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FAQs about Odonus niger Triggerfish Systems

Related FAQs: Odonus 1, Odonus 2, & FAQs on: Odonus Identification, Odonus Behavior, Odonus Compatibility, Odonus Selection, Odonus Feeding, Odonus Disease, Odonus Reproduction, & Triggerfishes in General, Triggerfish: Identification, Selection, Selection 2, Compatibility, Behavior, Systems, Feeding, Diseases, Triggerfish Health 2Reproduction,

Related Articles: Odonus niger, Triggerfish, Balistoides Species, Red Sea Triggerfishes

Triggerfishes for  Marine Aquariums
Diversity, Selection & Care
New eBook on Amazon: Available here
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by Robert (Bob) Fenner

Niger Triggerfish and His Home  7/23/10
Well here is the deal, my 4 inch Niger Triggerfish has been in a 75 gallon tank with a 4 inch Tomato Clown fish for a little over a year now, and since he (assuming that the fish is a he) was placed in the tank he has been claiming the same aquarium decoration as his home. In a few weeks I am planning on moving them into a larger 100 gallon tank and am wondering if I can move the Trigger without bringing this decoration/home with him. I am going with a different look in the bigger tank, and this decoration will clash.
Will this cause any problems or put stress on the fish, or will he easily adapt to the new environment?
<Can't tell... it may. I'd incorporate (hide) the decor item w/in some of the new hard structure (rock) of/in the new system>
There will be around 70 pounds of live rock with crevasses and caves in the new environment. Thanks for your help.
<Welcome. Bob Fenner>

Stocklist Question (Damsel Mix and Large Trigger in a 56g? '¦nope) -- 12/27/09
Hi Guys,
<<Hello Chris>>
I've been reading your site for a while now and can't find the answers to what I'm asking here. To start I've got a 56 gallon (30x18x24) that is fully cycled with 40 pounds of LR, pH 8.4, no ammonia/nitrite, nitrate 5-10 depending on time since last water change. I've currently got a small (2") Niger trigger and a 1" yellow tail blue damsel, a few hermits a turbo snail and some Nassarius. My first question is can I get a large coral banded shrimp while the trigger is small and have any chance that it will leave the shrimp alone?
<<Probably, for now'¦although a large Coral banded Shrimp may well pose a hazard to that 1' Damsel'¦and as the Trigger grows, it will pose a hazard to 'all' your shrimp/crabs. And speaking of that Trigger growing'¦I consider your tank to be exceedingly small in the long term for this large deep-bodied fish, that can attain 18' in length in the wild>>
Secondly, for additional fish I was thinking about a maroon clown and more damsels. I like the Beau Gregory, the YTBD I wouldn't mind having more of, and the others that have caught my eye are the Velvet and "Flame tail" (aqua with red/orange tail). I'm trying to stay coral safe.
<<I think a mix of Damsels (to include the Clownfish), especially in this volume, will only lead to problems my friend. If not just killed outright, the constant harassment from more aggressive individuals will lead to the other's demise until only one specimen remains (and crowding the Trigger only make matters worse where it is concerned). I truly think you need to re-research/re-think your stocking plan>>
I know the Niger can/probably will eat a lot of the clean up crew, but I'd like to have some mushrooms, green star polyps, zoos, and maybe some others, but I'm not planning on making the tank into an "out and out" reef.
<<Hmm'¦live rock, fish, crustaceans, and sessile inverts'¦how's this not going to be a reef tank [grin]?>>
Do you think this combination has any chance of working out well?
<<'Working out well?' No, I don't think it will>>
I know damsels can get mean,
<<Indeed'¦'are' mean>>
which is why I'm wondering if a mostly damsel tank can work.
<<Generally, this just does not work out in a system this size'¦even with those so-called 'gentle' Damsel species (e.g. - Blue/Green Chromis)>>
They interest me because they pack a lot of color and personality into a small space.
<<Ah, we are much in agreement on this'¦but I think you must be more realistic in your stocking plan>>
Thank you in advance for your help.
<<Happy to share'¦>>
I'll continue reading you're articles.
<<Yes, please do'¦ I am compelled to again assert that this tank is too small for the Trigger'¦and indeed the Maroon Clownfish. Perhaps a few of one, and maybe even two, social species of small Cardinalfishes would appeal to you. These would be a much better selection for your tank than that which you have now or are contemplating adding'¦in my opinion>>
Re: Stocklist Question (Damsel Mix and Large Trigger in a 56g? '¦nope) -- 12/28/09
<<Hiya Chris>>
I'm going to be going larger (probably a 180 "full aggressive fowlr") down the road.
<<Ah, good>>
That said the trigger is 100% on the "relocate" list.
Would cardinals as you have suggested work out okay with the trigger until he needs moved?
<<Considering the diminutive size of this Niger Trigger it should be fine for now>>
Thanks again,
<<Always welcome'¦ EricR>>

