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FAQs about the genus Chromis Damsels 2

Related Articles: Chromis Damsels

Related FAQs:  Chromis FAQs 1, Chromis Identification, Chromis Behavior, Chromis Compatibility, Chromis Selection, Chromis Systems, Chromis Feeding, Chromis Disease, Chromis Reproduction, Damsel Identification, Damsel Identification, Damsel Selection, Damsel Compatibility, Damsel Feeding, Damsel DiseaseDamsel Reproduction

Fish Aggression, Green Chromis        9/6/19
<Hey Eric>
Out of nowhere my Green Chromis has decided to relentlessly harass my Orangeback Fairy wrasse to the point that it was only coming out to eat.
<Does happen; unfortunately>
The fish were fine for 17 months so not sure what triggered it. I put a mirror on the side of the tank and the aggression has basically stopped with most of the fish just staring at themselves. How long should I
leave the mirror on? A few days, etc? Any other tips?
<I'd try taking the mirror away in a few days... see what happens. Yes to other... using two nets, catch the offending Chromis and place it in a floating colander (plastic) for a few days... IF the aggression continues, trade it out. Bob Fenner>

new Chromis not happy     8/21/12
<Eight megs of pix....?>
Hi there
I have been searching your website reading about experiences with Chromis.
We have just purchased 4 green Chromis for a 200 litre tank.  They are the only fish in the tank.   We have not had fish for several years, coral only.
They have been in the tank since Sunday afternoon, three are fine but one seems very scared, does not come out much from behind the rocks. I've noticed when the others go near it sometimes it's not impressed and gets a little cranky, it is the largest of the Chromis in the tank (but not by much as generally speaking they are all similar in size). It also has a white mark on its body, does not appear to be white spot, more a mark on its scales. It also seems to be getting darker in colour along the top of its body to about a third of the way down (compared to the others). When it moves its fins up and down I have also noticed it seems to be darker in colour where the fin joins the body (the other three seem to be white in that area).  So far I have put it down to stress as today (Tuesday) this fish has been out from the rocks more often.  It has had a little to eat, probably not as much as the others. We have checked our water quality and all seems to be fine.   I have added the product "Stress Guard" to the tank for the last two days.  Not sure whether to pull him out for fear the others will get sick (downside is we don't have a quarantine tank), or ride it out as it could be stress.  Any advice is greatly appreciated.
I am attaching two pics, the clearest one I have of the white mark on its body and also an image where you can see it seems quite dark on top, or another way of saying would be the scales are more noticeable because of the darker colouring (I should note this fish did not appear darker on top when we first put it in the tank).
Dinah Bryant
<Have seen this sort of trouble many times before... and it's archived on WWM. Read here: http://www.wetwebmedia.com/chromdisfaqs.htm
Bob Fenner>

Re: Reef Safe Butterfly Fish? Now Genicanthus Angelfish, And Now Chromis 2/4/09 Thank you James :) <You're welcome.> I will learn to correct my English from now onwards to assist you and your crew in your jobs :) <Will be much appreciated and often leads to faster responses.> Sometimes I get carried away because I am not used to typing properly like this. I usually use short forms and uncap my words. Hehe sorry for the trouble :) Ok, <i> will learn and read more about the fish <i>am currently interested in getting. If all else fails, I will probably get 2-3 Green Chromis...I like the colour and I heard they do well in groups. Well, since I am at it, is the Green Chromis very disease resistant? <Is a good hardy fish, tends to stay at the upper level of the tank. There are many much more colorful/interesting fish than the Chromis. Look at some of the gobies and blennies. A good reference book in this regard is the Reef Aquarium Fishes by Scott Michael. Is a nice paperback size book you can take with you to the LFS and is loaded with color photos.> I know they are hardy and not difficult to get them to eat, but in terms of disease resistance, are they very resistant? <Yes, they are and water quality and good nutrition goes a long way in preventing disease.> Sorry for all the questions :) I do apologise if my spelling/English is still a little bit wonky. <Is fine.> Thank you for reminding me that although my tank seems big enough to accommodate certain fishes, it might very well in fact not be big enough because of all the rocks displacing the actual water capacity, am I right to say that? <Is the swimming area. Your tank has an area of 864 square inches. A 90 gallon measuring 60" x 18" has an area of 1080 square inches giving you more area for the same size tank in gallons.> Thank you for your patience and you guys really deserve the best for creating this website to help people like me. <That thanks must go to Mr. Fenner who created this site. Bob may not answer all the mail, but I can assure you that each and every query is read by him.><<Ah yes. RMF>> Regards, Kai, who is trying to be a better groupie ;) <Thank you for the kind words. James (Salty Dog)>

