for the last few weeks he's been having this problem with his bowel movements. <Mmm, likely needs vitamin supplementation. Please see WWM re HLLE> Do you have any suggestions as to what I might be doing wrong? <Don't think there is actually anything wrong here> He acts perfectly normal and healthy but his bowel movements are rather unattractive and I'm not sure if I should be concerned about this. Thanks in advance for your help. Tony <Zebrasoma do defecate a great deal, depending on the availability of foods... and the algae here are "sticking together" is about it... I would not be concerned, but would address the neuromast destruction... best by improving water quality... Again, see WWM re. Bob Fenner>

Sick Yellow Tang  8/16/07 Hi Guys <Lesley> Hope you are all well. <Yes my friend, thank you> It's been a long time since I have had to email you; thankfully, our tank has been mostly problem free, but I do have a query about our yellow tang. He (or she) has started exhibiting strange behaviour. He swims around in circles (slowly - and not circuits of the tank but rather circles of about 6 or 7 inches in circumference). Occasionally, he'll dart across the tank like a missile and then at other times will sort of angle upwards and "cough" - if that makes sense. His gills sort of puff out! He's not at the surface or anything. I'm not home all day but he doesn't appear to be eating now either. He always grazed the rocks and ate the algae that we put in for him and occasionally ate frozen food, but that seems to have stopped now. This behaviour started yesterday as far as I can tell. <... is very likely responding to its reflection... "Sees" another Yellow Tang... try covering one end of the tank with a piece of paper or such... Could be the season... the inclination of the sun... that has brought this change about> The tank is 100g, with lots of live rock and he only has two tank mates, a damsel and a clown, and one large mushroom. They are all fine. We do have an algae problem and I wondered if perhaps he'd eaten the fish equivalent of "loco" weed. <Heeee!> My husband thinks the fish might have a mental problem! Other than that, he's fat, has a good colour and looks healthy. As far as I can see there are no white, brown, black or any other spots on him and he doesn't have any signs of HLLE. He just looks healthy but acts nuts. Any ideas? I'd hate to think that he's doomed to Davey Jones' locker! <Much more likely is a territorial display... Cut the mirror effect down and this should disappear> Thanks guys! Lesley Saxton <Cheers, Bob Fenner>

Re: Sick Yellow Tang - 08/17/07 Thanks for that reply. Never thought of that! Co-incidentally, we had a chaffinch with a similar problem back in the spring! He kept attacking our conservatory window because he could see his reflection! <Ahh! Yes... not an unusual beh...> Thanks for your help! <Welcome my friend. BobF>

Tang Behaviour Question... too small a world, crowded, nutr. def.   8/2/07 Hi, <Howdy> We have an 8 month old tank , 55 g. with non living Coral and Shells. We have 5 snails, 1 cleaner shrimp, 1 common clown, 5 Blue Chromis, 1 yellow Tang. For the last couple of days the Tang has been swimming around in a calm manner with his dorsal fin up. My question is: Is it normal for the tang to swim with the dorsal fin extended?, <Mmm, yes... but not continuously... something is "over-stressing" this fish... Likely being in too small a volume...> I have never seen him do this, we have had him for 4 months. I feed him Dried Nori from a clip and herbivore tropical fish flake. <Insufficient...> We have tested the water and all levels are within normal range. Please advise. Thank You, Sara Mudge <... Please read: http://wetwebmedia.com/YellowTang.htm and the linked files above. Bob Fenner>

Is this fish normal? Yellow Tang... beh...   3/4/07 Hello , <Hello, Brandon with you today> I  have a question to ask you guys.   I have a yellow tang in a 45 gallon tank. <Your tank is too small, and you will need to upgrade.  Tangs need open water.  I would say one in a 125 gallon tank, to 150 gallons.> It is changing colors like from very  bright yellow to a golden yellow to a brownish white  color.  That  happens when i turn off the lights from the tank.  <I have noticed the same thing on my Zebrasoma flavescens, my assumption is that it is probably a coloration that helps hide it or protect it from predators.> It's very shy and hides behind  live rock. <The hiding and shyness are not normal, and are probably due to the small volume of water that it is in.> Its eyes are sometimes changing colors . It sometimes has like a  black lines going vertical on the eyes. Is that  normal?
<Pleas see above.  Brandon>