Triggers and water parameters - 2/11/03 Hello Crew! I swear I'll stop pestering you folks one of theses days, but until then.....?
<No worries. Paul in the seat and ready for lift off.....what can I do for you?>
  If you wouldn't mind indulging me....I have a Niger Trigger in a 55 gal waiting for the last phase of cycling in my 125 gal before I relocate him there. <Good> This Trigger has the curious, and I'll admit, humorous habit of constantly moving substrate from the back of the tank with his mouth and then gracefully...politely, even, depositing it all over my/his live rock and  the front of the tank.  It never ends!  While I know Triggers do this sometimes, my question is, could this disturbance of the substrate explain my fluctuating nitrite levels from 0 to .25.
<Possibly smothering the aerobic bacteria>
 I also pose this question because this fellow has created peaks and valleys all over the tank and I mean deep ones. too....four inches in spots.  I seem to recall that you mention (don't recall exactly where) that this is ok if it is only 1/2 inch deep or so or am I mistaken?
<I believe the 1/2 inch or so was regarding the depth of the sand bed in general if not maintaining a deep sand bed. If you want a deep sand bed then it would more than likely need to be over 4 inches throughout the tank. The high nitrite issue could also be improper filtration methods to handle the breakdown of ammonia to nitrite to nitrate processes. What type of filtration is being used? Live rock in this holding/quarantine tank? Is the sand live? Sponge filter or sump etc.? Maybe adding one of the additional filtration methods would be a good idea depending or not what this tank is used for. Not enough specifics here to really help you on that aspect. Sounds like your trigger is having fun though. =). Paul a little tired, as it is late and have a cold to boot. I may be missing something here...... > Again, I thank you and am so grateful for your words of wisdom. <Hardly words of wisdom. Was the 55 gal used for other animals or are there other animals being housed with the trigger? Were the nitrites always high in this tank before the trigger addition? Look in these areas. Ask yourself the "before" and "after" and see what you come up with. In the meantime I would change the water and get the nitrites down.> Michael  
<Thanks Michael. Hope I inspired some thought and was able to lend an assist. Paul - going to bed.>

Big Nigers How big do Niger triggerfish get really? I've read they get 12 inches but also read they get 18 inches. I was am planning on getting one for my 55 gallon aquarium which is 4 feet long and also how long could I keep one in my aquarium before upgrading ***Hello, While Niger triggers are among the very best of marine aquarium fish, they are not appropriate for a smaller tank. Anything under 180 gallons will not house this fish long term, regardless of what you may read in a book. Yes, they reach 18" or so in the wild, this includes the fin trailers. In captivity, 12 to 14" is likely, meaning that it's MUCH too large to keep in a 55 gallon long term. The other item of note about this species is that unlike some triggers, they grow FAST! So if you put a 3" specimen in a 55 gallon tank, it's likely you'd have to upgrade the tank or sell the trigger at around the 18 month mark. You also don't say what else you have in the tank, which could be a factor as well. A much better choice for you given the tank size would be a trigger of the Rhinecanthus genus. This includes the Huma Huma trigger (R. aculeatus) and the Rectangulus trigger, (R. Rectangulus). They grow slowly, so you could keep a Huma Huma in a 55 gallon tank for years if you start with a 2 or 3" individual. Again, with the caveat that he may not be an appropriate tankmate for certain fish, and should certainly be the smallest fish in the tank regardless. They do well most of the time if added last as the smallest fish. Good luck. Jim***