Green Chromis hlth. I think, no useful data   8/27/08 I had 4 large Chromis in Quarantine. They looked ok upon QT. One died 3 days later of no apparent cause. The remaining three all are swimming, two are eating and look fine. One is swimming but doesn't appear eating. It has a small ulcer near the start of what I believe is the lateral line (top third of fish, behind the eye). I did some research and can't pinpoint whether it is LL or Hole in the Head disease. Any recommendations on a treatment if any? I did a water change after the first guy passed away. <... need info. re the size of your system, set-up, maintenance... Please read here: http://www.wetwebmedia.com/chromdisfaqs.htm and the linked files above. BobF>

Schooling Chromis - 9/14/05 Hello Robert and Gang (or Crew, whichever you prefer)! I have a 150 gallon tank and I was hoping to add a small group of Chromis viridis (5 fish) and Chromis cyaneus (3 fish). <Should be fine. I would maybe add the them all at once if your filtration can handle the load (likely if you aren't saturated fish wise) or I would add them in order you specified 5 Viridis and then 3-4 Cyaneus>  I've read on WWM, among other places, that these two species are more likely to form a shoal, or even school, when they feel threatened. <May shoal without bullying or predatory threats> I guess my question is: how aggressive of a fish will it take to threaten/frighten them into this behavior? <Likely a predator of some sort.> Would either of the damsel species Amblyglyphidodon aureus (Golden) or Dascyllus marginatus (Marginated) do the trick? <Not in my opinion but putting a fish or any animal under any amount of stress in a closed aquarium is just not proper in my opinion. Especially if just for aesthetics. Unfortunately, it happens all too often even at the top level. I don't mean to condescend or chastise, but I really have a hard time with actually accepting this type of configuration. We are all guilty of it at some level, though. Try to see if they will school before stress induced shoaling> Any other small, hardy fish come to mind? <For schooling I think your best bet is the Chromis. ~Paul> Appreciate you! -Trent 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.>

How many green Chromis - 6/2/05 I have a 30g saltwater tank with 20lbs of live rock and 2 false Perc clowns, 1 watchman goby, 14 hermit crabs, 3 snails, and 2 cleaner shrimp...was thinking of adding a small school or green Chromis...not too many because I also want to add a flame angel or royal Gramma in the future <Easy question for me. I might catch some flack but this is from my experience....I would not add a single Chromis or flame and go for the Gramma. The flame angel will get fairly large for such a small tank and sometimes will bully. The Chromis can be sensitive and would need to be added as an odd number grouping. Just a lot of stress if they are not real healthy. Quarantine is always necessary. The grammas stay relatively small and are quite hardy. Captive bred is usually best.> ...my question is what would be a good amount of green Chromis to add without over crowding my current tank so I can add at least one more if not 2 more in the future? <Go for the Gramma. Keep the fish small. Chromis tend to in-fight and if you must add Chromis then I would add 3-5 no more, no less. No flame in my experience. Gramma if you don't add the Chromis. A lot to think about but you will be glad as you will likely suffer less frustration from death and have room for the inhabitants. Thanks for being part of it all. ~Paul>

- Green Chromis - Hello,  <Hello.>  I currently have 2 green Chromis about 2.5 inches that pick on each other quite a bit, I would like to add 5 more to give me a small school but all I can find are small (1-1.5 inches) would the larger established ones kill the new smaller ones or would they school?  <I don't think so on both counts - Chromis are generally social fish and not nearly as aggressive as their Damsel relatives, so I think you add some more Chromis and in spite of their size things will go well. On the other hand, for reasons as yet undetermined, Chromis do not school so well in captivity - they form loose groups, but will not form tight schools.>  I have seen mixed size schools while diving but of course the living space was unlimited.  <And the predatorial pressure much higher... they are well aware of their environment and do not form these same schools in captivity.>  I do not want to buy more just to have them killed. Thanks Mike W. <Cheers, J -- > 

Chromis a good next choice?         Hello everyone. Hope you all had a nice Christmas/ Holiday. <So far...> I was wondering what some of your thoughts might be to me adding 2 or 3 smallish green Chromis to my 55 Ga. I currently have one 2 inch blue tang, one 2" yellow tang, a small blue devil damsel who minds her own, a 2" coral beauty and two false perculas. <Mmm, with growth your tank is pretty much full... and the blue devil may become more so with other damsels present... but if your system were about twice the size, these would be a good choice> I am definitely upgrading to a 120 in the next 6 months to a year. <Oh! Bingo! I'd wait till then to add them> I am running an Eheim 2215 and a CPR Bak Pak skimmer with 30 pounds of live rock which will soon be 50 to 60 lbs. Comments?? Too much bio-load an issue, I think I'm on the verge but is it possible? Ands also will the Chromis and my 1" damsel co-habitat? Much thanks as always.         -Heather <Bob Fenner>

