FAQs about Monos or Fingerfishes, Family Monodactylidae Related Articles: Scats and monos; Old favourites and new species for the brackish water aquarium by Neale Monks, Monos,  Related FAQs:  A Monodactylus sebae juvenile in captivity, likely captive produced.

saltwater mono tankmates      10/10/14 I have 3 mono argenteus that are 5-6" in size. <Nice> They are in a 60 gallon 4ft long by 2ft high by 1ft deep FOWLR. I have had them for about 4 years and just converted their tank a week ago to live sand and live rock (it was brackish before with river rock bottom, plastic decor, and slowly added salt till 0.023sg). <With a 1 in front of the decimal place> I used the same filters and most of the same water so it cycled quickly. My monos are in the tank with the live rock and all are healthy and happy. Nitrates are about 20 right now, rest is where it should be. (I have lights for corals I got for cheap so its an option to grow other things in future if i want to do that at some point.) I have a penguin 350 filter and a remora c hob skimmer (rated for up to 90g), about 40-50 lbs live rock. I want to add some tankmates and was wondering what would work well. <There are a few choices... but I want to encourage you to get a larger system for one... and to take your time in isolating/quarantining and slowly acclimating new specimens> I have hermit crabs, pencil urchin, brittle star, emerald crab, snails. I would ideally want fish that wont eat these so they can continue to help keep tank clean. My monos are typically not too aggressive with other fish aside from themselves or small enough to swallow fish but wondering if some fish will be intimidated by their size and quickness. Also my fish eat voraciously so wondering if shy or bottom dwelling species may not get a chance to eat. <Understood> They used to live with a silver and a green scat and a g. tile eel with great success. Unfortunately my water went to crap real fast and the scats and eel died within days of each other about a month ago. It was a really hot summer and water got up to 84-86 degrees. <Again; this would not likely have happened had the system been of larger, adequate volume... I'd look first to getting something at least twice the size you currently have... ahead of adding more stock> I think water temp or the increased salt killed all the Malaysian trumpet snails in the tank and that made water bad. Was really bummed out about the eel the most, he was very cool. Anyways back to the stocking.... Ideally I was thinking of a more community set up with a small tang (Kole or Tomini) because they eat algae and wont be competing with the monos, and a sand sifting goby , maybe a clownfish pair, reef safe wrasse or damsel fish? This way if i want corals ect in future I could do that. Although if monos are not reef friendly enough themselves to go that route going with an aggressive set up instead. <Could go with> If I went with aggressive tank get an eel and a fuzzy dwarf or other smaller species of lionfish, maybe a wrasse that wont get too big? <You already are out of room physiologically> Will my clean up crew survive ? if not are there other options for clean up crew for aggressive fish? <There are others... perhaps some sandsifting gobies will add interest for instance> I know I probably cant add too many more fish but figured I could add a couple at least. <Not now; no> Also i would prefer hardier fish too as I am a novice in saltwater fish keeping. I am also willing to upgrade to a canister filter if you think that's a better option or would accommodate more fish. <I'd add, have redundant filtration AND circulation here> Other suggestions are welcomed too. I attached a pic to show size of fish and tank. <Very nice indeed> Thank you for your time, Toby <Thank you for sharing. Bob Fenner>

mono with nostril additional info      10/10/14
I sent this message earlier and forgot to add that the fish is in saltwater 1.023 and has lived in salt water or very high end brackish for about 8 months, before that was freshwater and slowly acclimated to salt over the course about 3yrs. I just wanted to add that cause i goggled it and seems there is a hole in head disease for freshwater fish.
<Indeed. The extra info is useful. Just to be clear: Hole-in-the-head isn't a "freshwater" disease as such. It can be caused by a variety of problems, though two culprits have been suggested. One is a parasite called Hexamita, which seems to become a problem when fish are exposed to poor environment for too long, typically high nitrate levels in overstocked tanks. The second culprit is a lack of vitamins, most often where herbivorous or omnivorous fish haven't been given any fresh greens (or at least foods fortified with vitamins to replicate this). In marine tanks HITH is often substituted with a disease called Head-and-lateral-line Erosion, HLLE, and whether HITH and HLLE are the same diseases with different symptoms is unknown to me. In any case, their causes and treatment are essentially identical: Metronidazole, together with improved diet (use of fortified foods and/or marine aquarium "HUFA" vitamin supplements) and water quality, in particular efforts to reduce nitrate level (less food, lower protein food, more volume of water, more water changes).>
I have a mono argenteus that appears healthy and is eating. I have had it along with 2 others for about 4 years. I just noticed that one of its nostrils is much bigger than the other as well as all the other fishes nostrils. It doesn't look raw or pink or discolored but it appears eroded away. Like a hole in its head. Its good nostril is little bigger than a pinhead, the other is about the size of a BB or shotgun pellet or about
this big O . The fish is about 5-6" for reference.
Should i be worried?, maybe its been like that for a while and I didn't notice it.
<Possibly. I would indeed suspect HITH or HLLE, and treat accordingly.
Monos aren't especially delicate, and if the fish is still happy and eating, the outlook is good in terms of stabilising things, and quite possibly undoing some of the damage too.>
Thanks,
Toby
<Cheers, Neale.>

