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FAQs about the Damselfish Behavior 

Related Articles: Damselfishes, Clownfishes, Jumbo Damselfishes

Related FAQs: Damsels 1Damsel Identification, Damsel Systems, Damsel Selection, Damsel Compatibility, Damsel Feeding, Damsel DiseaseDamsel Reproduction

Can't bite me, I'm armor-plated! Ostracion meleagris male pic by SabrinaF. Hawai'i pic.

Fishy Cooperation: Scientists Discover Coordinated Hunting Between Groupers, Giant Moray Eels    1/4/12
> Hello Marco, Bob,
> Thought this might interest.
> http://www.sciencedaily.com/releases/2006/12/061206095317.htm 
> Cheers, Neale<Have observed this association in the wild myself. B>
And now saltwater Piranha! I.e. some damselfishes!    1/4/12

Really? Sounds extraordinary.
Am watching a new BBC documentary called "Great Barrier Reef: Nature's Miracle". Some amazing footage. There's the Epaulette Shark, which apparently is adapted to the reef top. During low tide and when exposed to air, the shark can walk about on the coral from one pool to another, and even shuts down parts of it brain to conserve oxygen. Apparently this is its ecological niche, feeding at low tide when other fish and crustaceans can't move about or escape from pools of water.
There was also a White Damselfish, apparently the fish responsible for more attacks on divers than anything else on the reef. Not fatal ones of course!
If this show appears on BBC America, do watch.
http://www.bbc.co.uk/programmes/b0198pww
Cheers, Neale
<Ounce/gram for ounce/gram, the toughest, most territorial animals I've ever encountered>

Dirty Damsel, beh., comp.   7/26/11
Good Day,
<Hi>
Recently my husband and I purchased two Damsel's. We purchased living substrate, live rock and a 25 ounce bottle of BioSpira that we added after letting the tank cycle. We introduced the two Damsel's together, unfortunately, after the fourth day it seems one has become the aggressor.
He allows the other to eat and have some freedom from his corner of the tank but only on a tight leash.
<Typical of most species of damsels, they can be very aggressive.>
The other is now very angry as indicated by his black color. He has turned the other from a beautiful purple.
<Stress markings.>
Should we allow this behavior or take the aggressive Damsel back to the store?
<They may need to be separated.>
Also, Mr. Aggressive turns all the way on each side and rubs himself repeatedly on the live rock. He only does this after he has worked on his nest. Subsequently, is there anyway to stop this nesting behavior?
<No, not really, damsels generally will dig if there is substrate.>
We are concerned that he will end up bringing a living rock down on him while we are not at home and trapping himself.
<Is a real possibility, you may need to shore up the rockwork with PVC tubing or plastic ties.>
Best Regards,
Christy Carter
<See here for more http://www.wetwebmedia.com/damsels.htm .>
<Chris>
Re Dirty Damsel, 7/27/11

Thank you Chris.
<Welcome>
What do you make of the "scratching" against the live rock. Could this be a sign of a parasite?
<Could be, but could be nothing too. I would just watch for the time being, see if any other symptoms appear.>
Again Best Regards,
Christy Carter
<Chris>

Couple very interesting fish science reports 12/4/10
Hi Bob,
> The first is about male Bettas being observed to watch fights between other males, and with the information they gather, choosing not to fight against males they determine to be good fighters. This type of behaviour has hitherto only been reported from advanced mammals and birds, but reveals that fish may have far more complex social behaviour than scientists thought -- something I doubt surprises you or I very much!
> http://indianapublicmedia.org/amomentofscience/siamese-fighting-fish-keeping-score/
> The second is about water temperature and fish behaviour, damselfish becoming bolder and more aggressive as temperature rises. Obvious relevance here for marine aquarists as well as, perhaps, conservationists given global sea temperature rises.
> http://indianapublicmedia.org/amomentofscience/fish-personalities-why-water-temperature-matters/
> Cheers, Neale
Thank you for this Neale. BobF

Damsel fish "body shaking"? 11/08/10
Hello WWM,
<Dylan>
So I have just recently had to restock my tank and I started out with a few damsels. The tank is cycled and has been up and running for several months, before putting the animals in the tank I had my LFS double check that all the parameters on my tank were what I thought they were (all good). So, I get 3 chromis and one yellow tail damsel. (I think one of the chromis and the yellow tail got into a bit of a fight as it looks like he's missing part of a fin.)
<Happens>
I noticed that all the fish were hanging out in the lower left, back side of the tank, an area that is pretty sheltered, so I just figured they were getting used to a new environment. Later that night I noticed that yellow tail acting "funny". It looks as though he is having a perpetual seizure, just shaking his head back and forth with lots of body twitching, this was followed this morning by two of the chromis doing a similar type thing. I can't find any postings anywhere on this behavior.
<Mmm, likely "natural"... Pomacentrids and many other fish groups do this behavior... for signaling (territoriality), reproduction et al.>
Obviously I am worried about some sort of contagious thing here? I'm a little worried about Ick as my last batch of fish was pretty much wiped out by a Tomato Clown that I'm pretty sure had Ick, the tank was treated and a few of the fish survived, for a while. Although I do not see any of the typical signs of Ick, like the "sugar/salt" specks on fish or "flashing" behavior. This is a 20 gal system
<Ahh, very small, particularly for Chromis spp. Damsels>
with some live rock in it. Any suggestion are greatly appreciated, I just don't want to loose anymore fish. Thanks, Dylan
<Or lose them likely. Please read here: http://wetwebmedia.com/chromsysfaqs.htm and the linked files above. Bob Fenner>

Re: Scooter Blenny stomping over mushroom corals... now Damsel beh....  7/26/2009
Apparently after I send you that message, I found my male damsel hiding in a rock. I then saw that his lip was detached as well.
<Possibly from aggression if there are multiple damsels in your tank. They can be a rather aggressive species! I've had damsels bite me in the wild!
They can be very territorial.>
I'm amazed at my female damsel as it made a 100% full recovery but my male damsel seemed to have
suffered brain damage and slowly wasted away after I reintroduced both of them back into the main tank. The male stayed at the top of the tank in a vertical position and would occasionally dart forward and back several times and then resume his vertical position. Over a period of a week I saw his yellow tail slowly fracture and become clear. Two days ago I looked into the tank and I saw him at the bottom.
<Sorry for your loss.>
It's unfortunate, but at least the female made a full recovery and slowly gaining the lost territory back from a
nearby female.
<I would keep a close eye on the interactions between these damsels.>
Thanks for your help!
<Welcome
Mich>

Re: Neon Velvet Damsel (Paraglyphidodon oxyodon)  1/18/09 Hi guys, a follow up and a question. These two damsels seem to get along fine, no nipped fins or anything so far. <Good> As of this week however the little one is losing it's white stripe. <Ch, ch ch changes...> The neon color seem just a bit darker, but may be my imagination due to the white disappearing. The large one is just fine and has great coloration and minimal color loss since it was little. <Natural... what is that adverb?> Both absolutely healthy and active, not a fin or scale out of whack, great appetites, swim and play in the rockwork, come out to visit when I get near. <Ok> Is this color change due to the natural change, and the larger one is just slower to change? <Likely> Is the little one changing... to be less conspicuous to the larger one? Thanks Much, Dave <Also likely. Keep watching, learning... B>

Odd Damselfish? Beh.    12/15/08 Hello there! Ok, I have a question regarding some Blue Neon Damselfish, <Mmm, what species is this?> as my LCF called them, for they are acting strangely. I just recently bought 4 new damsels where they were placed in my 45 gallon tank, where two other damsels of the same species already lived for about 4 months. At first, the little guys did swimmingly, though there was a little hen-pecking, but nothing out of the ordinary. <Mmm, am not so sure> All the fish eventually cooled down and ate like pigs, though I never overfeed, and all seemed happy. About a day ago I noticed 1 of the 4 damsels swimming at the bottom of the tank, not wanting to leave the place in which it was swimming. It also didn't eat, nor did it swim around with the other fish. <Bad signs> I was concerned, so I checked the tank, nitrite and all, and it was perfect, so I was baffled. Then, this afternoon when I came home from Church, I noticed another damsel doing the same thing as the first one, and they both are less than two inches apart. They exhibit the same behavior, swimming in isolation at the bottom of the tank. But what is odd is that another Damsel seems to be watching the both of them, without relent, but he never touches the two. I'm honestly baffled, and I'm not sure what's going on. <Have seen this... can guess...> I've had the other two damsels for several months and they are perfectly fine, and so are the other 2 of the 4, but the other 2 concern me. Also, I nearly forgot, that the 2 that are acting odd, seem to go through moderate color changes, going from bright neon to cold blue. <Good observation> They both are very aware of the other fishes, and of me, but they are not interested in food or swimming around. I've also noticed that they stay within an area where there is a dip in the crushed coral, but they don't always stay in just one spot, but never far from. The tank is full of live rock, but it lacks any living corals and the like. I wonder what is wrong with my Damsels, are they crowded in my elongated 45? <Yes> To note, the other fish have eaten, and they seem very normal, and its been nearly a week since the initial placement of the fish(They were in a separate tank, for about week, by themselves for good measure.). Any comments would be great, Michael Flanigan <I do think that the social dynamic... the size, shape of this system is limiting here. I would move the two "out of sorts" specimens from this system, pronto. Bob Fenner>