How Can You Train Your Yellow Tang to Eat Out of Your Hand?   2/20/07 I saw a picture of someone feeding a yellow tang eating out of someone's hand named Barry Neigut in one of your FAQs. It was so cool.  I have one bright yellow and healthy. I was wondering how could you train it to eat out of your hand like that, without it you know, without it (slashing) your hand!     <I'd start with forceps.  Over time the Tang will associate forceps and eventually hands with food.  If the tang seems aggressive withdraw the food.  Think Pavlov's dog here.>   Thank you.    <You're welcome.  -Mich>

Yellow tang Beh. 1/26/07 <Greeting, Jeff.> i <I> recently purchased a yellow tang, and i <...I> have a lot of live rock in my 55 gallon and all it does is hide in a crack all day.  it <It> will peak out and dash out and eat occasionally, but if it sees anyone walking by it darts to its <it's> hiding spot.  I thought these were supposed to be feeding all day and active.  Is it just the acclimation process, it has been 4 days now. thanks <Thanks> . <The genus Zebrasoma is known for activity and constant grazing. However, all aquarium fishes are also know for their varied levels of comfort when introduced to the captive marine eco-system. If your system has more light than what he/she is used to, then hiding is how to elevate the strain. What you are experiencing is normal, and to be expected. Let the little guy acclimate, and try to put yourself in his/her shoes. http://wetwebmedia.com/acclimat.htm may be a helpful read... -GrahamT.>

Protective Yellow Tang   11/24/06 Hello and thank you for this awesome resource. <Hi there and welcome> I have a 75 gallon tank with a variety of peaceful and mildly aggressive (clown and Hawkfish) fish. Three days ago I added a 6-line wrasse. I'm aware that the Falco Hawkfish I have might go after it, but he has always been passive to new fish. Well he started to chase it yesterday. The yellow tang I have seems to guard the wrasse. <Interesting... these two species are found together... their distributions cross> Whenever the Hawkfish moves, the tang will place himself between the two. He'll even rub against it pushing it into a corner away from the Hawkfish. Reading through the articles here, it would seem that it is marking its territory (Is This Tang A Tough Guy? Article), but it only does it when the Hawkfish is in line-of-sight of the wrasse. I've also noticed my bristle tooth tang doing the same thing. They are starting to take shifts protecting the wrasse.   <Lucky Labrid> Do you think the behavior of the Hawkfish and/or tang will cease? <I give you good odds that this agonistic behavior will end here... in this sized volume, setting> Do you see anything harmful? The Hawkfish won't approach the tang (which makes the tang an excellent guardian). <Things should settle in by and large within a couple of weeks... with just the occasional dart/chase. Bob Fenner> As always, thanks for your advice - Joe

Yellow tang turning white  10/1/06 Hiya I have a new 125 gal. set up for about 8 weeks now. all the numbers are right on. I have added a yellow tang to my tank with my other fish, which are 2 blue damsels 1 tomato clown and 2 small blue damsels with yellow tails. All the small fish seem to be doing good. My questions is about the yellow tang he is turning white at the end of the day. I have increase feeding to 3 times a day and have also purchased green algae sheets and add them. Is this something to be concerned about? What is causing this? If this is a problem what can I do to prevent this? <Tangs along with many other fish can change colors/intensity for many reasons, but often it's due to mood. Stress may be the reason so be sure to double check all your parameters. Make sure you're tank is not seeing large swings in temp and ph over a 24 hour period etc. Have you observed any aggression, hiding, sulking etc etc etc. Keep your water quality up and observe your fish...be prepared to take action if things get worse.> Also need to tell you I had a Naso tang he lasted only 6 days. <Yipes! Are you quarantining these new arrivals? http://wetwebmedia.com/QuarMarFishes.htm> Please help me Thanks Ron <Best of luck. Emerson>