Chromis mixing hello! <Hi,> I was wondering in a 150 gallon tank or a 125 gal. tank if you could mix 3 green Chromis and 3 blue Chromis together peacefully?  <Yes, they should get along peacefully.>  If so would they school together or school according to their species?  <It depends on the other tank mates.  If the Chromis are threatened they will school together as a defense mechanism (survival in numbers).  If not then they won't school at all.> Oh, and 1 more question, what's your favorite fish for fresh <Motoro Stingray> and saltwater? <Clown Trigger, or BlueLine Trigger I can't decide.> thanks again!! <No problem, MikeB> Chase

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>

Considering Chromis - 11/18/04 Mr. Fenner, <Paul in for Bob today!> I would like your input on these little guys. <Sure.> I have a 75 gallon with 120 pounds of LR and numerous softies. Currently I have a Percula, royal Gramma and a coral beauty. Tank has been up and running for over 6 years. Never wanted to get a big fish because of limited swimming space with so much LR. <Understand. A great idea regardless of tank size and swim room.> Thought about adding a few of these but were unsure of their temperament. <Well, actually, I preface my ramblings here with "this is purely my observations and opinions", but I find them to sometimes be quite aggressive even in a group of three. Also, they seem to have a bit of high mortality rating recently. Not sure if it is collection methods, poor acclimation at the wholesaler, poor fish stock in general or what. I have yet to get a stable batch in quite some time. We seem to keep the ones that live and try (emphasis on try) to add them together from different schools as they die off.> Will they get along with my other fish? <They should have little problems with your fish selection in my opinion.> Are they hardy? <Loaded question, but I would say they have been in the past but as I stated above, lately, the places I have seen, wholesaler/retailer outlets they have a high mortality rate currently.> How many would you add? <To your tank? I would say about 9-11 (odd numbers preferable) I was told they school and should add anywhere from 3 to 8. <Oh, you could easily make them the premiere display of your tank. They look awesome schooling, again though, they do seem to get a bit nippy and aggressive to each other in smaller schools. As a matter of fact, I would try adding like five at one time and then maybe another three a month later then add another three a few weeks after that. You will likely lose a few. Get them young, (Important, that they are on the small and healthy side) and from a quality store. Quarantine them if possible or see if the store can do it for you. (if possible) Acclimate them slowly to your tank, keep water quality high, and then wait for a month before adding another school. Just don't want to stress your bio filtration with too big of an addition at one time. Let me know your findings and if it works out send a pick of them schooling. Do use the internet as a tool and see what others are saying. Check forums and other articles in various books, too. Don't rely too much on one source. Hope this helps. Thanks for participating here at WetWebMedia. ~Paul> This is why I'm asking. Thank you Ken

Chromis Hello! I would like a few Chromis for my 55g tank. I really like the Blackbar Chromis (Chromis retrofasciata). I read in a few places that this fish, like other Chromis, are peaceful and do well in groups. However, I've seen in a few other places that they're just as aggressive as other damselfish. Do you know one way or the other? << I'll say good fish. >> I would hate to spend so much time and effort to find these fish, only to have them not get along in my tank (with each other or with the other fish). Other inhabitants are 1 fairy wrasse, 1 lawnmower blenny, 1 clown goby, 1 chalk bass. << I think you will be fine, and in general I think Chromis are great tank mates. >> Thanks! Kari <<  Blundell  >>

Catching A Cagy Chromis! Good Morning WWM, <Hi there! Scott F. here today!> I just set up a Quarantine tank after a bad case of Ich. I will quarantine all new arrivals. <Awesome! Another quarantine convert!> But my question is: I have only two fish left. A Black and white Percula Clown and a Blue Green Chromis. I was able to catch the Clownfish and put him the hospital tank, but I can not for the life of me catch the Chromis. (he never shows any signs of Ich looks and eats just fine) Is it possible to let the tank go fallow with just one fish in the tank. I don't think I will be able to catch him.  Any suggestions would be greatly appreciated. <Well, you asked...Really, a "fallow" tank means just that- fallow! No fish at all. This is the only way to carry out the process of interrupting the life cycle of the causative protozoa. I'd use any means possible to contain and capture this guy. Often times, fish like Chromis can be more easily captured at night, after the lights are out. You simply shine a flashlight on them, and use whatever fancy netting technique that you've developed to capture them. The only other option is to take advantage of their natural tendency to head into rocks when you try to net 'em. You simply remove the rock that the fish is hiding in, and place it in your treatment tank. Unfortunately, it's easier than it sounds...But definitely worth a try! Good luck! Regards, Scott F.>