Re: Odd Damselfish? Worm internal infestation  12/19/08 Hello again! I did what you told me to do, and I'm glad that I did. An amazing, you will loose the exciting shrill in a moment, thing happened after I removed the two odd Neons, for they exploded, or I should say, released havoc on my empty 20 gallon tank. I woke up the night after placing them in their new tank, and I saw the most horrific scene, worm-like-creatures coming out of the vent area and other openings of the fishes. It was horrid! <Yeeikes! Have seen this... on a few occasions... Lots of white, no apparent head... Nematodes...> I called my LCFS and told them what was happening to my poor fish, and they were horrified. They, my LCFS who are my close friends from college, recalled seeing the same thing issue, for they must have infected the tank where a new stock was placed from which I bought from. I feel bad for them, but I they would have contacted me if they'd had known. In short, I hope this is common enough where it is treatable and known, if not, I pray no one else goes through what I did, I had to put the other one to sleep, I'm still sad about the whole mess. This has brought me into a bit of a frenzy though, for my 45 gallon tank where the two once stayed; I fear that the worms may have spread to my other fish, but at the moment they don't show any signs of the problem. I wonder what I should do, I don't want to be brash about my 45, but I fear for my fish and it would kill me to see the same thing happen to them. What should I do? <Mmm, some of these worms are rather species specific... But I would treat with a vermifuge... Lots re here: http://wetwebmedia.com/fshwrmdisfaqs.htm and the linked files above. Bob Fenner>

Damsel moving substrate 03/20/2008 Just wondering if you know why my damsel carries the substrate from one corner - almost like making a hole - and then spits the coral out? <<Ahh yes...fun to watch.. Its building itself a den to rest in...quite common for damsels to do this. Some even go as far as adding larger particles of sand / coral chips to help the fish>> Loren <<Thanks for the question. A Nixon>>

Damsels Acting Weird 1/16/07 Hey, <Hello.> We just got a new salt water aquarium. We filtered the water for one day, 5 gallon tank, second day we added 4 damsels(3blue, 1black and white strips) in our tank, <Yikes! In a five gallon?> they were enjoying. I used to put one pinch of food every day. after one week I changed the 50% water and added new salt water with that I added two yellow damsels .Total of 6 damsels. <Way too many in this tank.> This is what happening in the second week, one of the damsels died (out of the first 4). <This is to be expected.> the remaining three are lying down close towards the sand and not coming up. the new yellow one is just facing down (with mouth towards the sand and tail on the top), it is moving but not the way it is supposed to go around. Thanks, Purna Bhat <First of all, you do not mention the filtration you have on this tank. Regardless, you should not be adding fish so soon, nor in this quantity for this tank. One damsel at most here, and even then certain species will outgrow this tank. You need to read through WWM regarding stocking levels/tank cycling and research you selections for this tank. Systems this small are inherently unstable and your livestock must be chosen carefully. I suggest that you start with the link below. Please also use your spell/grammar check in future correspondence. Thanks and good luck, Scott V.> http://wetwebmedia.com/stocking1.htm

Re: Damsels Acting Weird 1/17/08 Dear Scott, I know we did a mistake by taking a small tank and added more fishes into our tank. Quick question on my Damsels- One more yellow fish died today, Is there anything I need to do so that no more fishes die in my 5 gallon tank. <Let it cycle, depending on the filtration, and stock at appropriate levels.> Do I have to shut off the lights of the tank (or keep it On for few hrs) Any specific food I need to feed for them. <No, but feeding sparingly, making sure all food is consumed will be very important in a system this size.> Where can I buy a big tanks (which will hold 10 fishes) with all the stuff that goes inside for a salt water <Depends on where you are located. Local fish stores will be your best bet. Look in the phone book under Pets and Supplies. You can also find tanks online, but shipping makes this an expensive way to go. Best of luck, Scott V.> Purna

... absurd... This tiny crowded system with damsels will not ever/never work out... RMF.

Sand Disturbance in the Tank 12/31/07 Hello, <Hello.> First of all, I would like to thank you for your brilliant idea of letting every aquarist asking you this "free" way. It's really very useful. <Very welcome, a joy to be part of.> I used to have a fresh water aquarium then I decided three weeks ago to change it to a marine one in my 50 gallon tank. I have an external filter along with an internal one that is built in the cover of the tank. Moreover, I'm waiting for a "Typhoon" skimmer to be shipped to my place. I have put natural sand in the bottom of the tank and put some small colored rocks from the red sea over it. Finally I have some blue damsel, clown fish, and a couple of relatively big butterflies. <After just three weeks?> My issue is that the damsel (specially the bigger ones) usually goes down to the bottom, shakes its body against the sand, and disturb it which makes the water sandy and hence reduces its quality along with my joy! <Yes.> Is there a solution? <No.> Is the habit of "shaking the body against the sand" related to some types of fish? <Yes, damsels being some of those fish.> What can I do? <Return them to where you got them if it bothers you. Do consider also returning the butterflies, your tank is too new. Rock to cure, filtration to cycle. It sounds as though you may have collected your own? This would make returning them that much easier.> Best Regards, Amr <Good luck, Scott V.>

Friendly fish, Damsels... beh. & repro.   12/27/07 Morning Crew, Hope you all had a great Christmas. <And you and yours Dan> I have an unusual question for you I have a Azure damsel and a Yellow tailed damsel that have become quite friendly. Oddly enough I have a 3 Striped damsel, and a 4 Striped damsel that have also become friendly with each other, both in the last few weeks. <Does happen... many Pomacentrids are quite social with their own, similar "kind"... and they can't see themselves generally...> ( A little history, not sure if significant or not, around the same time I switched to metal halides and by suggestion of my LFS I also removed all of my substrate, it had been in the tank for about the three years I had been running it, I had done some partial changes but never a wholesale one. I could not get my nitrates under control even with the addition of a fuge full of macro, it seems that the nitrates were just seeping out of the substrate and never really going away, after talking and reading this seemed to be the problem [since then they are under much better control] also I wanted to move from a fowler to a reef set up and I new it was absolutely necessary to address this issue.) Well, needless to say they are laying eggs. Which brings me to the real questions in all of this rambling. What kind of time frame from when they are laid 'til they hatch? <Mmm... 3-4 days, depending on temperature> I have noticed in both cases they are gone after about 3 days, despite the diligent watching of their parents, I would not be surprised if something was getting to them, but the time frame in both attempts has been the same, could it be only a 3 day gestation period? <Yes> And could the lighting and water quality change have made them start spawning, both pairs have been in my tank since nearly day one? (3 of the four were my seed fish) <Yes> Thanks from a never ceasingly amazed fan. Dan <Thank you for sharing. Bob Fenner>