Compatible eels... BR, Mono comp.   1/24/11
How are you?
<Just fine, thanks!>
I'm looking into adding an eel into my 55 gallon tank. Right now I have a pair of monos.
<Which need brackish water now, and preferably saltwater once mature, limiting your options.>
I do plan on getting a few more of them and maybe a few more different type of fish.
<Monos will outgrow 55 gallons pretty quickly; you really need 150+ gallons to get the best from them. They can be aggressive towards one another, and in small groups sometimes the biggest one becomes a bully. Be careful. Read up on the needs of Monodactylus argenteus carefully.>
I would like to know which eel would be the best fit.
<None, really. While a Fire Eel or Tyre Track eel might work in a low salinity system, up to SG 1.005 at 25 C/77 F, this won't be an ideal combination because of the Monos. The so-called Freshwater Morays are of course brackish to marine species, and while suitable for big brackish water tanks with Monos, the reality is that some Morays become "snappy" and cause problems. Echidna rhodochilus is perhaps the best bet because it feeds mostly on invertebrates, but Gymnothorax tile is the most commonly traded Moray and is a fish-eater, so that bit more likely to cause problems.>
My pH is at 7.6 and I have it set up with a lot of rocks and caves and some fake plants. Maybe an eel isn't a good idea?
<This is usually true.>
And also if you guys could tell me a few types of fish that would mix well in these conditions. I was told some freshwater puffers
<None of the freshwater puffers is suitable for mixed species set-ups, with the possible exception of the South American Puffer.>
and maybe a clown knife?
<Can't be kept in brackish or salt water, so not suitable for life with Monos.>
Thank you
<Hope this clears things up for you! Cheers, Neale.>
Re: Compatible eels 1/24/11
The monos I purchased are the ones with the black stripes.
<Monodactylus sebae, also known as the West African Mono.>
Are they the same as the yellow fin ones?
<In terms of care, yes, exactly the same. They do get bigger, or at least deeper, so you need a very deep aquarium for them. Adults are typically 20 cm/8 inches deep, so your tank will need to be at least 60 cm/24 inches deep.>
Well what would be a good mix with these fish at the pH 7.6?
<pH isn't the issue; salinity is. These Monos need brackish to marine conditions, SG 1.005 to 1.025. The ideal is probably around SG 1.010 at 25C/77F. Assuming you're using marine salt mix at an appropriate amount (about nine grammes per litre for SG 1.005 at 25C) then the pH should automatically set at around 8. So choose companions that need the same middling brackish or marine conditions. Most people keep their Monos either with hardy brackish water species -- Mollies, Scats, Archerfish -- or else with robust marine species such as Damselfish, Surgeonfish and Lionfish. At higher salinities you can also use a skimmer, and this does seem to improve Mono health; Monos come from the highly oxygenated surf zone part of the sea, and they dislike old, stale water. Monos kept in freshwater rarely do well for long, and tend to be prone to diseases such as Pop-eye and Fungus.
Do read about them on my Brackish FAQ or in my book:
http://homepage.mac.com/nmonks/Projects/FAQ/3a.html
Cheers, Neale.>
Re: Compatible eels  1/26/11
Ok thank you. All I have done so far is add aquarium salt
<Marine aquarium salt. Not "aquarium salt" or "tonic salt". If it isn't what you use in a marine aquarium, it won't do in the long term.>
as required for a 55 gallon tank. The monos seem to be doing fine.
<Yes, they are hardy, at least when young. Above a certain size they do become very easy to kill. Look for nervousness and/or turning black. These are warning signs!>
I don't know anything about salinity
<Much here at WWM.>
and I'm very new to cichlids
<Monos aren't cichlids.>
and I want to do the best possible. Right now I'm feeding them Freeze dried bloodworms and I do have some frozen ones for when I have a more populated tank.
<Will need a more varied diet than this. A good staple is Hikari Cichlid Gold. Augment with bloodworms, chopped seafood, and especially strips of tilapia fillet.>
I have a friend that has a tank full of African cichlids.
<Do you mean Mbuna? The rock-dwelling cichlids of Lake Malawi? Far more types of cichlid in Africa than just these!>
I think they are all peacocks and zebras or something, and one of them was killed but the other seems to be doing fine.
<What's happened is very common. Pseudotropheus zebra cannot be kept with Aulonocara (i.e., Peacock cichlids). Pseudotropheus zebra is a Mbuna cichlid, a very aggressive and territorial rock-dwelling species.
Aulonocara spp. live more in the open and they are MUCH less aggressive.>
Are these fish something I can consider adding to my tank?
<No. Salt causes Malawi Bloat for one thing. Look instead at Scats or Archerfish, or perhaps even Giant Sailfin Mollies. If your retailer can get them, Black-chin Tilapia would also work, as would Green Chromides (Etroplus suratensis), both of these being brackish water cichlids and very interesting fish at that. Black-chin Tilapia for example are paternal mouthbrooders, something very rare among cichlids.>
And food wise, I also have Hikari pellets and I was thinking about mixing everything together.
<Hikari pellets are a very good food for Monos.>
Sorry to be a pain but am I doing everything good so far?
<Seem to be doing mostly okay, but read, learn, and ask questions! Cheers, Neale.>
Re: Compatible eels, BR   1/27/11
Ok so if I already added aquarium salt,
<Which will fine for now. But once the box runs out, switch to marine aquarium salt mix.>
and I buy marine salt, should I do a water change first or what is the right process of getting the right salt in the tank?
<No need. Just switch to marine aquarium salt mix as/when the aquarium salt is used up. Aquarium salt is poisonous or anything like that. It just doesn't work particularly well, and in the long term will not be good
enough. But for a few months, it won't do any harm.>
Also, how about live brine shrimp? At the store I get them I think they are in salt water. I'm always told to rinse first before adding them to my freshwater community tank. Would this be a good food option for them?
<Yes, will be fine for Monos, and no, you won't need to rinse it off. Just pour the whole package, salty water included, into the brackish water aquarium. Cheers, Neale.>
Re: Compatible eels  1/27/11
Also I'm sorry I didn't explain in detail about my friends tank. He bought 2 mono sebae and one was killed
<By the Mbuna.>
and the other is doing fine.
<For now. Will eventually be either killed by the Mbuna or die from sickness because it's being maintained in freshwater. Monodactylus sebae needs brackish to marine conditions. It has no place in a Rift Valley
cichlid aquarium.>
He has those rock dwelling cichlids.
<They're called Mbuna. Cheers, Neale.>
Re: Compatible eels  1/27/11
Neale thanks a lot for all your help I know I asked you this before but if you could point me in the direction of some fish that would be nice in the tank I'd appreciate it. Not sure if invertebrates would work but I'm up for anything or any type. Thanks again
<Monos will get along with almost anything they can't eat whole. The question is whether you intend to keep them in brackish or marine. Classic companions for aquarists into predators are Colombian Shark Catfish and/or Siamese Tigerfish (though not all are brackish water species, so check).
http://www.wetwebmedia.com/ca/volume_7/volume_7_1/ariidae.html
http://www.wetwebmedia.com/brackishsubwebindex/siamesetigrfsh.htm
If you want something that becomes tame, then try Scats, the Silver Scat especially being extremely beautiful. The two Mono species traded mix extremely well, and if anything, mixing them seems to break down their tendency to become aggressively territorial. Not sure why. Violet Gobies would make neat "eel-like" fish though their dietary requirements are quite specific, so do review before purchase. Some of the big sleeper gobies make good companions as well, including Dormitator maculatus and Butis butis.
http://www.wetwebmedia.com/monos.htm
http://www.wetwebmedia.com/brackishsubwebindex/bracfishes.htmThere are a lot more brackish water species traded than just these, but finding them may require a bit of effort. Try perusing my Brackish Water FAQ for some more ideas, and then ask your local retailer what he can get in.
http://homepage.mac.com/nmonks/Projects/brackishfaq.html
Under marine (or at least near-marine, SG 1.018+) conditions your list of tankmates can include Damselfish, Wrasse, Lionfish, Snappers, really anything of similar size that won't view the Monos as prey. If you visit public aquaria, you'll see Monos used extremely often as "dither fish" for giant reef tanks.
Cheers, Neale.>