Chromis viridis School Size I've had my new reef tank for about 4 weeks now. 72 gallons.  We added 3 Chromis after about a week.  2 were doing very well and the third seemed to be getting picked on a lot.  I read that a larger school might lead to less bullying, so we added 3 more last week.  They are acclimating fairly well, but that one timid guy is still hiding a lot.  He does come out to eat a little bit, but then goes back to hide.  Do you think he just needs a little more time or should we get a 7th fish to make for the odd-numbered school?  Instinct tells me that adding a single fish to this mix is not a good idea for the newcomer. Thanks in advance. <I concur with you concerns and would hold off on adding any more Chromis to this system. Bob Fenner>

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>

Cleaning substrate and fish compatibility Hi there. <Steve Allen tonight.> I have a 55 gallon fish only tank and about 100 pounds of live rock. I've been trying to figure out how to vacuum the substrate. Do you hook the hose on to your air pump or what? <No> I tried this but all that happened was it blew air into the water. <Not unexpected. There are a number of ways to vacuum substrate. The cheapest/simplest is with a gravel-cleaning siphon available at any pet store. Just vacuum with water changes. Personally, I use a Magnum 350 canister filter with the micron filter insert. The water goes back into the tank, so I can vacuum to my heart's content without fear of taking out too much water. There are also motorized gravel vacs you can buy that are hand-held and self-contained, but they seem rather wimpy and flimsy to me.> Currently I have 5 fish in my aquarium, 1 Scopas tang <Needs at least a 75G tank to thrive.> ,1 false Percula, 1 orange lined Chromis (he's lost his orange line and is turning brown) <Could be a sign of stress, malnutrition or disease.><<Or just this species developmental change. RMF>> a sixline wrasse and a dwarf Hawkfish. I was wondering what else to put in with these guys. <Nothing at this point. You need to figure out what, if anything, is wrong with your Chromis. Any other fish that go in there should not be ones that can/will outgrow the tank.> I was planning on a mated pair of coral beauties <almost impossible to achieve in captivity> ,a valentini puffer <too big> another false Percula <you might be able to get it to pair up with the one you have. Read the clownfish FAQs about this. Do not add some other species of clown.> and a mimic eibli surgeon <I'm guessing you mean  Acanthurus  pyroferus, which grows way too big for your tank and will not get along with your Scopas.>  are these good choices? <Maybe the clown, and/or a single Coral Beauty.> thanks a lot. <Hope this helps.> 

Chromis color change The orange lined Chromis is supposed to lose his color when he's juvenile he's blue with a orange stripe but is his adult form he's brown with a white tail... just thought I'd let you know <Yep. Thank you. Bob Fenner>