More Than One Tang Damsels as "Dither Fishes" Good morning, <Hey there! Scott F. in today!> I usually rely on your website for a source of information... but also have Bob's book by the TV to peruse during commercials. <Good for you, bad for the advertisers!> In Bob's book I noticed something that I haven't seen on the website... a comment about adding a school of damsels or Chromis to reduce aggression in a tank. My current inhabitants of my 200g tank / 50g sump / 210lbs liverock: 1x Medium/Large Snowflake Moray Eel 1x 5" Magnificent Foxface 1x 5" Harlequin Tuskfish My wish list in the order of introduction would be: 1x Tang 1x small Picasso Trigger 1x Angelfish (species to be determined but one that would not grow beyond 10" at adult stage). <OK- a crowd that needs space...I would think about limiting my stocking list to those fishes...> I like Tangs, and ideally would like to add two. I've read many of the FAQ's regarding Tang conflict... but then again read just as many stories of people with two or three Tang's that are compatible. I like the Regal Tang... but now that I've seen a Kole Tang in action... am thinking that a Kole Tang or Chevron would do wonders for my 200g tank algae issue. Would two Tangs fit in to my system without overstocking my tank? <I think you could only do two of the smaller ones (like the Ctenochaetus species. Even then, I would be hesitant in a system stocked like yours.> What are a few pairs you could recommend that would LIKELY fair well together and with my stock? <Maybe the Yellow Tang or a Kole Tang> Can you expand on this idea of introducing damsels/Chromis to distract and reduce tension among the larger fish? If I was to go with the aforementioned fish list with the second Tang, could my tank handle a small school of Damsels? Chromis? What would you suggest? 3?? 5?? <Odd numbers definitely work best, IMO. This will provide both sufficient damsels to diffuse aggression, as well as to discourage the damsels from picking each other apart!> I'd stick to the smaller species and away from the Sergeant Majors, etc. What are some good schooling fish that are small, feisty, and alert. I did have two blue yellow-tailed damsels in with my Snowflake Moray for 3 months and he left them alone. I'm very much intrigued at this idea... please tell me more :) Dave <Well, Dave, the species that you selected are quite useful for this purpose. I would take into account the fact that they are beautiful and interesting fishes in their own right; I really like them for color and behavior. Their activities can draw out shy fishes, and help diffuse aggression in an established system. Remember, they can also become victims of aggressive fishes like the Tusk or the Trigger, so do show some compassion for them when working them into your stocking scheme! Best of luck! Regards, Scott F.>

Re: More Than One Tang Damsels as "Dither Fishes" (cont'd.)  12/24/07 Thanks... <Glad to be of service!> So, add Tang, Trigger, Angel... and I'm done. Would 3x Yellow-tailed blue damsels work in with this and I leave the second Tang out of the picture? <I'd think that this would be a sound strategy.> I'm thinking that the 3x damsels would actually assist in keeping the tank clean by going after the food scraps/leftovers leaving less waste? <I suppose you could make that case, but in the end, they are still active eaters, and consume lots of food, so I suppose the case could be made that they will eat much of the uneaten food in the system. However, they will, of course, metabolize the food and produce waste!> I imagine the Trigger is somewhat messy as the Snowflake most certainly is... and the Tuskfish doesn't have the best of table manners either. Or bad idea for 3 damsels with the Trigger? My single Yellow-tailed damsel that's currently in my 90gallon reef tank was actually housed with the Tuskfish before and was left alone. Thanks again! <Again, I'd add any smaller, potentially "edible" fishes with caution. The Tuskfish or Trigger could suddenly develop a "taste" for his/her tankmates at any time. Just look out for potential signs, like chasing or "stalking" behaviors, and be prepared to remove the Damsels for their own safety. Good luck! Regards, Scott F.> Microspathodon dev.   3/21/07 Help Please, <Okay> I have a 90 gallon FOWLR tank, with a Eheim filter, a red sea prism skimmer, <Company names and their products are proper nouns, capitalized> one 1200 and one 400 powerheads , a blue green Chromis, a blue devil damsel, <These are social species, should be kept in schools> and one jewel damsel. <Not this one> My water is excellent, with 10% water changes each week. Two days ago, I noticed my jewel damsel started losing the color in half of its body from its head backwards, and seems to be swimming in the stream of the 1200 powerheads, none of the other fish shows signs of disease. It is still eating and moving around. I have ruled out Ick, with no visible spots on the fins or tail, Im stumped. <I'm... note the use of the apostrophe, am not... Please see WWM re this species: http://www.wetwebmedia.com/microspathodon.htm and the linked files above. Natural color/pattern change. Bob Fenner>

Cleaner Damselfish  2/22/07 Hello Bob and Crew, <Hi, Pufferpunk grabbed this one from the Inbox.> I have written in before about my Stars and Stripes Puffer, "Blinky" and his odd behavior of suddenly and quickly diving down and scraping his belly on live rock and coral gravel.  Bob suggested that he might be reacting to his own reflection, although I pretty much ruled that out after hours of observing him (mostly because he will be positioned at one end of the tank and starring down the full length of the 48 inches of tank with rock, and other decorations blocking his view.  He also positions his body vertically, looking straight down at the gravel, hovering for several seconds before he takes his dive).   <Goofy, puffer-antics... or an itch caused by parasites.> Additionally, his appetite and every other part of him remains normal.  Anyway, he was doing it so much (several times trying to jump out of the tank and violently hitting the glass top) that it became disturbing to witness.  I actually had to leave the room.  I thought I had a suicidal Puffer on my hands.   <Many a puffer has been known to go carpet-surfing.> However, refusing to give up I tried putting several small fish (Damsels) on his side of the partition.   <Partition?  How large is this tank?  Your S&S puffer will grow quite large, requiring at least a 180g tank.   See: http://www.thepufferforum.com/forum/ug.php/v/PufferPedia/Marine/A_Hispidus/ > The reason for this?  The first several weeks I had him, he was enjoying the general population and full run of the tank (pre-eating and killing my LTA) <Most puffers are NOT reef safe.> and he never engaged in this odd "diving" behavior.  I thought, "Is it possible that he is lonely?"  To make a long story a tad less long; I put the two fish on Blinky's side of the tank and it seemed to have a calming effect on him almost immediately.  At that time I also realized that the Puffer was looking a bit "raggedy" from repeatedly scraping his delicate underbelly on the jagged rock and gravel.  There were no actual lesions or anything resembling an open wound, though.  If I had to describe it I would liken it to a close shave (human) resulting in some flaky skin.  Blinky literally had flaky pieces hanging from his chin (mostly) and some from his belly.   <More proof of parasites IMO.  Their skin is not delicate, actually the opposite.  More like prickly leather.> I was recommended by my LFS to put a cleaner shrimp in with him to attempt a cleaning (before the poor invert was gobbled up as thanks; not a consideration).  But then several days ago I noticed the small Humbug damsel was gently taking small, swift nibbles at Blinky's underside.  In fact, every piece of flaky skin was gone and the Puffer was looking clean as a whistle.  He was even hovering, completely motionless, seemingly enjoying the service AND the attention.  This service/relationship continues almost a week later.  Although occasionally one little nip may seem a bit too hard for the Puffer and he will wince a bit and shake his head back and forth like a Ferret.  I don't think it is an aggressive act, nor do I believe that either fish believes that it is aggressive (the Puffer has never tucked is tail into his body as he does when upset or intimidated during any of this).  But I have read about Puffers having skin and not scales and that their skin is sensitive.  FINALLY - MY QUESTIONS.....Is the current Puffer/Damsel relationship worth the risks?  Is it a true symbiosis or freak of nature?  I have heard of cleaner shrimp, but don't have any knowledge of cleaner Damsel fish.  Is it unusual for a Damsel to engage in this type of behavior?  So, what are your thoughts on this odd relationship?  Should I separate the two or give it some time? <Very common for a smaller fish to become the cleaner of a larger fish.  One of my favorite places to hang out in the ocean on a dive, is the cleaner station.  Sounds like the puffer & the damselfish know their place & the puffer will let it stay that way... for now... you can never trust a puffer!  Check out www.thepufferforum.com, for more info on your puffer.  ~PP> Thanks for enduring my long tale! P.S.  Bob - enjoying your book immensely! <<Ah, good. RMF>>

Strange Damsel, Actually Mean Damsel 2/14/07 I recently wrote about a crypt problem which I am glad to say I have got cleaned all up. <Good> Which brings me back to my Domino Damsel (2in) who keeps rubbing on my Foxface Lo (4in).  Its almost like they are playing the Foxface will turn on its side and the Damsel will just run into his fins and rub all over him. <Not playing, aggression.>  He started this right back up after I reintroduced him into my main tank.  <Reestablishing dominance.> I'm really not sure what to do, and if I should let it continue.  <Will negatively effect the Foxface over time most likely.>   I really have no where else for him to go. <Back to the shop?> So if you have came across this before I would like to know the response.  Thank You. <That is why damsels often prove to be problematic, can be very aggressive even to fish much larger than themselves.  Most likely will need to be separated in the near future.> <Chris> 6 year bullies, Amblyglyphidodon aureus ! Need to trap some fish - 1/22/07 Hello everyone!! <Hi Pam, Brenda here> I have learned so much from you guys.  Thank you for such a wonderful site!! <You are welcome and thank you for the positive feedback!> I hope you can now help me with the following problem. It concerns this bully, Amblyglyphidodon aureus! I've had two of them for about six years!  They bullied a beautiful little pair of tangs three years ago, and chewed them to the point of no return.  Through the years, I haven't been able to keep any other fish in my 75gal reef tank.   This week however, I decided to give it another try, and purchased six Bicolor Pseudochromis.  So far, the bullies have chewed the fins on two of them so badly; I fear they will not survive.   <Ouch!!> Along with the chromis, I bought six very small Tomato Clownfish - Tank-Bred.   <Yikes!  Twelve fish all at once?  Too many!  Also that is too many clownfish for your tank.  I suggest no more than two clownfish together.  You will likely see aggression as they mature.> Again, I was hoping for power in numbers, but that doesn't seem to be the case here, with bullies like the Amblyglyphidodon aureus. They are being harassed to no end! Now, for my question:  Is there any such thing as a "fish trap"? <Yes> Yeah, funny question, but try catching these! As soon as they see the net, they duck for cover with the speed of lightening!  I must get rid of these pests! <Try searching the internet for fish traps there have been many who have made their own.   They are also available at www.marinedepot.com, and possibly at your LFS.  I suggest separating as many as you can from these damsels, ASAP.  I wouldn't add more than two fish at a time to your system, and this is after they have been quarantined for 30 days.  Fourteen fish for your system is too many in my opinion.> I don't have a refugium set up at the moment (that's another problem!) however I do own a new one. <A refugium would be a nice place to house some fish until you can find someone to take them.> Thank you for all your help!! Pam <Your welcome and good luck!   Brenda>