Niger Trigger I have a 135 gallon tank in the works.  
<Oooo lovely>
 I have had a 55 set up for about 6 months now. I've been planning on what fish to stock the 135 with, I was thinking a Niger trigger a Humu Humu trigger and a harlequin tusk?
<I really would like to caution you about the two triggers. Let me be honest and tell you that I know people who have them together with good results and I know people who have them together with bad results. But triggers are aggressive and can hurt each other. They are also very competitive and might over compete with other fish for food.> are all these fish appropriate for my 135? Will they out grow it? Also would a Niger trigger be ok in my 55 for about 2 months?
<Yes it should be just fine for a short period of time. But these fish as they grow need the mental stimulation of a larger tank. The ability to swim back and forth.>
The one I'm looking at is about 3 inches right now. His tank mates would be a Scopas tang and a Percula clown fish. <Let me know what you decide Sharon, keep us up-to-date on your setups. MacL> thanks a lot Sharon

Niger Triggerfishes Hello,         What are my chances of success of keeping two Nigers in a 65 gallon? I have a 3" one in the tank now and would like to add a 6" one, will the size difference diffuse the aggression on the part of the original trigger? Thank you <Short answer: not good. This size tank is ultimately not large enough for one specimen. Would you like to be confined to a room about the size of your kitchen with a grizzly bear? Even if you both started off young/small? Me neither. Bob Fenner>

Niger in a 55 Hello All, <<Hello One. Marina here.>> Today I purchased a Niger. I have a 55gal w/one snowflake eel (10" long), one yellow tang (3" long), one Valentini puffer (3" long) one cleaner wrasse (2 1/2" long I know he's a short term fish. Thought I had ich)... <<Wait a minute, you're saying that you purchased this fish KNOWING that it wouldn't survive long-term??? That equals bad Karma, baby. BTW, one of the WORST choices for controlling ich, ESPECIALLY with such small fishes!>> ...one false percula (2 1/2" long) and one Anthias (2 1/2" long). <<Jeez, you've hit your limit a while ago, there.>> Niger is in qt tank for now. <<Ok.>> My intent is to move the tang, trigger and maybe the eel in a year to a 120gal. <<Why wait a year? These fishes, numbers, should be in such a tank NOW.>> My question, would they all be happy and play nicely in the 55 until the 120 is up and cycled? <<You are VERY overstocked as it is. This is, in my opinion (considering the habits of the fishes you've listed) cruel. I'm sorry to be so blunt about it, but there it is.>> In the 55, I have 60lbs or more of live rock, I do a 3-5 gal water change every other week and a 25% water change every month and a haft or two. <<That doesn't do enough, in my opinion, to keep water quality up, and it sure as heck doesn't give them the swimming space they need. Especially the tang and Anthias.>> No algae blooms, water test are in range and top off with R/O. <<As ever, I ask, "What is 'in range'?" Tells me nothing, and I'll remind you/all that this is ONLY the stuff hobbyists can test for, does not come close to telling the whole story, my friend.>> If you suggest not keeping all together, I do have a 30 gal reef, but if I can get away with it, I'd rather not move anyone out.. Thanks all Brenda <<The 30 is a nano, and outside of the clown no other fish would really be suitable for such a small system (I would have moved it there a long time ago.. unless THAT's already overstocked with vertebrate life). I hate to say it, but you've got to decide what's more important - having these fish now (all of which are quite readily available, so I don't see the point), or providing them the best you can in/for the long term.  I also hate to say this, but it really seems to me that you're not exactly taking into consideration the fishes' psychological health/welfare. Water changes are great, but the frequency in such an overstocked system leaves something to be desired, as well as the amount changed.  The tang alone is problematic in a 55, could do alright for a few months to a year as long as growth is stunted/delayed. But adding in all those other fishes.. whew.. Alright, as things stand, I really DON'T think they'll do well for more than a few months given husbandry, tank-mates, housing. Get the 120 NOW, or give up some fishes. Marina>>