Slightly concerned about my Monodactylus Sebae. 3/2/11
I have been browsing the FAQ section on your website and have been unable to find an answer for my question.
<Let's see...>
I have a 60 gallon brackish setup that I keep three 2.5" Monodactylus Sebae , two 2" Ruby Scat, and two 2" Mollies in. The PH is around 8.2, SG 1.012 , ammonia 0, nitrates 0, nitrite 0, 80 degrees Fahrenheit, with very hard water. I have around 8x/hr filter turnover and 2 airstones in the outlet of my filter to increase oxygen levels.
My problem, however, is this.
One of the three Monos is getting very dark and acting very aggressive towards the other two.
:<Ah, not atypical...>
Neither of the two remaining Monos are acting very stressed about this, their color is still very bright , they don't seem to hide in my fake plants very much. The dark mono is growing much faster than the other two as well, and is obviously dominant. I am just wondering if I should be worried about him.
<Yes; and more so for the other two>
Most other posts I saw involved the submissive Monos getting dark, or the coloration changing due to environmental factors or stress... but everything seems fine.
Thanks in advance,
Kenneth
<IF you have another established system, I'd be moving the dominant/larger individual to it... or if this were a much larger system (100 plus gallons) maybe all three. The dominance/bullying is not likely to end here (in the sixty)... In the shorter term, I'd place the larger Mono in a plastic floating colander for a few days to see if (hopefully) this results in it becoming less alpha. Bob Fenner>
Re: Slightly concerned about my Monodactylus Sebae. 3/4/11
Thank you, I will try the colander first and if that doesn't do the trick I will separate him from the other two. They get along fine so I'm hoping they will be okay together.
Kenneth
<This four foot tank will be too small eventually... BobF>
Re: Slightly concerned about my Monodactylus Sebae.
Well, I have an update. My tank suddenly began to crash at some point today. Why, I'm not very sure. I caught it pretty quickly though and managed to do some serious water changes (about 60%) and stabilize all of my parameters. Now my Monos are all schooling together peacefully though.
All three are bright silver and acting fine, unlike earlier when they were behaving like they had hours to live. I will keep an eye on their behavior for a while now though, just to be safe.
<Okay. B>
Re: Slightly concerned about my Monodactylus Sebae.
I plan on upgrading soon to 100gal or more , until then this is just temporary.
<Ah good. B>

Sciades seemanni and Mono Questions. Acclim. to BR from FW  -- 3/3/10
I currently have a 125 gal marine tank with 2 lionfish, a snowflake eel, and one Sciades seemanni Columbian Cat.
<Mmm, this last is a social animal. Much happier w/ some of its own kind>
I almost bought a trigger until I read that the triggers hate the cats clicking noises. I am contemplating selling all bought <but?> the cat and converting to a brackish environment. I read that the cats do better in groups.
<Many species do>
My current cat is 7 to 8 inches. I want to get 1 or 2 more but cannot find them large enough. If I buy a 2 or 3 inch cat, will the larger one be aggressive toward it?
<Not likely, no>
My second question is about acclimation. I wish to add Mono argenteus and Sebae but these are almost always sold in freshwater. I was told that you can almost take them directly from fresh and put them into a marine environment. Is this true?
<Yes>
Can I do the same with archers and the cat?
<To a lesser extent, weeks instead of days, yes>
Or am I safer to set up another tank to slowly convert them to marine or brackish? Thanks for the help!
<This last is a much safer, better approach. Bob Fenner>
Re: Sciades seemanni and Mono Questions, more re acclim. to SW, impt. notes re Toxotids, ID and sys.
Hi Bob,
<Neale>
I just saw your reply to one brackish one about monos and catfish.
<Yes... responded as it was over a "day" back/old>
Would just add this: You are quite right that (subadult to adult) Sciades catfish and (any age) Monodactylus can be converted to marine conditions quickly. I'd use the drip method across an hour, as if they were swimming through an estuary, but yes, you could in theory dump them straight in.
<Ahh, please do send your input to the querior as well>
But Archers are a whole other kettle of fish. There are three species in the trade, each equally widely sold, and one of them is a freshwater to low-end brackish species, Toxotes microlepis.
<Rare in the U.S.>
It will die kept in marine conditions for any length of time. Frankly, it's unhappy above about SG 1.005. The other two species, T. chatareus and T. jaculatrix, will tolerate marine conditions though they're best kept around SG 1.010.
<Definitely send this along as well>
Diagnosing the three Archer species is tricky, but there are some drawings that should help on my web site, here:
http://homepage.mac.com/nmonks/Projects/FAQ/3c.html
Cheers, Neale
<Thank you. BobF>
Sciades seemanni and Mono Questions
<<By way of a follow-up to Bob's reply. I would just add this: Bob is quite right that (subadult to adult) Sciades catfish and (any age) Monodactylus can be converted to marine conditions quickly. I'd use the drip method across an hour, as if they were swimming through an estuary, but yes, you could in theory dump them straight in. But Archers are a whole other kettle of fish. There are three species in the trade, each equally widely sold, and one of them is a freshwater to low-end brackish species, Toxotes microlepis. It will die kept in marine conditions for any length of time.
Frankly, it's unhappy above about SG 1.005. The other two species, T. chatareus and T. jaculatrix, will tolerate marine conditions though they're best kept around SG 1.010. Diagnosing the three Archer species is tricky,
but there are some drawings that should help on my web site, here:
http://homepage.mac.com/nmonks/Projects/FAQ/3c.html
Bob believes that Toxotes microlepis rare in the US market, but German author Frank Schaefer argues it is the most widely traded. My own experience is that all three species occur roughly as often as each other,
and I've seen specimens of all three species on both sides of the Atlantic.
So do check which Archerfish you have before acclimating them to saltwater conditions. Cheers, Neale>>

Re: Sciades seemanni and Mono Questions 3/3/10
You both gave me great info. Thank you.
<You're welcome.>
The next step is convincing my wife to let me get rid of the lions and eel and replace them with monos...she likes the salt water fish more than I do lol!
<Why not keep the Lionfish and the Eel, add the Catfish and the Monos, and rehome the Archerfish? Cheers, Neale.>

Monodactylids and Crustaceans... comp. if of size   5/24/10
Hi Bob,
I wrote a while back about a problem I was having with gorilla crabs that came in on some live rock. I still have the crabs, despite flushing all of the rocks and getting about 60 off them, and going every 2 nights with a chopstick and forcing some to become shrimp food. The porcelain crabs are growing in number (somehow, I ended up with breeding populations of every hitchhiker), to the point where I'm starting to fear that they will end up
being a pest due to lack of food to filter.
<Mmm, I'd be looking into purposeful predator control here>
I still have an Aiptasia semi-problem (slow spread, so nuking is effective at maintenance but not extinction), but haven't tried a peppermint shrimp yet. While I was looking around for biological controls for Aiptasia, I noticed that monos can be kept in full marine conditions, and have only small fish and crustaceans listed as an explicit food source.
Are monos known to eat anything and everything as scats are, or do they have a particular taste for small crustaceans over other food?
<Eat a good deal of what Scatophagids do... algal, small animal wise>
Are they a fish that will eat echinoderms, Polychaete worms, corals, Aiptasia (that would be awfully convenient), shrimp larger than themselves, Polyclad flatworms (another convenient food source), whelks, other snails or macroalgae?
<Mmm, not larger invertebrates... See fishbase.org for Monodactylus spp.; their foods>
I know I listed nearly everything, but particulars of the eating habits of monos in marine settings seems to be elusive information.
Thanks a lot! (< fixed on the third try)
<Good>
Andrew Angrist
<Bob Fenner> 