Damsels/Growth Rate 10/9/06 I'm just starting out with a 75 gallon tank and have 8 damsel fish, they are about an inch long.  How quick do they grow? <Read here and linked files above. Should lead you to the info you seek.   http://www.wetwebmedia.com/damsels.htm Thanks! <You're welcome.  James (Salty Dog)>

Question about Neoglyphidodon melas, beh.   8/24/06 Hello, <Hi there> Thank you so much for your WONDERFUL website.  We have a 55 gal tank that we've had up and running for 17 years now. <Neat>   Currently in the tank is a geriatric (in age, not attitude) percula, 2 domino damsels and a Neoglyphidodon melas (found out what it was thanks to your site - LFS said it was a green Chromis, NOT).  We'd been down to just the perc for a while and decided to get some friends.  We added the N. melas, then a week later the 2 dominoes. <This last species can be a bug-a-boo... mean> When we got the N. melas at the LFS, it had the juvenile coloring.  In the car on the way home, he was darker, I figured just freaked out about being fished out of the tank and plopped in a bag, well, he never went back to white. Upon entering the tank, he ate well and is showing no signs of stress.  In fact, he seems to have made himself top dog. <For a while... till the Dascyllus grow...>   The perc seems to be tolerating him, they do the shimmy thing at each other, but no nipping and seem to have separate 'territories'.  The dominoes came later and are smaller. <... for now> This is my question:  Could the N. melas have gone thru puberty in minutes like that? <!?> I mean, he was white in the store, dusky in the car and dark blue/black by the time we hung the bag in the tank! Possible? Mimi K <Sort of... the colors expressed can/do change in terms of the fishs perceived status... Bob Fenner>

Re: Question about Neoglyphidodon melas, beh.  8/25/06 Thanks so much.  We're aware of the feistiness of the Dominoes. We've had them before and really wanted to get another after losing our Slider after 9 years.  He was full of attitude but that really made him the star of the tank. <O...kay...>   Surprisingly (or maybe not to you), he and the Perc got on quite well. <Happens>   I'm hoping it'll be that way again. <Me too> The perc did ram a tomato clown till he went blind, so no more clowns for us. On the N. melas, we've had him for about a week now and he's stayed dark.  So interesting.  A first for us.  We've had a tank for a long time, but tend to stick to the beginner fish.  Twin toddler and an infant REALLY take time away from the hobbies... Thanks again. <I can only imagine. Cheers, BobF>

Forget "White Punks on Dope", it's Damsel on Crack   8/23/06 I am so green on this hobby but have a brother offering tons of advice and doing well.  I have visited this website extensively since starting the small 40g tank and it has been a tremendous information tool. Thanks guys. <And gals...> I have no issues with water just tested by the store and they didn't provide me with the #s but said you look groovy. <Eats shoots and leaves...> I have two yellow tail blue damsel, sorry no picture with me this sec and I do not know the scientific name.  One of the damsels appears to during the night loose all of its blue coloring plus is like all over the place on speed or red bull. <Happens... don't like the light suddenly going on/off... sees reflection/s...> I notice this for the past two mornings.  I would turn on my living room light to take out dogs and by the time I leave for work the damsel is back to original color.  It seems to just settle into hanging out with the other fish.  Couldn't really tell you how long this has been going on since last week (first week of school) during the a.m. I didn't look in on them. What is up with this color changing and high velocity swimming?   <See above... natural reactions to unnatural stimuli> I have had the tank since the first of July, not sure if listing of inhabitants is necessary but here they are live sand, live rock, two blue damsels, two "not sure type of damsels" (light pink and yellow-black dot), three skunk shrimp and two peppermint shrimp and three snails.  I had two Dalmatian mollies as my start up fish that the last one just past away this Saturday one previously died two weeks ago. I was going to move the mollies to my daughters freshwater tank but it was having issues so I did not make it in time to save the molly. FYI, magnum filter, Bak pak, AquaLight (not lunar) can't remember all the specs sorry.  Hikari small red pellet food, some flake food and every once in awhile a few shrimp, temp 77;78.  Last water change was on August 12. I also had two zebra(?) Damsels that both died within like three days of each other.  All the damsels were purchased at the same time at the end of July.   They were the first fish I purchased because they were supposedly hardy.  I was warned that the black and white damsels can be aggressive for territory but this didn't seem to be the case.  The remaining 4 damsels appear to be growing and seem oh so happy.  Also any special vitamins/supplements you would recommend. <Mmm, this system is too small to mix these Damsels in in such numbers> Saturday after the water testing I purchased a small anemone and a red saddle clownfish.  They are in love, it's too funny.  The anemone has settled in and appears to not be opposed to all the rubbing of the clownfish, is this okay.   <...> Any advice, harsh or otherwise is greatly appreciated. Laura Kristin <Please read here: http://www.wetwebmedia.com/marine/fishes/part2.htm the tray at the bottom, on Damsels... re their Compatibility... Anemone Hosts of Clowns... Bob Fenner> Re: Damsel on Crack   8/23/06 Thanks for the response, which just allows me to purchase an additional and larger tank. <Heeee! I like the way you think.>   Sorry for the guys reference, I am a mother and still called dude from my kids.  Hope not to offend anyone. <Mmm, nah... just our/my ongoing crusade to credit all! BobF> - Fading Damsel 8/22/06 - Hi, What would cause a Neon Damsel to fade color? The fish still eats, he was bought along with another Neon Damsel about three months ago, they were the first additions to the 240 tank. The other Damsel still looks good. The faded gray looking one hangs out under the rocks, so it's difficult to get a good look at him. The tank is in the process of being changed over to RO water, since there is a problem with alkaline water and a high PH. As of now, about half has been changed. The fish has had this problem for a couple of weeks now. Any advise is appreciated! <My best guess is that the faded damsel is getting his head pounded in by the darker shaded one... this is way of things with damsels, especially when their numbers diminish - they tend to focus down on the remaining members of the group. Would probably dissipate if you put in more damsels, although I can hardly recommend that long term. Best to let this take its course.> Regards, Terri <Cheers, J -- >

- Fading Damsel, Follow-up 8/22/06 - Hi J, <Hi.> Thanks for the advice on the Damsel. <My pleasure.> Damsels are colorful, cute and pugnacious. Not to mention hardy. <All of the above.> Glad to hear it's not a disease problem. <Didn't sound like one...> Speaking of, some of the fish are scratching against the rocks, is this something to take quick evasive action on? <I'd keep an eye on things... if these are the only fish in the tank I'd for certain ride things out. Damsels often flash against decor, but if this happens more and more often you may want to consider your next steps.> Best, Terri <Cheers, J -- > Chromis Acting Weird   7/8/06 Hello to all of the Crew, <And you> Long time reader. First question. We have 2 tanks a 55 gallon and 75 gallon. We established over a year. We do regular water changes and have our water checked weekly. <Best to do this yourself... samples "change" with time, transport...>   It's always fine. I try to stay on top of everything and spend time daily watching my buddy's in each tank, and so we don't have any problems.  The question is on our 55 gallon reef tank. We have 3 Chromis that have been together for a year now and the biggest one started going in the corner and acting weird. At first I thought he may have gotten too close to the Foxface. She's sweet but accidents happen. <Yes> That was a month ago and we re-checked our water and everything's fine. Well two days ago, I find one of them on the bottom in front towards the corner acting the same way the first one does. The third one is the only one going into his little place at night the other two stay in the corners.  Now this a.m. the third one isn't coming out he's staying hidden in the back. Everyone else in the tank is doing fine. Help. We have a Foxface, small Wrasse pink with yellow fin, Cardinal, 2 cleaner shrimp, lazy brittle star, hermits, snails, oh and a fat lawnmower blennies, scooter blennies. Nothing has been added to this tank. And most have been in there a year or right at a year. Any advice is much appreciated. Thanks, Tere, Eddie & our fish Buddies. <Nothing "jumps out" as a problem here... and of common issues, some of the other livestock listed would be mal-affected first. It may well be that these Chromis damsels are just "getting old"... only live a few years... Bob Fenner> P.S. We have Rat Terriers and one of them, Betsy loves to watch the fish with our grand-daughter or by herself. I think she misses dripping them in. Because we sat the 75 gallon up and she sat with each fish while they dripped. <Neat>