Tang back from the dead!  9/5/06 Not a sci-fi thriller!  9/6/06 Woke up yesterday and found my 3-year-old yellow tang lying motionless on his side at the base of the rocks. <Early in the AM? As in before it was very bright in/outdoors?> He was barely breathing. I left him alone hoping for the best. Two hours later, still no movement and now no breathing. <... still dark?> I reached in the tank, poked his lifeless body out into the open, and pulled him out by the tail. I placed him into a plastic container and prepared for the funeral. <...'begins singing dirge'...> A minute or so later, I went to flip him over to examine his other side for damage or possible cause of death. I noticed his fins stiffening when I touched him. I also noticed his gills had opened up, as if taking a deep breath (container had no water). Then the gills moved. He was actually still alive. <"It's alive!"> He looked clean otherwise, so I placed him back in the tank. I expected him to sink to the bottom, but he actually started swimming slowly. After a few minutes, I put some flake in the tank and he ate. Then I added a piece of Nori on a clip, and within few minutes he was eating that. It's now over 24 hours since his "resurrection" and he is looking and acting perfectly normal. Only thing I notice is a small scuff on one side, otherwise he looks perfect. Did this fish die and come back to life? Anyone experience anything like this before? <Bizarre! Me neither... Yellows (Tangs) do "sleep" on the bottom, motionless during the night... in the wild and captivity. I suspect their lack of motion aids in disguising them to predators. Bob Fenner>

Aloha yellow tang fins turning red/orange  8/30/06 Aloha My yellow tang is turning red/orange color on it's fins he is active and eats fine maybe a little shy it looks like it is on the inside bleeding maybe it's fins are healthy other than the discoloring do you know what this could be and how do I treat it my other tang is fine water quality is A Ok Mahalo for your time Ruth <Please read here: http://www.wetwebmedia.com/ytangdisfaqs.htm and the linked files above... Likely environmental first, bacterial secondarily. Your answers are posted. A hu'i ho! Bob Fenner> Brown? Yellow Tang? - 03/28/2006 I just purchased an exquisite looking Yellow Tang.  All water params. are in line. <Actual measures would be better.> Other fish are doing well. I turned the light on to find that he was a reddish brown color and then slowly turned yellow again. <I believe you were simply observing the natural, night time coloration.> Is this cause for concern? <No.> I read about the diet suggestions for other issues I will do those, as they seem a good suggestion regardless. <Very good. Will avoid the situations in which they were suggested.> This is the 2nd tang. First one died in 4 days. What to do? <Take good care of this one, remain observant. - Josh>

Yellow tang ... what? Beh.  2/18/06 My fianc?set up a 75 gallon tank.  The water was fine, started with established bacteria and everything cycled through.  We added a 3.5 inch yellow tang a few days ago.  Haven't changed anything about the water but the fish may not be eating.  He seems to hide when I put the food in, then after a few minutes of undisturbed water, he comes into view. <Normal behavior.> He doesn't eat right away. After a few minutes, I walk away (call me crazy, but I feel like maybe he just doesn't like eating in public). <You're crazy.> I come back after a few minutes and the food is gone, but for all I know, it sank.  It isn't flakes, its the dry pellets, looks to me like Beta food.  I don't know much about fish, but my fianc?said all I would have to do is feed the fish. <Wish tangs were that easy to keep.  A difficult fish for a newbie to say the least.>  Anyway, the reason I am writing is just now I went to look at him.  It is night, so the light was off.  I turned it on to see if he was ok, <Not a good thing to do at night.> cause he was hiding. <Normal.> I noticed a white line all the way across both sides that matches the white spot near his tail.  It was surrounded by a brownish color.  After a few minutes of the light being on, the brown color went away but the white line stayed.  It just seemed to appear out of nowhere in the last few hours, cause he was ok when I went to bed a few hours ago.  Please tell me what to do and fast, I don't want to loose him. <Your tang is displaying typical nighttime coloration.  Do search the WWM, keyword, "Tangs".  Do read/learn about their requirements, food, water quality, etc.  Your finance should have gotten you something a little more easier to care for, especially someone just starting this hobby.  I'm guessing your finance is just as new at this as you.>   Thanks for your help!!!<You're welcome.  James (Salty Dog)> Becki