Chromis Quandary Hi Crew, <Hey there, Scott F. here with you tonight.> Continued praise for your excellent work.  A few questions for you: <Alright...ready!> I purchased 3 green Chromis and 1 Ocellaris clownfish from my LFS  about 4 weeks ago and placed them in a 20 gal QT tank. <Excellent procedure.  Glad to hear that!> After 2 weeks, I noticed that one of the Chromis was constantly harassing the other two, so I removed it from the 20 gal QT and placed it in a 12 gal QT (by itself). Everything appeared to be OK until one of the 2 Chromis (in the 20 gal QT) died about 2 wks. later, from what seemed to be tail rot.  The 2nd Chromis (in the 20 gal QT) also showed signs of tail rot but the clown fish seemed fine.  I treated the fish in the 20 gal QT with Furanace and the 2nd Chromis now seems to be OK and its tail is growing back.  The aggressive Chromis in the 12 gal QT did not show any signs of tail rot and was not treated. Questions: 1) How much longer do I need to quarantine these fish (i.e., 2 fish in 20 gal QT and 1 fish in 12 gal QT) before I place into my 72 gal display tank? <If it were me (and I have done this before), I would start the clock again.  Meaning another 3 weeks in the QT for these guys just to make sure that everyone is healthy.  I know it's not fun, but it's the correct way to do it, IMO.> 2) If I do not need to quarantine the Chromis in the 12 gal QT for an additional period of time, should I put it in the display tank or will it become territorial towards other fish once I add them to the display tank.  (Note: the display tank does not currently have any fish).  Or should I return the aggressive Chromis to the LFS and try to exchange it? <Great insight and interesting question.  As you know, these fish can occasionally become rather territorial, particularly if they are the first fish in the new tank.  I would either add this fish when you add the other fish (i.e. three weeks as discussed above), or exchange it for a more docile specimen.  However, you will still have to quarantine, of course.  And, there is no guarantee that the fish that was docile at the LFS will remain docile in your tank!> Also, I would like to move into phase 2 of my stocking plan and buy the following live stock (for quarantine): -3 Peppermint Shrimp -2 Cleaner Shrimp -1 Blood Fire Shrimp -3 Green Chromis -1 Yellow Tang -1 Watchman Goby -1 Algae Blenny <Very nice choices assuming that your tank is large enough to accommodate all of your animals.> Questions: 1) If I move the two fish currently in the 20 gal into the 12 gal tank (with or without the aggressive Chromis), can I then use the 20 gal QT for the new live stock (after performing a 100% water change in the 20 gal QT)? <Sure, it will, after all, still be a quarantine tank and you can treat as necessary in that tank.  Of course, do be mindful that the inverts do not tolerate medication if you have to medicate your fishes while in quarantine.  In other words, I wouldn't quarantine inverts and fish together.> 2) Is this too much live stock to quarantine in a 20 gal tank at the same time? <I would say that is pushing it a bit.  Go slowly and get a couple of fishes at one time.  The tang, in particular, need a significant amount of space and good water quality.  Be mindful of this.> 3) Will the new live stock be compatible in the 20 gal QT during a 3-4 wks quarantine period? <With the exception of the inverts and perhaps, the tang, you could probably combine these animals without incident.  Keep an eye out on those Chromis.> 4) After performing a 100% water change, will the 20 gal QT be safe for invertebrates (after the prior use of Furanace in the tank)? <Yes, but I would recommend running a Polyfilter and/or activated carbon for a few days prior to adding the inverts just to make sure that you get any residual medication out of the system.> Thanks for your help, Ade <My pleasure Ade.  BTW.. if you have a moment, check out Conscientious Aquarist, Issue 2, online now on WWM homepage. Regards, Scott F.>

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>

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

Chromis (1-13-03) Do blue Chromis keep their intense color when they grow up? <If fed the right foods and kept in good conditions they should hold their color just fine.> or will they get drab the way damsels do?  how large will they get? <Well we just had some traded in at the store that are about 4 inches long and I suspect they are fully grown.  Cody> thanks!  Beth

Chronic Chromis.. >Hi Crew, >>Greetings.  Marina today. >I have a question regarding the behavior of my two blue/green Chromis.  They used to both swim around the tank openly.  After having them for several months, the larger one began chasing the smaller one into hiding anytime he came out.  This went on for several months.   >>Not terribly unusual for certain fish when housed in pairs. >Now for the last couple of months the bigger one has been hiding all the time behind the overflow box with the smaller one.  They both come out to eat but spend the rest of their time hiding. My tank is a 55 gallon and I only have two other fish (Royal Gramma and Pink Skunk Clownfish) neither of which is aggressive toward the Chromis.   >>Actually, I have a good friend in Loma Linda who houses a Maroon clown (talk about a FAT piece of meat that fish is!) and a lawnmower blenny with two green Chromis and they do the exact same thing.  It's my opinion that there is, indeed, aggression in the form of body language that essentially screams to the fish "STAY OUTTA MY WAY!" >The other strange thing I've noticed recently is that as soon as the lights go out at night, the larger Chromis comes out and starts swimming rapidly back and forth along the length of the tank.   >>That is interesting, if it were a horse I'd say that's when he feels comfortable enough to get the exercise/burning off of energy he needs. >This goes on for at least a couple hours until I go to bed.  The rest of the lights in the room are off or very dim.  This behavior must likely be indicative of something but I can't determine what.  I hope that you can give me an idea of what is going on?  I enjoyed watching four fish swim around the tank but it pretty much looks now as if I only have two fish. Thanks for your insight! Bryan Mullennix >>Well, I can't offer much more in the way of insight, nor a way to reverse this state of affairs. But I could possibly offer some solutions.  You're limited with the number of fish you can have in a 55 gallon tank, so consider removing the Chromis and clown, and getting credit on them.  You could easily house a dwarf angel in there (do be selective of species, I'm thinking along C. argi, C. loricula/loriculus lines), sixline wrasse, or fairy/flasher wrasse, very small gobies, such as neon and clown gobies.  All of these would offer movement, though not schooling, and color, withOUT getting too large for the tank.  Marina