Damsel Problems 5/28/06 Hi everyone. <Hi> I have a 29-gallon fully cycled saltwater tank that has been set up now for about 4 1/2 months.  I have 2 yellow-tailed blue damsels, 2 "Nemo" clownfish, one rusty angel, and one royal Gramma. <A lot for a 29>   My water parameters are: temp:  78-80 degrees salinity:  1.020 pH:  8.2 Ammonia:  0 Nitrite:  0 Nitrate:  0-10 <Ok> A few weeks ago, I had to return one of the damsels to the fish store because he was being repeatedly harassed by the other damsels.  Everything seemed to be going well since then (and all seemed to be quite peaceful) until today, when I saw that one of the remaining damsels has been beaten up by the other damsel.  I know it was the other damsel because, even as I watched, he continuously picked at the injured fish.  The injured damsel looks pretty bad right now and I'm concerned he may not make it through the night. <Let's hope> If the injured damsel survives, I plan on returning him to the fish store as well.  My question is:  If I keep the one remaining damsel, is he going to continue his pattern of harassing the other fish for the rest of his natural life, or will his size prevent him from wreaking any more havoc with the other species?  Should I just return him as well? <I would.> I'm also considering getting a six-line wrasse, especially if I return the remaining damsel. <Wouldn't, enough in there as is> Do you think there will be any problems with aggression from the wrasse, given the mix of fish that I currently have?  <Yes> I have not had any problems with the clowns, the angel or the royal Gramma (all of which seem to be pretty peaceable). <More likely all terrified by the damsels.> Thanks!! Pam <Sounds like typical damsel behavior, they are mean.  The aggression is heightened by the high bioload in your tank.  In my opinion the tank would be best off with just the clowns and Gramma.  Otherwise territorial disputes will continue.> <Chris> Chromis Behavior   2/26/06 Hi from Atlanta! <Hello backatcha from S. Cal.> My 90 gallon reef is about 8 months old.  Inhabitants include: yellow tang, blue tang, 2 gobies, 2 clowns, 2 green blue Chromis, an old one eyed sergeant, <Named Sgt. Lucky?> orange star,  serpent star, yellow tailed blue damsel, and lg. Potters angel, <Oooh, not easily kept> an anemone, and various corals.  Everyone seems to get along well.  My question relates to the green blue Chromis.  Late in the day they tend to get very active and playful? <Me too> They swim up to each other at a high rate of speed and kiss.  Is this all in fun or what? <Fun plus... spawning, et al. behavior> One is larger and definitely dominant but never attacks the other.  Thanks in advance for any info you can share!! Katie <Keep watching! Bob Fenner> Gold tail damsels changing colors  - 02/25/06 I am cycling a new 110 gallon saltwater tank. <There are other, better ways w/o fish present> I notice a couple of days ago that my one gold tail damsel was getting darker while the other stayed the same color.  I  test my water to see if there are any changes.  Everything is cycling as normal.  PH @ 8.2,  NIT @ 10, and AMMO @ 0.1  The darker on eats normally does seem sick.  But now i notice that the damsel that was normal colored is slow becoming darker.  I've looked all over to see if they change color as they mature.  I don't think they should.  Could they have an internal parasite that could cause a color change? Heather from Wahiawa, HI <... could, but much more likely just stress-coloration from being present in a toxic environment. Please read here: http://wetwebmedia.com/estbiofiltmar.htm and the linked files above. A hu'i hou! Bob Fenner>

Disappearing Damsels    1/25/06 Hi, I am new in the saltwater world.  I am in my 7th day of cycling with 1 blue damsel, 2 yellow tail damsels, 1 black and white stripe damsel, and 1 black with white dots. <... not advised to cycle with fishes... disease issues, unnecessary/cruelty... posted on WWM> On day six, when I got up and looked in my tank, (150 gallons) one of my blue with yellow tail was gone with no sign of him.  I have looked around the tank and all under the rocks and decor in the tank.  Today when I got home from work, all four fish were there.  I fed them and then went back over to the tank and my black with white dots was missing.  I looked under all the rocks and decor and still did not find him.  I have an undergravel filter (I know everyone says to not use them, but I had it so I used it) <Can/do work... also posted> I also have a Rena xp3 filter, and the intake is too small for those fish to go through.  All of my uplift to my undergravel filter has the top on them, so no way they could go down them.  I have about 3 inches of crushed coral, no live rock.  I started the cycling with 5 damsels and a couple hands full  of sand from the fish store.  Can you shed any light as to what happened to the fish.  Thanks, Kathy <Hiding, or dead/dissolving. Bob Fenner> Re: Disappearing Damsels    1/25/06 Hi, I don't think they are hiding as I have turned over everything in the aquarium looking for them.  Can they dissolve that fast within minutes? <No... several hours though> I have had freshwater tanks before and dead fish don't dissolve that fast. Thanks for the info.  Kathy <Any smiling kitty cats about? I'd look on the floor next. Bob Fenner> Damsel behavior, (in)compatibility  - 01/24/06 I bought 4 damsels Smallest to Largest (Blue with yellow breast, 3-Stripe, Domino, Yellow with slight pink color to tail). after completing Live Rock cycle. I have had them approx a week. The yellow in color. It has been digging the sand all the way to the bottom. I have covered these holes but it continues to dig. Is this normal. Is this fish going to lay eggs. should I continue to fill the holes? Les Miller <Is normal... but this mix of damsels is not... Bob Fenner>

Damsel Behavior... In love or fighting?  - 01/24/06 I have looked all over the Internet trying to find out what my damsel is doing.  One damsel swims in front of the other and seems to swim up and down repeatedly.  I have no idea why it is doing this... (doesn't seem to be aggressive).  Please give me an idea. <While there may be no apparent aggression, this does sound like a display, to "warn" the intruding or competing specimen. If it is not aggression I would surmise it is some type of courtship. Adam J.>

Damsel fish respiration/breathing rate  1/11/06 Hi, <Hello Chris> I have 2 humbug damsel with what I think looks like high respiration.  I know lion fish normal respiration is 30 breaths per minute, could you please tell me what the normal respiration for a damsel fish is per minute, thank you <The humbug is rather active and what you are seeing isn't abnormal.  I really don't know what the respiration rate is, never checked.  Please do not ask what the blood pressure might be:):) <James (Salty Dog)> Chris

Cycling without Live rock: You still don't need livestock  10/31/05 Hi, <Hello Patrick.> I will be cycling 135 gallon saltwater tank using the damsel method.  <O' boy.> I chose this method because I am unable to acquire live rock due to lack of money, and would like to have the damsels anyways. I am planning on using green chromis (Chromis viridis) to cycle the tank, so I can have a nice school of them later.  <Live rock and using fish are not the only ways to cycle a tank. You simply need a waste source, anything form a sample of substrate from a friends tank to some fish food will work. While live rock is the preferred media you can use other porous surfaces for bacteria to cultivate such as base rock and bio-media.>  <<LR provides an inoculation of bacteria, housed within its pores (this may or may not include the anaerobic bacteria necessary to further break down nitrate into its individual components).  It does not provide the bacteria with food sources sufficient to maintain the colonies in situ, or to bring these colonies up in numbers sufficiently in order to add fish and avoid the rise in nitrogenous wastes.  A sample of substrata would again be used to inoculate, but does not provide food sufficient to maintain or bring up the size of these colonies.  Food that will decompose is what is necessary.  MH>> How many of these fish would you recommend using?  <None.>  If I don't only use the green chromis, I am considering doing a combination of both green chromis and blue reef chromis (Chromis cyaneus).  <May run into problems with that mix.>  If I do the combo how many of each fish would you recommend?  <To cycle? None.>  And would they school separately?  <Have not personally observed this mixture in captivity but generally schooling fish tend to "just-hang-out" in captivity, excluding very large tanks.> Thanks, Patrick <Research WWM Re: Marine cycling. You're welcome, Adam J.>  