Sciades seemanni and Mono Questions. Acclim. to BR from FW  -- 3/3/10
I currently have a 125 gal marine tank with 2 lionfish, a snowflake eel, and one Sciades seemanni Columbian Cat.
<Mmm, this last is a social animal. Much happier w/ some of its own kind>
I almost bought a trigger until I read that the triggers hate the cats clicking noises. I am contemplating selling all bought <but?> the cat and converting to a brackish environment. I read that the cats do better in groups.
<Many species do>
My current cat is 7 to 8 inches. I want to get 1 or 2 more but cannot find them large enough. If I buy a 2 or 3 inch cat, will the larger one be aggressive toward it?
<Not likely, no>
My second question is about acclimation. I wish to add Mono argenteus and Sebae but these are almost always sold in freshwater. I was told that you can almost take them directly from fresh and put them into a marine environment. Is this true?
<Yes>
Can I do the same with archers and the cat?
<To a lesser extent, weeks instead of days, yes>
Or am I safer to set up another tank to slowly convert them to marine or brackish? Thanks for the help!
<This last is a much safer, better approach. Bob Fenner>
Re: Sciades seemanni and Mono Questions, more re acclim. to SW, impt. notes re Toxotids, ID and sys.
Hi Bob,
<Neale>
I just saw your reply to one brackish one about monos and catfish.
<Yes... responded as it was over a "day" back/old>
Would just add this: You are quite right that (subadult to adult) Sciades catfish and (any age) Monodactylus can be converted to marine conditions quickly. I'd use the drip method across an hour, as if they were swimming through an estuary, but yes, you could in theory dump them straight in.
<Ahh, please do send your input to the querior as well>
But Archers are a whole other kettle of fish. There are three species in the trade, each equally widely sold, and one of them is a freshwater to low-end brackish species, Toxotes microlepis.
<Rare in the U.S.>
It will die kept in marine conditions for any length of time. Frankly, it's unhappy above about SG 1.005. The other two species, T. chatareus and T. jaculatrix, will tolerate marine conditions though they're best kept around SG 1.010.
<Definitely send this along as well>
Diagnosing the three Archer species is tricky, but there are some drawings that should help on my web site, here:
http://homepage.mac.com/nmonks/Projects/FAQ/3c.html
Cheers, Neale
<Thank you. BobF>
Sciades seemanni and Mono Questions
<<By way of a follow-up to Bob's reply. I would just add this: Bob is quite right that (subadult to adult) Sciades catfish and (any age) Monodactylus can be converted to marine conditions quickly. I'd use the drip method across an hour, as if they were swimming through an estuary, but yes, you could in theory dump them straight in. But Archers are a whole other kettle of fish. There are three species in the trade, each equally widely sold, and one of them is a freshwater to low-end brackish species, Toxotes microlepis. It will die kept in marine conditions for any length of time.
Frankly, it's unhappy above about SG 1.005. The other two species, T. chatareus and T. jaculatrix, will tolerate marine conditions though they're best kept around SG 1.010. Diagnosing the three Archer species is tricky,
but there are some drawings that should help on my web site, here:
http://homepage.mac.com/nmonks/Projects/FAQ/3c.html
Bob believes that Toxotes microlepis rare in the US market, but German author Frank Schaefer argues it is the most widely traded. My own experience is that all three species occur roughly as often as each other,
and I've seen specimens of all three species on both sides of the Atlantic.
So do check which Archerfish you have before acclimating them to saltwater conditions. Cheers, Neale>>

Re: Sciades seemanni and Mono Questions 3/3/10
You both gave me great info. Than you.
<You're welcome.>
The next step is convincing my wife to let me get rid of the lions and eel and replace them with Monos...she likes the salt water fish more than I do lol!
<Why not keep the Lionfish and the Eel, add the Catfish and the Monos, and rehome the Archerfish? Cheers, Neale.>

re: Sciades seemanni and Mono Questions (RMF, Pterois/Dendrochirus in brackish water?)<<No>>    3/7/10
I wouldn't have the space for lions, eels, and Monos.
<Oh, I see.>
I really like Monos and would want a bunch of them.
<A good approach. If you can, add a Scat or two; the combination seems to break up some of the tension that exists in schools of just Monos, possibly by providing a "threat" of some sort that stops any of the Monos becoming secure enough to feel dominant.>
Additionally, I want the estuary look and I don't think you would find Lionfish and snowflake eels there. I may be mistaken, but do they ever wander into river openings?
<I have read reports of Dendrochirus in brackish water, specifically Dendrochirus brachypterus and Dendrochirus zebra, but I don't know if they ever become resident in brackish water for long periods. Certainly both Pterois and Dendrochirus tolerate relatively low salinities (SG 1.018) indefinitely, and technically, that's brackish water, but I wouldn't ever recommend keeping them in a "true" brackish water system at SG 1.010 or less. On the other hand, there are various truly brackish water
Scorpionfish of various types, some of which are traded: Notesthes robusta, Neovespicula depressifrons and Batrachomoeus trispinosus in particular. Of these, Neovespicula depressifrons is wonderfully active and easily tamed, but at only 10 cm/4 inches once mature, might not be completely safe with substantially larger predatory fish. Being venomous, the danger would of course be to both predatory and prey!>
I bought 2 small Sciades Seemanni and began acclimating them overnight.
When I woke up the next morning they were swimming upside down with bloated stomachs. It appeared that the bloated stomach was buoyant and caused the upside down swimming. I let them go into the main tank and the lion decided to try to make a meal out of one (I knew this was a risk, but the cat was upside down and not swimming normal so he was extra vulnerable). I put the other cat in a quarantine container within the tank. His stomach seems smaller now and he is no longer swimming upside down. He looks better and time will tell if he will get back to normal. Is this a normal reaction to being acclimated to saltwater? Thank you.
<Were these freshwater catfish being adapted straight to saltwater conditions? If so, yes, it's quite common for some species to have problems with equilibrium. The swim bladder has to change to match the different density of seawater (which is more buoyant) compared to freshwater. Should be fine within a few hours. Catfish are physostomus, meaning they need to "burp" out the excess gas from their swim bladders. More advanced fish like Monos are physoclistous, and can absorb excess gas directly into their bloodstream. Cheers, Neale.>