Yellow Tang Stressed Out - 02/14/2006 Greetings <Hello. Sorry for your wait.> I recently put a Yellow Tang in my 75 gal. tank which also has 3 Yellow Tail Damsels, 2 clowns, 1 Sleeper Goby, 1 Royal Gramma and several snails and crabs. All my water parameters are checking okay but the Yellow Tang is swimming quickly back and forth at the front of the tank. His coloring seems to be okay other than a white tint to his lower front and horizontally at the center of the body. <Stress markings.> I was wondering if this is just stress or if it is something setting in? Thanks for the information. <Most likely just stress. Make sure it is feeding (on appropriate foods) and keep up on the water quality. The stress should pass as the tang settles in but keep an eye out for bullying. - Josh>

Yellow tang found "cuddling" with domino damsel   1/21/06 We have a 20 gallon tank with 5 pieces of live rock that we positioned to make cavities for the fish to swim under, etc.  We have a choc chip starfish, a blue fish--forget the name not very big, a b&w striped damsel (smallest), a yellow tang and a domino damsel., and then there are some snails too. <Too small a tank for that scenario> Yesterday, we saw the yellow tang and the domino damsel appear to be cuddling and rubbing up gently against each other under the live rock...I have never seen that combo before...of course when I went to get my camera, then returned, my nosey tang had to swim over to see what I was doing outside its domain, so I guess I "ruined" the moment?  LOL!  Is this a normal thing between these two fish to do?  I found it an unlikely combo, or is this something I can expect to see often? <Believe me, they weren't cuddling.  The tang was showing dominance over an area in the tank he wants to call home.  The cuddling was the tang trying to give the damsel a shave with the very sharp scalpels present in their caudal fin.> I couldn't find any info about this particular observation that is why I am writing. <Do search/read the Wet Web on tangs to learn more.> Thank You, <You're welcome.  James (Salty Dog)> Liz Danya Zebrasoma Tang Antics. 12/1/2005 Thank you up-front for your service. <You are welcome, hope I can help out.> I've been a tank owner for 6 months and use your site frequently with questions. I have a 90 gallon vertical salt-water tank with a yellow tang, 6 line wrasse, Niger trigger, <This one is a tank buster and can get quite aggressive. You will need to remove him eventually.> <<Is among the least aggressive of the triggers, can be great big wussies!  MH>> 2 percula, and an anemone (along with the usual rock, etc). My water testing has always run excellent, and I haven't had any major changes in occupants for more than a month. Lately, my yellow tang swims forward rapidly, stops suddenly and flips tail-over-head in a vertical circle. He repeats it frequently, and while it greatly amuses me, it doesn't seem normal. He's eating well, swims normally for food, and I don't see any signs of external spotting or bleeding. Is this OK or should I worry? <Sounds as if he is just exercising. Tangs like swimming room and they will periodically show off their speed. You are at about the minimum tank size for this specimen, how large is it? Does the tank allow for ample swimming room?  <<A 90 tall is not a lot of room for a tang (want to try 4' long?  Just like a 55-60), allows minimal room.  Marina>> Are these flips fast or is he ever in a prolonged side-ways floating state (does he do this trick with ease or is it a struggle)…while it does not sounds like the latter I ask anyway because that could indicate a swim bladder problem. He is still eating and acting normal otherwise so I would not worry to much, Adam J.>  <<This does not fall under the term "normal" behavior in any way whatsoever.  I would begin performing large water changes, and look to current to help solve this problem (assuming the fish really is just trying to stretch its fins).  Watch for color changes, ANY reddening at all is a bad sign, fish must be removed to hospital.  Marina>>