Damsel in distress, Dascyllus are social animals  08/08/2005 Hi, <Hello there> I purchased a four stripe damsel five to six months ago and have had continuous problems with it ever since. When I placed it in quarantine and it always preferred hiding behind the heater or other equipment rather than the PVC pipes or the artificial branch coral I placed in there. <... Dascyllus are social species... live in groups> She has also always been a very scared fish, and always hides except at feeding time. About three days after I got the fish in quarantine dark areas started forming on the white stripes just behind the gill plates and the last white stripe on the tail. the fish has been this way ever since. By the way the fish did lose an eye while in quarantine from injury most likely while darting to a hiding place when I entered the room. I kept the fish in quarantine for an extra two weeks and administered a copper treatment because she just was not acting right. <Starting to sound like the U.S. military's confinement of folks...> The copper treatment seemed to work somewhat the dark spots became more vague, but did not disappear. <... poisoning> However, she was still a very scared fish. After a month in quarantine I moved her into a 46 gallon tank (where she still is) with live rock and numerous hiding places but she still prefers to hide in the equipment at the top of the tank except at night when she goes down to hide in the rocks. The dark areas are still present and seem to grow in darkness when stressed (during water changes and when I clean the glass). There are no outward signs or parasites, but I do sometimes see her scratching on rocks. She is the only fish in the tank. The water quality should be excellent (I use RO/distilled water) and all parameters are good and consistent. She eats and seems to be a very greedy fish and is not shy around feeding time. So my real question is what could cause all these symptoms and this extreme fear of people and movement. The best answer I can come up with is stress, but I can not find the cause. Please give me your opinion. Also would it be safe to add another fish in this tank with her in this condition. Thanks for the great service, Jed <Thank you for writing to well, thoroughly... to reiterate, the one simple fact that you apparently are unaware of is the need for others of their own kind... Take a look at Dascyllus species pix in the wild... they are always in close association with others of their own kind. Bob Fenner> Chromis Fish I had a Chromis fish that began to swim excitedly around the top of the tank making bubbles on the surface. It started gradually, then one day he went crazy racing around blowing bubbles. In the night he flipped out of a small space that was not covered and he died on top of the tank. My aquarium shop thinks he had a gill infection. I am not very experienced. The other fish, a yellow tang, a maroon clown, a dragon wrasse, two dart fish and a pygmy flame angel are fine. Do you concur? <Pretty tough to make that call without seeing the fish.  I'm thinking the maroon clown may have had something to do with it.  Was the clown aggressive toward the Chromis?> Could the fish have been saved if we had recognized the symptoms and quarantined him? <If you know what disease you are treating and the right medication is used.> Can this spread to the other fish? <Possibly> Is there some organism in the tank? <Don't know, not near enough info to make a call.> I appreciate your thoughts.  <Thank you.  James (Salty Dog)> Thank you, Kathy

Murdering Chromis (6/5/05) Dear WWM Crew, wondered if you had any ideas on dealing with a blue-green Chromis that has become a savage bully? <Get rid of it.> We didn't research things much when we made our first purchase of just 2 similar sized Chromises, but they seemed to get on alright despite not being in a larger shoal. Unfortunately we lost one of them to ich, but the other made a full recovery after treatment with copper. Worried that he might need some company, we purchased 4 more green Chromis from our LFS, who assured us that there shouldn't be any problems even though these were much smaller than our existing fish (c.1 inch vs. 2 inches). <Obviously, he was wrong in failing to consider that the remaining Chromis had established the entire tanks as his territory.> Right from the start he has been bullying his new tank mates, and there are now only 2 of the 4 left. We have separated them now, with the 2 smaller ones in a 60l quarantine tank, and the larger one on his own in the 240l main tank. The little ones seem much happier now, but we can't work out what to do in the long run. Should we try "feeding them up" and look to put them into the main tank when they're a bit bigger? or would it help to get 2 or 3 other larger damsels to try and "teach him to behave"? Any other ideas? Your advice would be, as ever, greatly appreciated, thanks, Jim+Jo, Norfolk, UK <Chromis, while relatively "peaceful" are still Damsels, and thus prone to territorial aggression. The simplest thing would be to catch him and give him back. The other thing you can try is to add a few new ones and significantly re-arrange the tank decor at the same time to confuse him so that he doesn't recognize his territory any more. He may then join the group as they will all be confused. This often works. The third option would be to catch him when it's time to put the others in and put him in the QT by himself for a few days so he forgets the other tank. Then you put him back in the main with the others after they've been there for a few days. Hopefully they all will then join up into one group. Hope this helps, Steve Allen.>

Lack of understanding re cycling, damsel behavior, lack of information on tank size, set-up, decor Hi, I just recently started a saltwater aquarium maybe 1 month ago... it is still hasn't fully cycled yet and I am using 2 fish to help speed the process. I have a false percula clown fish and a yellow tail damselfish. I'm having some problems with my damsel... I don't know why but when ever someone comes near the tank or I go to test the water he turns a blackish color. Is this normal and if not what can I do? Thanks a lot, Brooke <Mmm, is normal... for being stressed out, moved... in too unstable an environment... I would not use these or other fishes to cycle a system... Save yourself and your fishes real trouble and study... on WWM re cycling, set-up... Bob Fenner>  Damsels Hi, I've looked through your articles on damsels changing color, and they seemed to have changed towards getting lighter, however, mine (which I got like 3 days ago) turns black when the lights turn off, or if I go to check salinity, or whenever I disturb it too much...then turns blue again. Its really freaky. Is this normal?  <Yes, normal behavior. Please do cap your "i's" in future queries as we do have to edit these before posting to the FAQ's. It does save us time. Thank you. James (Salty Dog)> 

Damsel Trouble Hi.  <Hello> You guys have been a great source over the last two years but on this little issue I couldn't find any information, so here it goes. Two days ago I introduced a bubble tip anemone and a false clown to my recently upgraded tank. I already had two yellow-tailed blue damsels and expected the aggression that was to follow (I was a little irritated that the little monsters ate my new starfish, though). The Clown moved into the anemone a few hours ago (to escape the harassment), but one of my damsels seems to be unafraid of the anemone and has tail-swatted it several times in attempts to reach the clown. The anemone doesn't seem to be stinging the damsel. Regardless of how much of a pain this particular damsel has been over the last two days I am rather attached to her and I would hate to have her stung/killed by the anemone. The other damsel seems to be doing his best to steer clear of the anemone. Should I move the fearless little monster out of the tank for a few days or cross my fingers that the anemone remains passive to the damsels swatting?  <Don't worry, the little monster knows exactly what an anemone is, that's why he is using his tail, not much danger of a sting there. The yellow tail damsels aren't usually that aggressive. James (Salty Dog)> Thanks for being a constant source of marine education. 

Anemones and Blue Damsels Hi, <Hello there> I just recently bought a couple of blue damsels and a pink tip anemone. One of the damsels appears to be very attached to the pink tip. (Much like a clown with an anemone.) It even picks up food and spits it into the pink tip. Is this normal for damsels? I thought only clowns hosted but it sure is interesting to watch.  <Happens... Clownfishes are actually a subfamily of fishes within the Damsels... some damsels live in close association with actinarians... e.g. Dascyllus trimaculatus. Bob Fenner> 

Aggressive Yellow Tailed Damsel I just setup a new 30-gallon hexagonal (high tank) saltwater aquarium and began the cycling process last Thursday (2/10) by adding three yellow tailed damsels to the tank. Everything was fine until yesterday when one of the damsels started attacking one of the others by nipping its fins relentlessly. Ever since introducing the fish to the tank, I noticed one was more aggressive than the others, fiercely defending its territory in the tank. The one aggressive damsel gets along fine with the other damsel. I notice the aggressive one is also a deeper purple color than the other two. I separated the injured damsel from the other two. What do you think is causing this behavior? If the injured one survives and gets better would you advise introducing it back into the tank with the other two?  Any advice you can give is greatly appreciated. Thanks, Ken Jones <Ken, normally these fish get along well with each other and other fish. On the other hand the blue damsel (blue devil, appropriately named) is a different story. I'm thinking because of the small surface area of the tank, the aggression level may be elevated. I would probably remove the bully and put the injured one back in the tank. James (Salty Dog)>