How About Adding "Volume on the Cheap"? Niger in a 55 Take Two Hello again, <<Hi Brenda.>> Bluntness is not a form of cruelty, when it comes as a wake-up call to a potential disaster. Reason for delay in 120, basement is under construction. Really don't want drywall dust getting into water even with a cloth cover. <<Ah.. Can't blame you on that.>> The 55 housed the clown, Anthias and bicolor for a year. Puff came along, to help with a mantis problem in 30. Eel was a hitchhiker in large rock (lucky me). <<Holy Canoli.. you got a snowflake as a hitchhiker? Jeez, eyeah (lucky you).>> Bicolor mover to 30. Puff stayed in 30 until 3 months ago. Tang was given by Army friend shipped over. <<Ah, yes.>> Had him in QT tank moved him in 55 came down with black dots got cleaner for him. He cleaned him up good. I guess when I said "I thought I had ich", I should have finished and said worms. I would love to keep the cleaner, but everything I've heard and read, they don't have a long life expectancy. <<They do, but not in most captive situations. They require large, and large numbers of, fishes upon which to perform their duties. There are anecdotal stories of folks getting them to feed on other foodstuffs, but I have yet to hear of one living in a situation such as yours long term. This is why WWM, as a whole/group is so against the sale and purchase of these animals (for the most part).>> Any suggestion would help. <<Here it is: Are you able to add water VOLUME to any/all of these systems via additional sump or similar? Rubbermaid or similar plastic tubs can add 20-30 gallons for a small price, and all that would *really* be needed beyond that is some tubing and pump. If you could add macroalgae to them, even better, but it's going to allow you and the fishes a much larger buffer in all situations. Heck, these things can even actually act as tanks.>> Today was a big move day for some. Niger will remain in QT for a month or so. Clown move to reef. Have a small 12 gal nano reef; Anthias is there until I can think of something. Didn't move him to 30 because of cleaner and peppermint shrimp afraid he would nip. 55 has puff, tang and wrasse oh yes and eel. <<Whew!>> Mention water, cause I was hoping you might say "keep water quality good and you might get by for a year". <<Keeping water quality up can definitely help, but I can't tell you with a straight face that all these animals could get on for a whole year this way. Can you trade in some fishes right now? The cleaner, at least?>> Not this case. Failed to mention QT tank is 30 as well. If any of these moves don't seem reasonable, please suggest something.....I know get the 120 going........B- <<Heh, yeah. But, in the meantime if you could thin the numbers in each situation, and add water volume, then you could squeak by. On water changes alone... I am hesitant (but that doesn't mean add volume don't do more water changes). Additional chemical filtration (something not yet mentioned) is sometimes helpful, but can quickly become expensive. Again, reconsider the numbers/purchases here. You have a lot of trouble even if things do go smoothly, a crap shoot. And that's my best advice. Marina>>

Niger Trigger   1/10/06 (I am resending the below message just in case it was never received. My virus scanner is on the blink and causing all sorts of trouble.)
<Thank you for this. We have webmail issues off/on as well> Crew,     As always thanks in advance. I am having a problem with my Niger trigger. First off the long and not so short; 55 gal. <... too small a volume for this species.> FOWLR, pH 8.3, temp. 80, ammonia, nitrite and nitrate 0, calcium 450, Alk 7. I started to have trouble with the trigger after I rearranged my power heads in an attempt to eliminate dead spots in the aquarium. The next day the trigger was hiding under her sleeping rock but came out to eat at chow time. The next day wedged under the rock again, this time it wouldn't eat. Third day the same behavior, move to quarantine tank. <I would wait a week or two here... Triggers are given to such behavioral changes with slight changes in their environment> No treatment as yet because I have no idea what is going on. The other tank inhabitants are a small Scopas tang, a lawnmower blenny, a yellowtail blue damsel, a maroon clown, a large thriving sebae anemone, a long spine urchin, a pencil urchin, a coral banded shrimp, a cleaner shrimp, and various hermits and snails. <Am very surprised that the trigger has not (yet) consumed the last few> Nothing else is showing signs of distress. Filtration includes an emperor 400 with the bio-wheels removed and an aqua-c remora pro skimmer. I think it may be too late for her as she has stopped eating and swimming altogether, but does not have any other overt visible sign if stress or disease. Her diet included Formula One and Two soaked in Zoecon, frozen Mysis shrimp also soaked in Zoecon and lastly Wardley's freeze dried plankton also soaked in Zoecon. This is very distressing as this was the second fish added to the system after the tank was cycled nearly eleven months ago.     Thank you ever so much, Mike <Do try both an opened clam and on another occasion a "cocktail shrimp" (sans sauce of course)... and replace the trigger in its larger/est system. Bob Fenner>