Sick Monofish -- 07/28/09
Hello
<Hi,>
I have one mono and 2 green spotted puffers (all young), they have been in the tank for 6 months now and so far all has been well. They are kept at 1.007ish salinity and as of 5 minutes ago ph was 7, and ammonia, nitrites and nitrates were zero.
<Why's the pH so low...? At SG 1.007, the pH should be at least 7.5.>
He is very listless and is spending lot of time just floating around with his nose on the surface of the water. I did notice he has breathing rather rapidly over the previous 2 days but that seems to have stopped.
<Do review circulation, oxygenation, and water temperature. Monos are classic "surf zone" fish and they are hyper-sensitive to stagnant, oxygen-poor water. Given enough oxygen, they're tough as old boots, but if the water lacks sufficient circulation, they turn grey, gasp, and sicken very quickly.>
The only signs I can see are a slight whitening around the tip of his bottom fin and his tail fin is very very slightly raggedy but I cannot see signs of a white fungus on the tail.
<Fungus is fairly rare in brackish/marine conditions.>
I wondered if it was ich but I cannot see any spots of any colour at all.
I always thought fin rot did not actually make them appear ill?
<Finrot isn't a disease as such; it's what happens when a fish is sufficiently damaged and/or stressed that opportunistic, otherwise harmless, bacteria can breach the fish's normal defences and cause infection.>
I know mono's are school fish and I had intended to get two more, but my local pet shop stopped stocking them and the three fish seem to get along quite happily so I was loathe to upset things.
<They're fine in small groups like this.>
I do not think the puffers are attacking him as they all spend the night quite close to each other in the volcano and I have never observed aggression between them.
<Do be careful though. Fighting between Monos is common, and GSPs are notorious fin-biters as well. Fin damage easily becomes Finrot, and aggression can suppress the immune system, allowing Finrot to get started.>
The only thing I have done differently lately is move house about three weeks ago. He eats mainly blood worms and has never shown any interest in flake food or lettuce etc - could it be a nutrition problem?
<No... I'm actually wondering if there's intraspecific aggression going on here, i.e., the three Monos, after being moved, are now picking on one another as they squabble over dominance. Although schooling fish, some people have found Monos so hierarchical that they've ended up with just one specimen, or a (presumably) matched pair.>
Perhaps it is simple Finrot and I am being over cautious but I would hate to lose him and just want to check if it could be something I haven't thought of..
<Would treat for Finrot, but also observe for aggression/fin biting, and review environmental issues.>
Many thanks
Sarah
<Cheers, Neale.>

Re: Sick Monofish -- 07/28/09
Neale
<Sarah,>
Thanks very much for such a quick response. I am quite surprised how worried I am about a fish!
What can I do to lower the ph?
<Lower it? You want to raise it! For Monos, something in the range 7.5-8.5 is the order of the day. A low pH could easily be the stress factor on this Mono, and should be considered before going on. Indeed, most brackish water fish are prone to Finrot when kept in soft, acidic water.>
The temp is 26-27 degrees. I am wondering about the oxygen thing as he is def sat with his mouth to the surface (do they get swimbladder problems?).
<Many fish will "gasp" at the surface when stressed, so it's difficult sometimes to know if it's [a] a genuine breathing problem; or [b] stress from something else. As for swim bladder complaints, no, Monos aren't particularly prone to them.>
I have a air bubbler and then the normal tank filter system which appears to be working ok so I am not sure what else I can do. Is there any way to test the oxygen in the water?
<You really can't, but you can deduce whether the tank *should* have enough oxygen. First up, you review stocking. The "inch per gallon" rule is okay for small fish, but once fish get about the size of a Gourami or angelfish, it doesn't really work. (Take an extreme case: twelve Neon tetras and one adult Oscar have the same length in inches, but clearly the Oscar needs much more space than the twelve Neons.) An old rule I like says to allow ten square inches per inch of fish length. Again, it's an estimate, but it's a conservative one, and if your aquarium works out with that rule, you're probably fine in terms of surface area. Next, review circulation. This is critical! At minimum, the filter should turnover the volume of any aquarium four times per hour, and for oxygen-loving fish like Monos, I'd increase that to at least 6, and ideally more than 8, times the volume of the tank. So for a 30 gallon tank, I'd want a filter turnover of 6 x 30 = 180 gallons per hour, and ideally, 8 x 30 = 240 gallons per hour.
You'll find the turnover printed on the filter itself or on its packaging.
Finally, look for signs of stagnant water in the tank. Does debris collect in one spot? Can you see blue-green algae on the substrate? Both of these are signs that water isn't moving as well as it should. Upgrade the filter, move airstones about, adjust filter outlets until you're happy water is moving about nicely.>
I did a 20% water change this evening and it doesn't seem to have perked him up at all. Maybe I should change another 20%?
<Sure. In fact, change 50%. Brackish water fish are, by their nature, tolerant of big changes in water chemistry. If you see the Mono pep up, then it's a good sign there's something amiss. Do check the water chemistry of what you're adding. At 26 degrees C, 12 grammes of marine salt mix per litre will produce a specific gravity of 1.007. Do download and try out my Brack Calc application to see how to convert between temperature, mass of salt used, and specific gravity if you want; it's free, and works on Macs and PCs. Anyway, such water should have a high degree of alkalinity, and I'd expect a pH of not less than 7.5. If you aren't getting a pH like that, you're probably not adding enough marine salt mix. Do also remember than cooking salt, tonic salt, aquarium salt, etc don't contain alkalinity, and won't raise the pH. It has to be marine salt mix! If even after adding marine salt mix, you still get a low pH, read here:
http://www.wetwebmedia.com/FWSubWebIndex/fwh2oquality.htm
Try adding the Rift Valley salt mix at half or full dosage; it should raise the alkalinity and pH nicely.>
I think I may have confused you - I actually only have one mono at the moment - he has seemed fairly happy so far with the arrangement and hangs out with the puffers quite a bit, but maybe he is lonely. I don't really want to get any more until I have sorted him out though.
<Agreed.>
Thanks
Sarah
<Cheers, Neale.>

Re: Sick Monofish -- 07/28/09
Hiya
Sorry to be a pain
The mono is now swimming madly round in circles and seems really distressed.
<Change 50% of the water, immediately. Observe. Review filtration, water chemistry, salinity. Most sick Monos are sick because of their environment.
Oxygen, acidification are the key issues.>
I think it must be a parasite of some kind. It seems really in distress - is there and kind way to kill it? The puffers are ok at the mo but I am wondering if I should use a parasite treatment to be on the safe side?
<No.>
Thanks
Sarah
<Cheers, Neale.>
RE: Sick Monofish
Ok that's what I'll do - Thanks very much for your help and advice.
Sarah
<Happy to help. Good luck! Cheers, Neale.>

Acclimating Monos
Greetings, How long should it take to acclimate Monos from brackish water to salt water?
<The salinity change isn't actually a big deal, as Monos and Scats can both adjust to dramatic salinity changes very quickly. They have to; in the wild, they're constantly moving around between rivers and the sea. If the salinity in the brackish water tank is 1.010 or more, you can simply remove them from the brackish tank and add them to the saltwater one directly. If the salinity is less than this, some degree of adjustment across, say, 30 minutes will probably be less alarming to them. On the other hand, Monos
can react very badly to being confined in a bucket, especially adults.
Likely this is related to them being surf zone fish and specifically adapted to high oxygen environments. If you can, use an airstone to keep the water in the bucket moving, but at least make sure the bucket is big
enough that the fish aren't suffocating. Cheers, Neale.>