Damselfish 3 Feb 2005 Quick question, I have 2 Yellow tail damselfish in my Eclipse system 12 tank, (only 2 damsels and 1 blenny in tank).  Every one seems healthy, and water conditions are ok.  But for the past few weeks the damsels loses color at night (when light is off) When I turn the light on in the morning they actually look like white fish with yellow tails.  Within about 15-20 minutes of the light being on the body turns back to the nice deep blue.  What the heck??  they are acting fine and eating ok.  Is this normal?? <Definitely normal. Its a type of camouflage that many marine fish have. Very wise of you to notice, Good luck, MacL> thanks for your time Steve Benedict

Fanning Sand Damsels, Nitrates Hi There WWM Crew. <Hello Marilyn> Happy New Year.  Love your site and have gained my knowledge from just reading. <Ah, good. Much better than errant experimentation> Also learned I did a few things I shouldn't have but that's before happening upon your site by accident.  Things are going well in my 60 gal. reef tank except that I can't seem to lower my nitrates 20 - 25 ppm even with l5 - 17 gal water changes weekly.  pH 8.2, CA 400-425, dKH 10-11 and alk. 3.7.  I have a CPR BAK-PAK 2R (reef skimmer) hanging on the back of the tank and a EHEIM 2215 canister filter running with approx. 100 lbs of LR and 2-3" of live sand.   Tank inhabitants:  2 ocellaris (Nemo), 2 green Chromis, l blue hippo tang (dory), l Neon Goby, l Orange Spotted Goby, l cleaner shrimp, l Peppermint shrimp, frog spawn frag, 2 different heads of candy cane coral frags, l Montipora capricornis frag, l fox coral frag, l really small Blasto merleti frag, l pagoda coral frag., several Pulsing Xenias and one 4 - 6" RBTA! Learned about  not "mixing" from your website after the fact but this RBTA has stayed put since it's introduction to the tank.  Thank Goodness.   <I see> My question besides above Nitrate problem is:  I've noticed my two Chromis for the past 2 days swimming from one end of the tank to the other together and then last night, together, fanning the sand front and center.  This happened maybe 2-3 times.  Why are they doing this?   <Social, pre-spawning activity. No worries> Also, swimming with them or close by is the hippo tang. Should I be watching out for anything. <You will see, everything>   I've never seen them doing this before.  My ocellaris uses it tail and body to clear/clean a spot in back of the tank but not like this.  Any help/advice re nitrate and this problem would be much appreciated.  Sorry to be so lengthy but thought you might need all the info/background. Thanks. Marilyn <Ahh, the nitrates (if they bother you) can be dealt with in a number of complementary ways. Please read here: http://www.wetwebmedia.com/nitratesmar.htm and as far as you want on the "Related FAQs" (linked, in blue, above)... until you understand your options. The behavior you can also cover on either the genus' (Chromis) coverage or "Damsel Behavior" on WWM. Bob Fenner>

Damsel Fish Color Loss  (12-3-04) We set up our 55 gallon tank about 2 weeks ago.  <Congratulations!!> We used live sand and live rock.  <Sounds like you are off to a good start.> We have 3 three striped damsels and 2 blue damsels.  The temp is 77 degrees, the ph is 8.3, the salinity is ever so slightly above 1.021, the ammonia was at 0.25 today.  Can you tell me why the color on 2 of my 3 striped damsels is fading?  Some of the white stripes are a light gray color and the black is fading.  Why do you think this is happening?      < Most likely the ammonia. The color change is likely due to the stress of poor water quality. There are also a few diseases that can cause color to appear faded. The ammonia should be zero. Please do a healthy sized water change and  review the articles on the WetWebMedia site, on cycling, the Nitrogen Cycle, biological filtration and toxic water conditions.> Thank you, Lisa <Your most welcome. Best of luck with your fish, Leslie>

Damsel losing color Hello......<Hi, MacL here with you today.> I'm wondering why my yellow tail damsel fish is losing some of its color from its lower lip down towards the bottom of its belly.  And the black stripes across its body seem to have disappeared.  Its freaking me out.  Your thoughts sure would be appreciated. <This could be a lot of things. The fish could be getting adult coloration. It could be caused by tank conditions. Do you think you could get a picture? That would help a lot. MacL> Thanks.

Re: Damsel changing colors. Hi Mac:  Thanks for your prompt reply. <You are quite welcome.> Unfortunately, I don't own a camera so sending you a picture is a problem. <I totally understand that.> I took some tank water readings this morning.  All were normal except for the ph which is a little high. <You know changes in ph could be a problem.  Wonder why your ph is high? Perhaps have the pet store run and advanced test on the water?> Some Proper ph should take care of that.  Perhaps I can contact the store that sold me the damsel fish.  The owner may know approximately how old the fish might be.  Any other suggestions?  Thanks again. <Other things that might be doing it are stress. Is any of the other fish bothering him?  They do change colors when they are mating, is he showing off to someone? lol.  If you want to take a look on www.fishbase.org you should see some adult pictures as well and that might help you some.>

Air bubbles and fish spots... Hello crew! I just want to say thank you for all the time and support that you and your crew provide to these questions.   I've been looking online for the answers to these questions, but I can't find the answers to my specific questions.   First, I have fine air bubbles returning to my tank clouding the water.  I know, don't say it; I have spent days reading the past FAQ's.  My particular problem is that periodically (every 20 minutes or so), a surge of bubbles enters the tank.  It's like the air is building up in the pump, then it spits it out. <Yikes, not good... can be dangerous to your livestock... there is an intake leak... somewhere... that you should look, listen for and fix... a spray bottle of water, a length of tubing... for spritzing on lines, fittings, the pump volute... and the tubing for listening for intake "hiss"...> I have siliconed all my joints before and after the pump and still microbubbles.  I don't have bubbles entering the sump so it is not coming from there.  I'm really out of ideas as where this air is coming from and how to solve the problem. <With someone helping, try pressurizing the line (blocking the discharge/s...) you may see water seep to shoot out of the intake source... otherwise try wicking a napkin/paper towel along the entire intake line... for water>   I have a 150 gallon with 100 sump below.   Second question is not a problem, I'm just curious if you have seen this before and what it is... At night, I often use the flashlight to see all the different life forms emerging.  I have six green Chromis and when I shine the flashlight on them, they have large 1/8 inch spots on the fish.  During the day, they have no spots and they are healthy.  Disease free for months.  Have you observed this before?  Normal?  Should I be concerned?   Thanks for your input in advance.   Dan <Likely what you observe, describe well here are "nocturnal markings"... changes in the fish themselves that may aid them in the wild in avoiding piscivorous predators. No worries. Bob Fenner> Damselfish troubles Hi there, I have a few questions regarding my 55 gallon salt water tank. I currently work in a pet store and have acquired this tank and decided to set it up as a salt water. Currently I have 1 tank raised clown 2 green Chromis 2 yellow Chromis 1 Diadema Pseudochromis (SP?) 2 blue Chromis and 5 blue legged hermit crabs 1 scarlet hermit crab. I just recently added a Condylactis anemone (pink tipped) and after putting it into my tank it floated at the top for awhile, after about an hour it started to settle and has now decided to attach itself to one of my plants and seems quite happy there. It this normal for it to be in the middle of my tank and do I have to worry about my other fish? << Normal, don't worry. >> It is smack dab in the middle of the tank depth wise and right in the middle length wise. My other question is, I had originally purchased 2 clown fish but the bigger of the two decided to pick on the smaller one and I have moved him into a 20 gallon sick tank, his fins are a bit tattered and I would like to eventually place him back into the 55 gallon. Any suggestions? << Put him in a breeding trap hanging on the tank.  That way the other clown gets use to seeing him around, but can't pick on him.  Also, see if that other clown tries to go pick on him again. >> I have one green Chromis that is swimming at the top of the tank and has seemingly lost a bit of his coloring, now a darker greenish grey color? Is he sick and should I move him out of my 55 gallon? If so how can I treat him? << No, just keep him there.  The stress of moving him is bad, and the color change may not be a bad sign. >> big thanks in advance for any help. Cierah <<  Blundell  >>