Trigger System/Choices II - 02/27/06 Eric, <<Hello Bill>> THANKS for the very prompt reply. <<Very welcome>> I'm not sure but last post may have been misleading. <<Mmm, okay...>> The 90 gallon tank is going bye-bye, unless I decide to use it for my sump/refugium.  (the sump on the 90 gallon Cichlid tank is a 40 gallon breeder) <<Ah, I see.>> I've been looking at a 135, or possibly a 180. <<The latter is the better choice.>> Both are glass, and drilled.  They include a stand and canopy, and whatever lights I decide for a very reasonable price. <<cool>> I'm guessing the 180 would be the best choice for the three triggers--the Niger, Picasso, and Bluechin/Throat using the 'rule' of 1" of fish per 2 gallons of water <<A useless rule my friend...as are so many such "generalizations"...all fishes are definitely NOT created equal.  You must take in to account such things as feeding habits, swimming behavior, temperament, developmental retardation (as in putting a Yellow Tang/Blue Tang/Sohal Tang/Naso Tang, etc., etc., etc., in a 55 gallon system!), and more.  Unfortunately there is no magic formula (or rule).>> --or is it just wishful thinking and still need to go bigger-- <<Considering adult sizes...would like to see you go bigger for the long-term.  I think you could likely get by with the 180 for some time, but the Niger Trigger will eventually outgrow even this tank (can reach 20+ inches in the wild).>> Your thoughts and recommendations are appreciated. Bill Fletcher <<Regards, EricR>> Trigger System/Choices III - 02/28/06 Eric; <<Bill>> Again my THANKS for the prompt reply--that is the main reason we all come to this site. <<Very welcome my friend.>> Well, I had always heard that bigger is better, and I really did want a bigger tank anyway. <<Your chosen fishes will be happier/live longer for it.  Let me know how things progress.>> THANKS again, Bill Fletcher <<Regards, EricR>>

Trigger Question... Odonus sys.   1/16/08 Hello All, First off, I would like to say I love the site! Very informative. <Welcome> Now to the questions--Currently I have a 20g FOWLR tank, 35 lbs of Live Sand, 35 lbs of Live rock, Hermits, Snails, 1 Atlantic Lettuce Slug, 1 Large Coco worm, and several baby feathers. I would like to add a Niger Trigger. <... not in a 20 gallon system> He is only 1.5 inch body size. I know he is not meant for a 20g, I will be setting up my 220g shortly, and let it cycle, plan on adding livestock in June. So I do not believe the Niger will outgrow the 20g by then. <I'd wait...> My question-- First off, I noticed in another answer you gave, to place "toys" in the tank to keep the Nigers busy. What would you consider a good "toy" for them? <Rocks placed where there are holes, caves to swim into and through here> Also--Will the Niger be ok in with my Coco worm? The Coco's tube is about 8 inches long, and a large crown. I am assuming, (But please correct me if I'm wrong) that I will need to get rid of my Atlantic Lettuce, I do not want to do this, but if that's what it takes to get the Niger, that is what it will come to. <The Odonus will "sample" all... eventually, likely to death. Bob Fenner> Thanks for your time!! Stace Also---Will I get a reply by email? Or will I have to search the site? I am hoping an email, but either way is fine. Thanks again!! <Ahh, we respond directly to all>

Triggerfishes for  Marine Aquariums
Diversity, Selection & Care
New eBook on Amazon: Available here
New Print Book on Create Space: Available

by Robert (Bob) Fenner

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