Questions regarding Mono... starting at square one...    8/5/08 Hi there: <Ave,> I have a question regarding Monodactylus Argenteus (Finger Fish). <Oh?> I just made a small sized aquarium (30 gallons) and had purchased some angelfish and a pair of Monos (though I didn't know the species was a mono then). The dealer was calling it as 'Sea-angel'. However, the fish (both) started behaving very oddly-such as swimming upside down and trying to dig into the gravel. One of the Monos died the next day, the remaining one was barely breathing. After much search on the net, I got to understand that the species was a Mono and it needed the required concentration of salt. I put a handful into the tank, within 20 min.s, the Mono was up and running. This was a week back. <Monos need more than a bit of salt; upwards of 9 grammes marine salt mix per litre (about 1.2 oz per US gal). They are really brackish water fish and can't be combined with freshwater fish. They need their own aquarium, or at least one that they can share with other brackish water species like scats and archerfish.> I was apprehensive initially of the other angelfish and gouramis (dwarf neon, honey) whether they would take the salt content. <They won't. Not long term anyway.> Everything seemed fine. All are eating well, the Mono is really fast across the tank and generally aggression was minimum. Yesterday I did a 40% water change (coz my ammonia levels where spiking) and today, the mono started becoming slightly dark. it is still active (its major past time is swimming in front of the filter pump), however I didn't see him eat today. My question: <Yes, Monos are sensitive to ammonia and will react by going dark.> a) Do I have to add more salt (considering that I did a 40% water change). <Long term, they certainly will need brackish water conditions. Monos will do well in hard, alkaline water for a while, weeks at least, perhaps months. But they become very nervous and skittish, and prone to disease when kept permanently in freshwater.> If so, can I add normal table salt? (which has iodine) <No.> b) Will the salt affect my other species? What about plants? (Its a planted aquarium) <Salt will harm any plants and fish not adaptable to brackish water. All your fish, and likely many of the plants.> c) What SG should I aim for. I believe it should be slightly less than Brackish. If I want to convert into a complete freshwater tank, will it affect the Mono? (gradually) <Doesn't work this way. Monos are brackish water fish. End of discussion really. Attempts to keep them in freshwater or freshwater "with a hint of salt" won't work.> d) What would be a correct % of water change? <25-50% water changes per week is what I recommend for any fresh or brackish aquarium.> Would appreciate a response. Thanks a lot and keep-up the good work. Philip <Do read here: http://www.wetwebmedia.com/scatsmonosart.htm http://www.wetwebmedia.com/BrackishSubWebIndex/bracsystems.htm Cheers, Neale.>

Porcupine Puffer... sys. trouble, and Mono sel.   - 4/12/08 Hi WWM Crew, <Robbie> I've been reading the site for the better part of the day and decided to write you in case I missed something. I've had a porcupine puffer (Puffy) for about 5 years. He was moved into a 240 gal tank about 6 months ago. All fish tank includes 3 triggers (Bursa, Picasso, Niger), <Mmmm> Foxface, 8 damsels, flame hawk. Last weekend Puffy started hiding in the cave and stopped coming out for food around Monday or Tuesday this week. Last Sunday I lost a mono. This past Monday I lost the other 2 monos. I had the water checked by a Santa Monica Aquarium shop and my "fish guy". Both found the tank elements to be perfect - except salt was a bit low. <What brand? How low?> Odd that the Monos - a brackwater fish died from low salt though. <Not likely> The salt was brought back to normal but Puffy did not improve. Today he came out of his cave and was found floating at the top of one side of the tank. I've tried feeding him peas (frozen, boiled, then skin removed) but he won't take them. <Not surprising> He had air in him earlier but my fish guy gently held and rubbed the belly and we did see air come out, about 4 hours ago. About 1 hour ago a ton of white stuff came shooting out of his mouth. Where he was swimming erratically earlier he is now "bobbing" in the upper 1/4 of the tank and barely breathing. He occasionally puffs in some water and eventually lets it out it appears. But he just "bobs" or sinks a bit and then floats back up. There is no sign of ick or other external disease. <Not pathogenic at least...> However, within the last few hours the edges of his fins have become a milky white. <Very bad... stress signs> On another note, my Foxface is having issues -- although I am more concerned about Puffy. The Foxface is swimming/bobbing in the same area of the tank. He usually is down at the bottom picking for poop. Now his mouth is just moving rapidly as he floats around in the 1/4 top section of the tank. Puffy to me is the equivalent of a dog to someone else. Its killing me to see him in pain and unable to do anything. Any idea what is going on? Thanks Robbie <Some form of overt chronic poisoning is my best guess... The usual S.O.P of massive water change/s, spiffing up your skimmer/ing, the use of chemical filtrant/s, possibly a look into the use of ozone... Something/s amiss here... could be electrical, dissolved gas, an endogenous microbial (crash) syndrome... But changing out water/dilution, better aeration/filtration will definitely help. The puffer though... is likely not going to make it. Bob Fenner> As an update to this. Hour and a half later Puff is now at the bottom of the tank and looks fatter in the back than normal. He is not using any of his fins, his mouth is just open, he is darker in color, and he is breathing slowly. <We'll see... BobF> Re: Porcupine Puffer.  - 04/14/08 Hey Bob, Thanks for the response. He didn't make it :,( Robbie <I do hope you are executing against a plan to save the rest of your livestock. BobF> Re: Porcupine Puffer.  - 04/14/08 Working on it. The problem is finding the problem. The puffer is the only one that showed signs of stress. The monos just "dropped dead". I literally watched one start acting odd and die in an hour. All are eating, all look and appear healthy. I'm no pro like you, but have had fish for about 10 years. Never experienced anything like this. I'm used to seeing the disease on the fish or see the chemical imbalance when I test. I am stumped. <Me too... thus the very general input our first correspondence... I would at least "complex" your system by adding a DSB, macroalgal culture, perhaps an ozonizer... B> Re: Porcupine Puffer.  - 04/14/08 Bob, <Rob> One thing we (me and fish maintenance guy) noticed fairly recently is this film on top of the water. <Bad... need to "wick" off, and provide for removal... from... food/s?> I have a center column with flow valves on either side. Only the left side has this "film" on top of the water. Its not dust but its this light brown color. No idea where its coming from or what is causing it. Maybe this has something to do with my fish dying? Robbie <Very likely so... can prevent oxygen from getting into solution... would explain much here in terms of who is dying first. Bob Fenner> Re: Porcupine Puffer dis., and Mono sel.  - 4/15/08 Hi Bob, <Neale> Re: the guy with the sick Diodon; if I'm reading the question right  and the "monos" that died are Monodactylus spp., then your observation of oxygen and the scum on the surface of the tank could be right on the money. While Monodactylus are basically bullet proof in terms of water chemistry issues, they are unbelievably sensitive to low oxygen tensions. Perhaps what you'd expect from a fish that lives in the surf zone and shallow coastal seas. <Yes... my inference as well> > If the fish are feeding fine one moment, then stressed/dead the next,  I'd be wary that the food I was adding was too oily, and those oils collecting on the surface of the water as a film. Usually only a problem if there's insufficient agitation of the water. A skimmer would obviously help, and is even recommended at SG 1.010 when keeping Monodactylus, let alone in a marine setting. But certain frozen foods as well as oil-rich dried foods can cause a similar scum to form. <Agreed all the way around> Incidentally, this oxygen issue with Monodactylus is one reason I recommend against buying mature specimens. They don't "travel" well. Cheers, Neale <Interesting and noteworthy. Will post to both categories. Cheers, BobF>