Yellow Tang - strange behavior/sick? 11/4/05 This is my first time sending a message so I hope this works. (and Thank you in advance!) <Welcome> I've been reading all the comments on the website and some address a few of my concerns but no situation was quite the same so I thought I'd give this a shot. <Okay> I have a 90 gallon tank (90 pounds of live rock) and have had a yellow and purple tang for 3+ months. (also have 4 clowns, a lawnmower blenny, a goby and some snails... all seem "normal". All seems to be good but within the last 3 weeks, I've noticed my yellow tangs chest area seems to be a bit sunk in. I feed him flakes, frozen shrimp and algae sheets. <Needs more nutrition> His appetite was good until the last day or so. He is not eaten and seems to be struggling even to swim. He does more floating on his side and seems to be using all his energy. I thought I was going to lose him last night since he was laying on his side at the bottom of the tank all night but this morning he is again trying to swim. I can't stand to watch him suffer. I checked all water levels and even took a sample to the store and everything was good. He doesn't have any spots but his one side does seem to be a little more orange (like more red from the inside) than his other side. <Likely directly related to a lack of nutrition> Is there anything I can do to help this little fellow? Any assistance would be MOST appreciated. Thank you! <Please read here: http://www.wetwebmedia.com/ytangfdgfaqs.htm - Bob Fenner>

Yellow Tang Tango! (Startled Tang!) Your advice has been terrific. Your team does a great service for all of us. <Glad to hear that! We're happy to bring the site to you every day! Scott F. here today!> My Yellow Tang started acting strange when I polished my acrylic tank. As soon as the lights come on he starts a dance.  Twitching, fanning the sand and making himself look big.  From reading the FAQ I believe that this is caused by seeing his reflection in the polished acrylic and acting aggressive towards himself.  He eats great. I understand the problem but not the solution. Any ideas? <Well, there really isn't a great solution here, unfortunately. The fish is in a container with some degree of reflectivity. I think that best advise is to bring up the lights slowly, perhaps in a sequence if you have a timer. This will help to avoid startling the fish with a sudden burst of light. The fish still may want to "dance" with its reflection despite your careful lighting application...Hopefully, in time, the fish will "outgrow" this behavior and spend more time looking for algae instead of doing the "Tang Tango" with his reflection! Regards, Scott F.> Yellow Tang Behavior Dear Sirs, Good day to you or maybe goodnight..... I have a question regarding the behaviour of my yellow tang. A quick run down on my system (running for 1 year) before I pose the problem or question. I have a 280 gallon reef tank, 180Kg + of live rock, yellow tang, 2 x regal or Hippo tangs, blue jawfish, yellow watchman goby, flashback wrasse, fairy wrasse, 2 x clown fish, purple firefish, red hawkfish, water changes 8% every 2-3 weeks.  <Nice setup>  I wont run into any more detail as my whole system is thriving, lovely SPS corals, LPS corals all growing and doing great sorry to go on..... <No Problem but it helps to get your salinity, temperature, ammonia nitrites and nitrates so we have the most accurate picture possible.>  All of the fish are fine except the yellow tang who has for a very long time (6 months at least, had him 1 year) exhibited twitchy behaviour. <Hmm that is a while>  He or She does not spend time grazing on the rocks as I would have expected, he is mostly at the front glass looking stressed 90% of the time. Breathing looks a little fast. He will swim away from the glass about several inches and then dart back towards the glass twitching.  <It might see a reflection of itself and be trying to fight for its territory. Does this only happen when the lights are on?>  All of my other fish are 100% healthy demonstrating normal behaviour. There are no fights and there is no bullying. I've been keeping Marine fish for 17 years but this has really got me confused mainly because of the length of time the Yellow Tang has acted this way. No external marks to the fish and appetite when fed is always there. Could stray voltage be a problem? Or have I got myself a mad fish? Your help would be most appreciated. Kind regards Lee Cheesman. <Well voltage is a possibility, however it being only one fish I would lean toward something else. A good test though for the electricity in the tank is to get a voltmeter and test with the two electrodes to see if it registers anything, and if it does try to figure out what is leaking electricity (check powerheads and heaters). Do you have anything reflective in or near the tank? If the tang sees its reflection anywhere it may be attempting to defend territory as I said above. A good test is to cover the sides of the tank with a non reflective single color cloth or paper etc. use either a blue or a black as they are closest to what the distant ocean looks like. Cover the area that the tang patrols and darts at and then watch from whatever angle you can and see if it calms down. I have personally had several fish that only would calm down if I used a background on the tank back. Hope that helps> <Justin (Jager)> 