The Chromis Were the Culprits? II >Great, thanks. (By the way, I didn't receive a response from you the first time I sent my message, and I value your opinion so much that I couldn't rest until I heard back from you about my concerns, so I resent the message.  Hence the "deja vu".) >>You're very welcome, Barb.  Now I understand, though I'm puzzled that my response didn't come through.. I hope others didn't get lost in electron-ic limbo! >Believe it or not, a week from tomorrow marks the 30 day quarantine point (after my Coral Beauty died) for the Chromis. They're doing well.   Thanks, again.  Barb >>Excellent, I think you, and they, are ready!  Marina
The Chromis Were the Culprits? III
>Hi, Marina. (I promise one day to stop pestering you.) >>Hello Barb, it's all in how ya look at it, right? >You made me wise in the past to white, stringy feces as an indicator of an internal infection. If it starts out long, white, and thin and then develops into the orange coloration that I would expect from ingestion of Formula One flake, is that okay, or is it a sign of trouble brewing? >>I would watch them, though the flake can stain the feces.  Just keep an eye, and I *know* you're ready with the q/t! >Two of the 6 blue green Chromis (research revealed to me that, with the absence of a black spot at the base of their pectoral fin, they're blue green Chromis, not green) eliminate in that manner from time to time -- and have for about a week or so. No other problems physically or behaviorally. Call me overcautious, but I just want to be sure I'm bringing only healthy fish into my main tank this weekend. >>Ok, "over-cautious", I would watch them *before* I added them.  At this point, what's a few more days, right?  Sorry I didn't get back to you during or before the weekend, I just haven't been up to snuff the past few days.  Hopefully, either their elimination has improved, or you've kept them in q/t if suspicious. >Also, does one gender of Chromis have longer tail fins? Two of mine have longer forked tails than the other four fish. >>I'm not entirely positive of sexual dimorphism, but it's not uncommon in damsels and other related fishes. >Imagine splitting a piece of yarn in two and twisting each end between your thumb and index finger. The ends look like that. I noticed that tail fin characteristic on my smallest Chromis several weeks ago, but, since nothing else seemed wrong with it, I didn't panic. >>I would tend to think it's either a sign of maturity (possibly sexual) or health. >The second fish displayed it a week or so ago. Could it be a sign of maturity, gender difference, or illness? >>I've never known what we call "trailers" or "streamers" to be a sign of illness.  Quite the opposite. >All other fins look perfect (nothing rotting).  Thanks in advance, once again, my new friend. Barb >>Sounds as though everything's going well (other than the fact I haven't gotten back to you till today), and your fish are likely doing very well if developing streamer extensions on, I'm assuming, the caudal and other unpaired fins.  Glad it's going well.  Marina
The Chromis Were the Culprits? IV
>Hope you're feeling better, Marina. We had a bout of the "crud", too. >>Oh my.. mine wasn't exactly "THE" crud, probably a weak bout with a cold more likely.  No fever or sniffles, just a general ill feeling.  All better now, yes? >I took the plunge and transferred the fish from the QT to the main tank on Sunday and everyone seems fine... eating, swimming/playing, and trying to make friends with the other fish (the yellow-tailed blue damsel chases them away from his favorite area, but the yellow tang likes to hang out with them). I think it was the right thing to do... that QT even depressed ME. I'll keep you posted.   Barb >>Please do, what a holiday those little fishes are having NOW!  Hhmm.. do I feel a bout of Christmas prose coming on?  (I grin a devilish grin - here it comes!)
-The Chromis Culprits' Christmas-
The little Chromis culprits, twice three Set in their new digs Swim about with glee No, not too far From thine Christmas tree (Assuming, I did That you do use A Christmas tree Not Menorah Or other to choose) They frolic and play In their fishy way And swish their fins Splashing this way and that As though to say "Hooray! We're Free! O! Yes, Hooray!"   Yes, cheese it was But the best I can do On the fly Off the cuff As it were Would, could you? Best holiday wishes Barb!  Marina

Cryptic Chromis? Hey WWM crew, <Hey there! Scott F. with you!>    I just got my first fish, two green Chromis  to start off my tank. When I got them in the tank, I only saw 1 Chromis all the way at the bottom of the tank by some rock, but he isn't really hidden, and I think he is doing well. But I still haven't seen the other 1. He was the first to enter the tank, so I couldn't see were he went cuz I was worrying about the other.      I still cant find him. I think he might be in some of my rock. Should I be worried. Thanks <Well, I'm taking a guess here. It's hard to know where the missing fish is and why he's hiding. Many times, fishes will hide shortly after introduction to a new tank. They will usually remain hidden until they are comfortable and ready to be out in the open. Alternatively, fishes that are injured, shocked, or otherwise uncomfortable will often seek refuge in the rocks to recover...or die (gulp)...Just needed to fill you in on both possibilities here! I would not be overly concerned unless a week or so goes by without seeing the fishes. Do observe the tank carefully, and monitor water conditions to make sure that everything is A-OK...Keep your fingers crossed, and hopefully, all will be well! Regards, Scott F.>