Acclimation of Mono Sebae to saltwater   2/27/08 Hello Crew, what a great justice ya'll do for everyone, I cant thank ya'll enough. But I have another question regarding Mono Sebae's and the ability (or length of time to acclimate them to pure saltwater). I have searched your site but cant find a definitive answer for this one. <Mmm, safely? Starting from pretty much freshwater? About a month...> First though, I have a 150 gal. reef tank: pH 8.2, Salinity 1.024, 0 ammonia, nitrites, nitrates, phosphates. Tank mates are: 3" Flame angel, 2" Royal tang, 2" Royal Gramma, 3" Neon wrasse, 2" Green Chromis, 2" yellow tang. There is no aggression within the tank between the fish. Now I want to purchase 3 2" Mono sebae's and introduce them to my main display (of course after qt), my qt biological filter is 1.024 and I am afraid it will crash if I lower it down to 1.014 to meet the initial needs of the mono's. How long is the acclimation of these fish from S.G. of 1.014 to 1.024? Can I do an extra long SLOW drip acclimation (1-2 days or longer) then add them into my qt? Thanks Again, Mike <Mmmm, start the QT tank SG at whatever the Monos are at right now... be ready with some nitrifying filter media adjusted to this salinity... raise the spg about a thousandth per day (by removing some water from the QT and replacing it with water from the main system... Bob Fenner>

Kissing Gourami and Mono Sebae problem... Oh yes   7/27/07 Hello, I have a 75 gallon tank with two neon tetras a Serpae tetra a scissor tail two Monodactylus sebaes and a kissing Gourami. they all get along fine but the two mono sebaes and the kissing Gourami. the mono sebaes don't seem to attack him because they don't chase him or bother him when he feeds but every so often if there real close to each other the Monos sebaes like pick at him once or twice on the body then leave him alone. But sometimes they don't pick at him when there next to each other. there is no damage being done. Is this something to be concerned about because its not like they chase him around the tank or continuously pick at him, or bite his fins its only maybe a pick or two the he swims away or they leave him be. Thank you Jason <Jason, you have one of the oddest collections of fish I've come across. Traditionally (i.e., when kept properly) tetras are kept in groups, not singletons. Neons are very nervous when kept singly or in very small groups. Really, for the Neons, Serpae tetras, and Scissortail rasboras these should all be kept in groups of 6 or more. Ideally more. Serpae tetras as I'm sure you know are only marginally suitable for community tanks because they are inveterate fin-nippers, and generally don't work well with slow moving things like gouramis. Now, your BIG problem here is that Monodactylus sebae isn't a freshwater fish. It wants a TOTALLY different environment to your tetras. As with all members of the genus Monodactylus, these fish are migratory and swim between freshwater and the sea their entire lives. In the aquarium, they are kept either in a medium-salinity brackish water tank (around SG 1.010) or else in a fully marine environment with marine fishes. In a freshwater tank they are apt to be disease prone and generally do not do well. It's a shame you didn't research this fish before buying it, otherwise you wouldn't have added it to this aquarium. Anyway, in terms of behaviour Monodactylus are semi-aggressive when kept in small numbers, and what they're doing is entirely normal. Ideally, transfer to a brackish or marine aquarium and add at least 4 more specimens. Alternatively, mix them with robust brackish water fishes like scats, Monos, and Colombian shark catfish. Hope this helps, Neale.>

Re: Kissing Gourami and Mono Sebae problem  7/27/07 Yes, well I tested my salinity and it shows to be 1.006 and I have researched and learned there are a few river opening to the ocean where brackish fish live that are about 1.005-1.008 but I am just wondering if I should remove my kissing Gourami or are they fine together none of the other fish tend to mind the salinity increase at all they tend to look healthier and eat more. thank you, Jason <Hello Jason. For real, you have neon tetras at SG 1.006? I'd never have believed that possible or even worth trying. While there are some tetras that occur in slightly brackish water (Pristella maxillaris for example) neon tetras aren't among them. Neons normally live in water with a very acidic pH (around 6.0 and almost no hardness. I'm actually surprised the serpae tetras and the Scissortails are alive, too. This is so far from the environment they prefer that I really can't recommend you continue keeping them under such conditions. Long term its unlikely to work out. It's placing an stress on the osmoregulation systems of these fish that you could do without. Now, as for your research: almost by definition brackish water occurs where rivers meet the ocean. (There are some exceptions where brackish waters occur far from the ocean, like the Caspian Sea for example, but we'll let that pass for now.) The only honest recommendation I can make is that the Monodactylus be given a brackish water aquarium and the freshwater fishes (everything else) be moved to their own freshwater aquarium. Your tetras, Scissortails, and Gourami want something like pH 7.0, low to medium hardness; the Monodactylus want pH 8.0, high hardness, and SG 1.010. There's really no "happy medium" they both will do well at, not in the long term. Bear in mind Neons live something like 4 years, and gouramis anything up to 10 years, so you need to plan ahead. Please have a read through the brackish water articles here at WWM, or better yet, go buy my book! There are so man y really cool brackish water fishes that it's a waste to keep Monodactylus in a 75 gallon tank with some deeply unhappy tetras and gouramis when you could be keeping some real gems like Butis butis, Selenotoca multifasciata or Mystus gulio. Look these up on Google and see what I mean! Cheers, Neale>

Mono floating upside down.   5/20/07 Hello, I have two Monodactylus argenteus in a 33 gallon with no tank mates. <Hello!> Last night both of them were fine, this morning one of them was floating completely upside down. <Eek!> It is still breathing but cannot right itself, just swims around upside down. <Assuming water quality is good, then diet *may* be the issue, and the old feed-it-cooked-peas trick might help "clear out" its insides.> The ph is around 7.8, a little high I know but they have lived in it for half a year. <That pH is fine. In fact anything between 7.5 and 8 hits the spot for monos. Hardness is also important though, and the water must be "very hard" on whatever scale you use.> The salinity is 1.008 and I cannot test for nitrites as my test kit has dried up. <Well, priority-one is get a new test kit. Monos are hardy and will tolerate nitrite and ammonia levels higher than those of marine fish, which is why they have been used to cycle marine tanks, but over the long term you can't expect them to put up with bad water. At the very least, do a 50% water change now, and another tomorrow, and go buy a new nitrite test kit ASAP.> I just did a 50% water change which seems to have made my upside down guy a little more active and that is about it. <OK, when fish improve when you change the water, that basically points to the fact water quality is an issue. Which usually means either the filter is clogged or you've done something unusual that messed up the nitrogen cycle bacteria. Either way, test the water, and act accordingly.> I have no idea what to do to help my little guy. If you have any suggestions I would really appreciate it. <Monos are lovely fish, but they are [a] sensitive to low oxygen concentrations and [b] easily damaged if they freak out. If monos turn black, that usually means they're stressed. On the other hand, they are essentially robust and usually recover when things improve.> Thank You Lacy <Good luck, Neale>