Strange acting yellow tang What a great site you have here! Keep up the good work. I am hoping you can help. <Will try> I have a friend with a yellow tang that had reddish areas on it, (LFS said was hematomas?). <Interesting... more likely petecchia, bacterial septicemia would be better descriptive terms here... but these and hematoma are only that... descriptive... they tell nothing/little as to root causes of appearances> Anyway she treated it as directed by LFS, including fresh water dips etc... <Dipping? Not worth the added stress... what were you hoping to accomplish here?> It seemed to be fine. Color was back to normal. When she was transferring it back to the main tank (with only 1 net, not good I now know) it freaked out! We quickly put it back into the quarantine tank, but it was now just laying on its side on the bottom of the tank gasping for breath. It then started turning upside down and couldn't keep itself upright at all. We held it upright for a good 30 minutes (not easy). It seemed to be doing better and within about 6 hours was swimming around close to normal. The next morning she found it on its side on the bottom again and decided to try one more time to "save" it. She again held it upright for about 20 minutes and it seemed to rebound again. Later that day she put it back into her main tank, and just hoped for the best. I personally would have waited... <Me too> ...but, not my fish. Well it now acts like it is has [been] brain damaged. Doesn't act anything like it did before. Won't eat anything except brine shrimp, spends most of its time in a corner staring under a little opening under a boat and when it does swim around it is always rubbing (slamming) its sides into things, which has caused the reddish spots to return, nor is it aggressive toward the other fish any more.  Any clues? Some people have told us that it may be from an air bubble. Is that possible? Thanks in advance. Nadine <... Much important information needed... the size, gear of this system, history of livestock, including this fish... Please have your friend read here quickly: http://www.wetwebmedia.com/YellowTang.htm  AND the Related files (linked, in blue, above). Bob Fenner>
Re: Strange acting yellow tang
Like I explained earlier this isn't my tank, it's a friends but her PC is down and I really hate to see this fish acting (suffering?) the way it is. It's eating the algae food again but has more red blotches and is now swimming more often then not on its side. Ok here's all the info. I have, Tank 29 gal. <This is too small a world for this species> 7 lbs. live rock, 1?" live sand w/ ?" live gravel over it, Skilter 250 protein skimmer, 17w lamp, 78 degrees, 4-5 hermit crabs, 5-6 snails, 1 clown fish, 1 damsel, 1 peppermint shrimp, 1 coral banded shrimp, 1 yellow tang, 1 emerald crab that died today, and one "hairy" crab (came w/ rocks is going to be caught and removed). Fed flake food in A.M. frozen brine in P.M. and green marine algae daily. Tank has been up for approximately 6 months. Tang has been in tank for about 2 months.  As of tonight Salinity 30, SG 1,022, Nitrite <0.3mg/l, ph 8.0, KH 10 (?), ammonia 0.25mg/l (this was 0.mg/l 7days ago). <... where did this ammonia come from?> Co2 concentration 3,0 (don't know if this is important but I made her check it just the same). I don't know much but from what I've read the ammonia is too high and may explain the emerald crab's death. <Yes> I am relaying any and all info. to her. Thanks again.  Nadine <Have your friend read re Yellow Tangs: http://www.wetwebmedia.com/YellowTang.htm  and the linked files: in blue, above. Bob Fenner> 