Demonic Damsels Strike Again Hi <Hi! Ryan Bowen with you today> I've had my reef for over 3 years, I had a half dozen or so tanks (fresh+salt) but now I've moved and consolidated to one 29g reef-tank. <Sounds good.> I've got a weird problem wish fish behavior. I have three anemones and they are all very polite. <Polite, yes, but if you aren't skimming furiously, there is invisible war being fought.> I have three fish and they are all quite rude. The fish wont leave the anemones alone, they are constantly pecking at the tentacles. Even when it is mostly closed and retracted they will carefully line up and position themselves (with a curious, intensely concentrated midwater hover technique I've rarely seen elsewhere) so as to get a peck or two at the parts that are exposed. I have a three-striped damsel, a blue velvet damsel and a 14 year old clown fish I got for free. I've had the fish from 6-12 months and the anemones for a couple years. I'm obviously more attached to the anemones, and I don't want any silly makeshift ideas like strawberry baskets interfering with their migration and movement. Can you suggest anything that would be causing the fish to do this, or any solutions? <Yes, remove the damsels!  They're trying to defend their territory...Encourage the anemone to choose a new home, but obviously the anemone cannot.  Permanent harassment will kill your inverts at some point.> BTW even after the fish have been fed they do this, its more of a social activity than a survival thing at this point. <Territory is survival in nature...sadly it seems, a luxury in aquaria.> Also, the clownfish does not reside in any anemone, the people who gave him to me did not keep any inverts and simply had a single fish in a tank for 13 years before they had to move. He has expressed no interest in any of the anemones, large tube worms or anything else aquarium clownfish are sometimes found basking. <Perhaps he's stressed- Remove the damsels and watch things settle in.  Cheers! Ryan>

Dancing Damsels (10/9/04) Hi, <Hello. Steve Allen tonight.> I have a yellow tail and a domino damsel in my tank (along with other fish). Recently I have noticed that every time my yellow tail comes out of his little cave, the domino will swim up next to it and the two will lean into each other and flutter their tails. They do not appear to be fighting, no tail nipping, or running each other out of their areas they just meet up and flutter their tails for hours sometimes. What is this? <Quirky fish behavior.> Any help would be much appreciated. -Susie- <Sounds harmless to me. Do be aware that Dominos are among the most aggressive of Damsels, so you need to be prepared to deal with eventual aggression should it occur.>

Other Chromis Schooling - 8/23/2004 Crew: This is a resend from last week (I totally understand things get lost). I am interested in the Black Bar Chromis (Chromis retrofasciata), and I was wondering if they are known to school in aquariums? <Mmm, not much... not as tightly by far as some of the more commonly offered members of this genus, e.g. C. viridis> While I am here, do most Chromis' school in aquariums (or the wild)?  Thanks, Rich <I'm guessing the propensity for schooling in the wild and captivity in this genus is split about midway... some are almost always found in close association in number, others more equidistant and reacting, challenging each other than moving in concert... much like Chrysiptera, or even Stegastes spp. damsels. Bob Fenner> Damsel in Distress (8/4/04) Hi, <Hi there. Steve Allen with you today.> Sorry but my four stripe damsel is not doing good. He is breathing hard and has rapid gill movement. Sits near the undergravel filter. I have a hang on filter and a undergravel filter. Specs on tank, Nitrate:40 Nitrite: 0 ,ph: 8.0; Tank size: 15 gallons, SG: 1.022, Temp: 77. Tank is cycled, fish have been in the tank for a while now,1 month. I have two blue devil damsels with him and they are doing fine. I really hope you can help me!!!!!!!!! <This is definitely a sign of distress. Many possible causes from low oxygen, to toxin to parasitic infection. The first two are less likely given that the other fish are fine. Assuming an ammonia of zero, your other parameters seem fine. Blue devils are known to be very aggressive. Perhaps these two are ganging up on the other? I would recommend removal to a quarantine tank for observation and treatment if signs of infestation (ich, velvet, etc.) appear. Read the quarantine articles and FAQs for info. Hope this helps.> 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

Damsels Hi, I was wondering about damsel fish. Can they also change from male to female like the clownfish? <Some species are known to do this> I would also like to know how many Dominos I should get for my ten gallon. Thanks <Actually, none... ten gallons is too small for even one specimen. You are encouraged to either look into other families of fishes (e.g. gobies, cardinals, blennies...) or save up for a larger system that will grant you greater latitude in species selection. Bob Fenner> Re: Xenia troubles

Man with 125 & 7 Chromis - 6/15/2004 Crew: I know this is unusual, but I am curious about a recent entry in the daily FAQ's.  The person's name was Malcolm Young, and he wrote that he has a 125gal.  Part of his fish stock included 7 Chromis.  I am considering a very similar stocking list, and I was wondering if the Chromis are schooling for him?  I will understand if this isn't something you post, so as not to turn this into a forum, but his stocking list is very close to what I am planning, I thought I would give it a shot.  If this is not proper, can I just ask this; has anyone experienced schooling behavior with any fish in a 125gal, 6 feet long tank?  Thanks, either way, Rich. <Mmm, well, we don't retain others email addys, but I'd bet his Chromis are schooling in this setting... and maybe he'll see your note and write in... Bob Fenner> Diggin' Damsel! Hey! guys, I just added some sand to my tank after having crushed coral. Anyways, my Snowflake Eel is way more active and he always swims in the water, sometimes for like 10 seconds. He'll swim with my other fish. Is the sand the big of a difference to him? <Well, it is easier on his skin, but the behavior may just be coincidental> Also, my Yellow Damsel keeps fanning big holes in my sand and exposes the bare bottom which I don't understand. I keep covering the hole up but 2 seconds after SWISH its back open. Is my damsel trying to find a breeding area? <An annoying, but common damsel behavior. This is generally done as a "nesting" behavior. This pit provides the fish a territory to retreat into, and eventually, a possible spawning site. Not a whole lot you can do to stop this guy from his excavating, so enjoy the natural behavior!> Thanks for taking time to read this, Aaron <My pleasure, Aaron! Regards, Scott F.> 

Blue School >Cheers! >>Greetings! >Silly question here, I like blue Chromis I have a 150 gallon reef that is just about cycled. It's lit and equipped for SPS (not that that has to much relevance). How many blue Chromis can I add to make a nice top water school? >>This is actually rather touchy, as many normally schooling fish *don't* school in systems with little to threaten them.  I would say, however, a minimum of five.  Don't be surprised if they don't school, though. >Looking for maximum effect but also plan on having other piscine friends.  Thanks, Brian >>Good luck, you would be fine with five to seven in this tank.  Marina

Help, Yellow tail Damsel  My damsel is currently changing colors. I have had my tank cycling for about three weeks. I have two damsels and several other fish. Well my damsels are getting healthy but they are changing colors. They appear to have lighten somewhat. Instead of blue they look a little light blue or possible purple. Help what is wrong with my fish or tank?  <Many species of damselfishes do change color substantially... depending on "mood" from water quality issues, tankmate interactions, feeding... Some are much happier in groups, rather than solitary... Bob Fenner>

Odd damsel behavior <Hi Sorry for the delay in response> I have a blue damsel that is not eating he is timid and does not bully as he used to he along with the others seems to have rapid gill movement but no other signs than I have had them all for about 3 weeks. <Well, damsels can be very timid when first introduced to the tank.  The damsels I have had in the past took weeks to fully become daring enough to swim around without darting into the live rock.  As for the rapid gills, perhaps you didn't allow the tank to fully cycle before adding the fish.  High ammonia, and Nitrites can damage the fish's gills, and effect the oxygen exchange in their body.  making them breath heavier, stay towards the surface, etc...> I used them some live sand and live rock to begin the cycle of my tank. I am very new to this hobby! I have been reading almost every night about saltwater tanks and their setups, but there are so many different opinions that i often get lost. I like the ones you have as they seem to be the most humane. <Thanks, we try to do our best to look out for the well being of the fish as well as the stress of the owners caring for them.> I have read hundreds of FAQs and post on your website many of them beneficial. I know you are busy so I was hesitant to write you. <shouldn't be hesitant, that is what we are here for!> I didn't quarantine because they were all purchased at the same time. <It's good to get into the practice of quarantining all incoming fish.  It can save you in the end!> I had six but two died in the first week mostly from aggression from the blue damsel described above. I am wanting to have a FOWLR tank it is a 75 gallon tank with two cascade 300 power filters (which by the way seem to work really well the tank seems to be cycled already but I am patient as money is not what I want to waste or just kill fish for the fun.) <75 will work nicely for a FOWLR tank.  Remember patience is the best think you can have in the SW hobby.> My levels are nitrite 0 ammonia 0 salinity is about 1.023 ph is a little low around 8.2 ppm have been trying to raise it to 8.4 nitrate is 10 ppm. <Levels are coming along nicely.> temp is 80 degrees is this a little high? <No, it's not that bad. I know  many people with tanks set at that.> If you can help thank you so much. <Be sure to keep reading the articles here, or check out the book "Conscientious Marine Aquarist"  it's a great publication that will give you some real insight in how to care for tanks.  Good luck. -Magnus>



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