New Stock - 11/20/03 I've now set up my new 150 gallon marine system- upgrade from a long run 75g- I've cycled and everything- ammonia 0, nitrite 0, nitrates are embarrassingly high 60+- but with a college bio/chem staff, we know its from our source water, so I'm not sure water changes would really help- what is a good water treatment product? <de-ionized filtered water ideally. Else Polyfilters and natural nitrate reduction from a deep sand bed> I was also wondering, with the following tank mates, would it be wiser to buy 3 or 5 blue-green Chromis? <they'd be much better off with 5 minimum to school> I'd rather do the healthiest thing for all 1 yellow tang 3"</DIV> 1 Hippo tang 4"</DIV> 1 Maroon Clown 3"</DIV> 1 3 stripe damsel  1"</DIV> 1 Yellow tail damsel 1"</DIV> 1 Blue damsel 1" </DIV> we may add a goby or two in January. I'm definitely going for a light bioload to help with nitrates.  I just bought over 2 liters of copepods/amphipods, and am going to let them populate in the 50 gallon 'fuge before trying any live food fishes- thanks, mike <skip the Chromis here Mike... your other fishes are too active and aggressive for the peaceful Chromis damsels. Best regards, Anthony>

First Fish (11-17-03) Thanks. <No problem.> I have one more question. Would a Green Chromis be good in my tank if I put 2 of them in or no.<The Chromis should be fine but I would put 3 as odd numbers usually help distribute aggression.  On the other hand you also don't have a lot of room to work with.  You can find some more info at our site www.wetwebmedia.com.  Cody>
First Fish (11-21-03)
Hello again, <Howdy> Sorry for all the questions. <No problem!> But would 1 Green Chromis be fine instead of 3 or do I need them in groups. This will be my final first fish question. If this won't work, would a yellowtail damsel be fine. Just 1 though.<You should be fine either way, just make sure the Chromis is eating well and active before you take him home.> Thanks

Crazy Chromis! We have a 100 gallon tank that recently developed a horrible algae.  The closest we can figure is it's a brown diatom (?) algae. <Usually eradicated by using RO/DI as source water...Silicates tend to cause this problem> We have "vacuumed" the algae off of the rocks and done about a 25 gallon water change at each vacuuming.  We got another 30 gallon tank for the Chromis because they turned white, hovered straight up in a corner, and acted as if they were having seizures. <That's not good...Lots of possible causes, ranging from some water chemistry issues to an infection of some sort...Do a little research on this...> Our tank finally cleared, with little algae left in the tank, so we took everything "back home."  Much to our dismay, within six hours the Chromis were back in their corners, acting spastic.  Why are they doing this?  They are the neatest fish, so calming to the tank, (and to me,) I hate to see them this way.  This is our first saltwater fish tank, and we are definitely learning a bunch.  Any thing you can tell us would be greatly appreciated.  Thanks in advance, Anne   <Well, Anne- I'm thinking that you may have measurable ammonia or nitrite levels in the water...Do check this out, and take appropriate actions (water changes, etc.) to correct.. Regards, Scott F.>

Keeping Chromis Happy Morning! <Hi there!> Hope you all are doing well. <And the same to you! Scott F. here today!> Reason for "writing" today is.... I have purchased 3 blue-green Chromis and talk about beautiful coloring!  Wow! <They are cool fish, huh?>   My question is this: How can you tell the males from the females? <Hmm... I am not aware of any external sex differences. Other damselfish species can be sexed by fin shape and coloration, but I have not heard this with this species...> And, if I do have both sexes, what are the chances of them actually successfully breeding in captivity?  I have heard that they are difficult breeders and that it is not common outside of their natural habitat...? <I have heard a few accounts of their spawning in captivity, but I have not heard about the larvae being reared...> Also, I was wondering, since they are peaceful, to be able to keep them in a 30 gallon tank with 2 yellow erectus seahorses? <While they are peaceful, they can be rather active, which might intimidate the seahorses during feeding. I'd pass on this combo, myself.> There is plenty of space for all of them and as I have found out... LOL. They (Chromis) are DEFINITELY hearty eaters!  I have been mixing live brine shrimp with frozen and also been adding a few flakes for them as well, they seem to do well with the mix and I am finding that there are still plenty of live brine shrimp swimming around to feed the seahorses as well.  Am I just asking for disaster by trying to keep these two beautiful species in the same tank? <Well, I don't think it's disaster in the making, but I think that you should observe carefully to make sure that the seahorses are getting their food...Also, as you mentioned- they are both pretty spectacular species, so why not keep each in its own tank?> Thanks for your time and attention.  Hope your day is a wonderful one! Jena <Thanks for the kind words, Jena! I hope you continue to enjoy these beautiful fish! Good luck! Regards, Scott F>