Itchy fishy or just a matter of self-reflection? Hi guys! I am fairly new to this hobby. I had a 20 gal. for almost a year with 2 perc. I now have a 55 gallon with a magnum 350 pro system with the bio-wheels, a CPR BakPak protein skimmer[ with added airstone] <Good addition> a Hagen underwater filter. I have Coralife 50/50 lighting and I am waiting on my Coralife U.V sterilizer. [these are the best I could do for now, will upgrade as time goes on] Anyway, I have in my tank: 1 perc. clown 1 lawnmower blenny 1 royal gamma 1 flame angel 1 small yellow tang [ I was told I could trade her in for a smaller fish if I thought she was getting too big, of course by then I will be so attached to her I'll probably get a larger tank!] So here's my question, my yellow tang started hitting herself on the rocks, sometimes darting around, I noticed her doing this a couple of days after I got her [about 3 weeks ago] she sometimes twitches and my clown sometimes slam-dances with the glass.... they do not do this constantly They are eating great, I have lots of different kinds of seaweed salad, frozen Cyclop-eeze [ spelling?] frozen Mysis shrimp, zooplankton, frozen emerald entree, frozen pygmy angel formula, frozen brine shrimp plus various pellet, flake foods. <Yummy! I want to be reincarnated as a fish in your tank!> I do not see any spots of any kind on any of my fish but I freaked out went and bought 2 cleaner shrimp, I bought Quick Cure from one LFS and Marex from another I went and bought a 20 gallon beginners tank [has every thing , mechanical, I need]. So I have everything now I still do not see any spots. I am a little scared to use the formalin, malachite green combo.. <You should be... toxic> .. and I cant find much info on the Marex...and I am wondering if I need to treat them if I am not seeing anything on the fish My water quality is good- 0-ammonia 0- nitrites 20-nitrates[ I am working on that] alkalinity- 300 pH 8.2 I was stupid and did not quarantine them first, my only tank at the time had my other perc clown... I regret not qt but its too late now.....what would you suggest I do?? I also have 65#of live rock.[ by the way] please advise as I am a worry wart. Thanks Kim <Likely the very simple explanation is most correct here... your fish/es are mal-affected by their own reflections... Try this: taping a piece of paper over the sides so that they will not "see themselves". Bob Fenner>

Yellow tang and bamboo shark First of I would like to thank you for the info that you give on you web page.  My first ? is that my yellow tang develops  white strip when ever I turn the light off, from your web page I have noticed that this is a common thing, yet is there any way that I can make him feel  safer when the light is off so the strip will not appear. <Totally natural for him to do that. Generally considered sleeping colors.> My  second ? is I just hatched a bamboo shark about two weeks ago. He started  eating white clouds and rosy reds in the light about three days  later.  I wanna know if this is a good sign.  Plus I have noticed that  as I feed him more his breathing has increased and lead to a decrease in  activity. <Digestion but you might check your ph and nitrates both of which sharks are very sensitive to.>  I was wondering if I feed him to much will he become less active, and overall if he eats the food immediate as I put it in the tank is that a sign of good conditions. <Sharks are big eaters and therefore they put out a lot of waste.  So you will need to watch your tank conditions carefully, testing frequently. Good luck, MacL>