-Blue Chromis massacre!- Hi Again, I thank you for your time and web site, it helps me so much. I have a maintenance company in Bakersfield, Ca. In my home I have  a  80 gal, 40 gal and a 10 gal tank used as a holding tank for new fish for my customers. Three weeks ago I bought 10 blue Chromis and within one day all had died with red blotches on them and some with Popeye. <Ouch, was the system tested before fish addition and once the problem started?> So I started moving the rest of the fish away from them and treated the tanks with MelaFix, to no avail. Within  three days all fish were dead. since them I have done a 80 % water change, and put each tank on my LifeGuard mechanical system for about 45 minutes each, it also has a U.V. in it. <This won't accomplish much> I waited three more days and entered 3 two striped damsels, in each tank. day two the 10 gal tank as no fish left, the 40 as 1 fish left and the 80 as two fish left.. In each tank has little live rock in them and the tanks have cycled two month ago. <For them to still be cycled, they had to have a constant ammonia source (like fish) in there ever since the cycle. If there was no detectable ammonia or nitrite, the pH was fine, and there was no blatant horrible shipping stressor or other catastrophe, you got bad fish.> All levels were normal and still are. <Well, if this is the case, then the fish you bought were likely doomed from the get-go. Again, you may want to test your salinity, temp, pH, ammonia, nitrite and make sure that no possible contaminants could have entered the water.> what is one to do ? <Large water change, PolyFilter (in case of chemical contamination), and potentially letting it go fallow (no fish) for a month to eliminate the chance of reoccurring disease. I hope this helps! -Kevin> Le Roy @ Advanced Aquascaping

- Blue/Green Chromis - We recently restarted our 65 gallon tank (after some much needed repairs) and decided on 4 blue/green Chromis as our starter fish. All 4 were bought at the same time at the same store. Within a day, the smallest fish developed a red bruise like spot just in front of his tail. At first we thought it was a small bite but within hours it turned into what looked like some sort of internal rupture. We tested for water quality and everything looked good. He was next to dead the next morning so we scooped him out. We replaced him with another b/g Chromis and the next couple of weeks went along without incident until this past Tuesday the next smallest fish developed the same spot. We have been testing regularly and doing all the necessary water changes and everything is fine. <If you are cycling the tank with these fish, then you shouldn't be changing water until the nitrogen cycle is complete. Changing the water will only delay the completion of the cycle.> He lasted a couple of days but we scooped him out this morning. These fish show no other signs of distress and eat and swim around normally until the very end when they have increased respiration and go into 'hiding' mode. <Hopefully they have many places to hide, yes?> Any ideas as to what this may be? <Low man on the totem pole perhaps... live stock compromised before you got a hold of it... toxic water conditions... there are many possibilities.> We are reluctant to start thinking of buying any other fish until this can be resolved. <Considering that you are using these fish as 'starters' you've got to expect some attrition. Do keep an eye on ammonia and nitrite as these are toxic to the fish.> Cathy <Cheers, J -- >

Stocking Questions (9-9-03) I have a 56 gallon Perfecto tank... roughly 20" high, 25" across, 15" deep.  My current inhabitants are as follows ( 1) 2" Maroon Clownfish (1) 3" Yellow Eyed Kole Tang (1) 11/2" Purple Pseudochromis (1) 2" Bicolor Pygmy Angel (3) Turbo Snails (2) Peppermint Shrimp Would it be ok to include 3-4 Blue Chromis in this tank?<The maroon clown and the tang will both need a bigger tank in the near future.  I would not add the Chromis until you get a bigger tank. Cody> Thanks for your advice!

Sending Chromis To School Bob:  (Or whomever :o) <Scott F. the "Whomever" tonight! Glad to be of service!> With regards to the Chromis family such as the blue-green: I would like to have a school of these in a 55g FOWLR tank - is this possible?  If so, what is the maximum population you would recommend (no other fish). Thanks, David <A monospecific (one species) display of Chromis would be hot! I'm stoked hearing about that! Chromis atripectoralis, the "Black Axil Chromis" can reach about 4 inches, and the "Blue Chromis", Chromis viridis, can hit over 3 inches, too. I'd figure that you could get away with about 5-6 individuals in a 55 gallon tank, but this might be pushing it a bit. If you leave a lot of room for them to swim (in other words, keep your rockwork low), they will school and behave in a much more natural fashion. Just keep the water quality high and the feedings frequent, and you'll be rewarded with a beautiful display! Enjoy! Regards, Scott F>

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