Odd yellow tang swimming behaviour hi, I am very very new to this and we have a tank with a yellow tang who has recently started swimming horizontally and spending a lot of time at the top of the tank.  also, his color changes from yellow to white through the day but he is mainly a very pale color.  in himself he seems happy enough, eats well and is pretty settled with all the other fish.  can you shed any light on this? thanks for your time Karen <Something seems awry with this specimen... perhaps there is a low oxygen situation in your system (the fish is stressed... therefore changing color, breathing at the surface...). Do you have the usual test kits? I would check your water chemistry... now. And at the very least execute a good sized water change (25% or so). Do look at the surface of your water. Maybe a film of some sort has collected there (from fatty foods, sprays in the house, cooking oils...). Please list the other fish livestock you have as this provides important clues, as well as the set-up gear, its history. Bob Fenner>
Re: yellow tang swimming behaviour
bob, many thanks for your response. he seems to be doing better after we changed some of the water so I will stop panicking.  I really appreciate your efforts to help though.  many thanks Karen <Glad to hear your fish is going better. Bob Fenner>

Yellow tang eating goby 19 Aug 2004 Hi Guys <Hi Wallace, MacL here with you today.> I have a tank which holds about 600LT of water right now. I had a yellow tang and a purple firefish goby (introduced together). The 5 days or so, the lived together fine, the yellow tang wasn't aggressive to the goby. However, after a few days, the yellow tang started viciously attacking the goby (and finally killed it). <Do you have any idea why? Was it territory? Was it trying to eat it?  What was going on before the attack?> I've now taken the yellow tang out of the tank and hoping to reintroduce it. I'm planning to get a couple more (maybe 4 more) goby's and some other fish before reintroducing the yellow tang again. Is this a good idea ? The only other thing I can think of that might have changed the yellow tang is that I started feeding it live brine shrimp that I bought from the LFS (for 2 consecutive days) just before it started attacking the goby  ... could that have changed the yellow tang to make it more aggressive (maybe since it had a taste of fresh meat? <I don't think it would have changed it. I had a very large Naso that ate tiny gobies, was there a big size difference?> I have a LOT of rock in my tank and its very difficult to catch the fish once it becomes aggressive, so I don't want to go through this again :( <I can relate> or should I just not have the yellow tang in my display tank ? <Here's my philosophy, if I know it did something once, I just don't take the chance that it will do it again. Its not worth the hassle to me. If you can leave it elsewhere I would do so.  Good luck, MacL> Thanks in advanced ..

Zebrasoma flavescens Question Hi, <Hello, Ryan Bowen with you today> I have had my yellow Hawaiian tang for five weeks now and seems to be doing very well with the other fish. During the day when the lights are on, his color looks good and moves around the tank well, except when the lights go off at night he develops a brown spot on both sides of him.  This only happens at night when the lights go off in the tank. He eats very well and looks great during the day when the lights are on. Should I be worried about anything, or is this just his nature? <Common with this fish. They take on a semi-translucent appearance when the lights go out. See here for more: http://www.wetwebmedia.com/YellowTang.htm  See ya, Ryan> 

Watch the Tang do the Tango! >Hello. >>Hello. >I am hoping you can assist with a question concerning the behavior of my Yellow Tang. >>Alright, we'll do our best. >He is one of the more dominate fish in my reef tank. >>Not unusual. >Two days ago he began a behavior that he hasn't exhibited previously. >>Ok. >I expect he is just playing as his appearance is very healthy and he eats all the time. He appears to be fanning the sand substrate with his tail and lower fins. >>I've heard of/seen this before.  It is guessed that, especially with dominant fish, they may be seeing their reflection and either courting themselves or displaying a challenge.  If the fish appears to be making itself larger, this means it's essentially having a standoff with himself. >It doesn't appear to be rubbing his body on the sand but rather just disturbing the sand bed. Sometimes something floats up and he eats it but it doesn't appear he is doing it to feed.  Have you seen this behavior before and do you think it is a problematic indicator? >>Not a problem at all my friend. >Many thanks.

Surgeonfishes: Tangs for  Marine Aquariums
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