Converting a Mono argenteus from fresh to marine. Raising Freshwater to Marine  4/15/07 Hello WWM crew, <Hi Joe, Pufferpunk here> Just happened upon your website and I'm a big fan of what you're doing. <Thanks, we try our best!> Anyway, I've got a 4" Mono argenteus that I would like to start adapting from a freshwater tank to a saltwater tank. Any suggestions on how "fast" the change should be for best success? <You can raise the specific gravity .001-.002/week.  No faster or your tank's biological system can crash.  Measure with a hydrometer that starts at 0 (Instant Ocean or SeaTest are a couple of them).  A refractometer is even better.  I think your fish will be much happier.  ~PP> Thanks, Joe

Specific Gravity and Mono question  3/29/07 Hello everyone, <Hi Andy, Pufferpunk here> First of all, thank you for the help you have previously provided to me (and everyone else requiring assistance) on this site.  You guys are a tremendous asset!!   <Thank you & you're welcome!> Ok, I tried to find the answer to this on your site but couldn't seem to find it.  I have a couple of questions.   First, the background: 55gal BW tank, 2 emperor 400 filters.   Occupants:  2 Columbian sharks (about 4 inches long each), 2 GSP's (about 2 inches long) and 1 Monodactylus argenteus (sp), that is 6 inches long and tall.  I have been told that the SG should be around 1.014 but have noticed people on your site saying that BW is around 1.010.  What is the best SG for these fish? <BW is actually any SG between FW & SW.  High-end BW, 1.014 is fine.  Eventually those fish will be best kept in SW.  Then you can add live rock & a skimmer, for better filtration.> My other question is do I need to have more than one Mono?  I know they are a schooling fish but will this guy be alright by himself? <Yes, schooling fish are definitely happier & live longer (less stress=stronger immune system=longevity).  A school of 5-6 foot-long fish though, will require a 300+g tank, just for them.> And yes, I am aware that I will need to upgrade to a larger tank in the future as all of these fish get quite large! <Glad to hear you are aware of the adult sizes of these fish.  ~PP> Thanks Everyone!   Andy

Arius seemanni Tankmates?  2/14/07 Hello, <Hi Glenn, Pufferpunk here> I have seemingly happy (8 cm) Arius Seemanni living in a 120 US gallon tank with (right now) a 16,5 PPT. <HUH?> My questions: Is there room enough for more fish? <Your catfish is a schooling species, so more of the same, would be my 1st choice.  A beautiful sight--a school of these fish!> If so what about 3 or 4 Mono fish? <Monos grow to a foot & would require around 300g for a school of them.> If so Mono fish, which one would be the best in my situation Sebae or Argenteus? <Neither, IMO.  Monos not only get large (as does your fish) but they are extremely skittish & your cat is quite the swimmer--not exactly a calming effect for a mono.> If not Mono fish, do you have any suggestions (knowing that I want to go light marine). <I'd say get a couple more Arius seemanni.> What about Damselfish in light marine in company with 2 Arius Seemanni? <You catfish will eventually eat them & anything else they can fit into their large mouth.  ~PP> Thanks, Glenn

An Incompatible Mix - Monodactylus - 10/21/2006 How are you?   <Fair to middlin', and better all the time!> My name is Jason, I have a few questions.  I have read the multiple forums on monos <Monodactylus, I assume rather than the kissing disease.> and I haven't found the exact answer to my question.  I have an African cichlid tank with peacocks and labs only.   <Not compatible with Monos....> Would cichlid salt at least do some good for the two Monos I have in my tank?   <Not really.> I know they need marine conditions but I'm not able to do that nor brackish. <Then your best bet is to re-home the Monos.> What's the least amount of salt I can put in for them to give them at least some benefit over no salt at all?   <More than your cichlids could tolerate, I'm sure.> If I have to use sea salt, how much can Malawian cichlids stand (salt per gal etc.)?   <Not enough to be of consequence to the Monodactylus.> And can I use cichlid or aquarium salt rather than sea salt?  I have a 75g African tank ammonia 0 nitrate 20ppm <Higher than I'd like to see, but not harmful.> nitrite 0 and ph 7.9.  Believe it or not, the Monos are beating up my Africans <Of course they are.> rather than vice versa (which I expected).   <These animals really are incompatible.> Please help me out here and tell me a little secret or helpful hint to enable me to keep these Monos without having to change to saltwater.   <Sadly, there are none.> Hopefully my Africans can withstand the minimum that the Mono can get by with.   <Not in the long run.> Once again, thanks for all of your help. <All the best to you,  -Sabrina>

Keeping Monos with Freshwater Fish  4/14/06 Hello Bob, how are you?   <Bob is great, you've got Pufferpunk here today.> I wanted to put a few Monos in my 75gal and was wondering if the current fish I have in my tank will withstand brackish water?  The fish are as follows:  6 tiger barbs, 2 rainbow sharks and a clown loach.  I have read that they should be slowly acclimated to full concentration seawater as they age, but for now I wish to keep them in my FW tank (and later transfer them to my SW tank).  Can I do this with the fresh water selection of fish that I have? <None of your fish will appreciate salt of any kind, especially the amount you will need to even start out keeping Monos.  We're talking about at LEAST 1 cup of salt/5g for juveniles.  Also Monos grow to around a foot & are schooling fish (5-6).  This means at least a 300g tank for all of them.  ~PP> Thanks Keeping Monos in Unsuitable Conditions  3/6/06 Hey guys.   <Hi, Pufferpunk here> I looked over the forums attempting to find an exact answer to my question but I couldn't.  I want to keep monos but I prefer not to go the complete saltwater route.  Can I keep a few freshwater fish in a slight brackish environment?  And, I've read that monos lose their color as they age, does this mean they lose the yellow on their dorsal fin completely or does it still remain, just less? <Monos are schooling fish that require marine conditions as adults.  They grow to about a foot & will eventually require around a 300 gallon tank for a school of adults.  If you don't want to house them properly, then please consider a different species.  ~PP> Thanks J

Re: Adult Mono Coloration  3/6/06 Thanks, but you didn't fully answer my question.  What about the color changes as they get older?   <Personally, I have never seen a properly housed mono that grew to adult size, so I can't tell you if they keep their colors or not.  Most fish colors usually do get duller with age.> Don't understand why it would hurt a mono (if captive bred) to keep them in brackish water or fresh if they were raised in freshwater and that's all they knew? <Monos are not captive bred.  Even for a captive bred BW fish, it will compromise it's immune system, stunt the fish & shorten it's lifespan to keep in in conditions unsuitable for the fish.  ~PP> Thanks

Mono Library Tank  12/04/05 Good morning! I would like to set up a brackish water tank with monos in my library. But I also have a piano in there. Would the monos be affected by the noise of the piano? <Although the sound can be amplified by water, I would not worry too much. The fish may be stressed at first, but will likely acclimate to the sound in a short time. Be aware that these fish get big, like lots of exercise, and need to be in large groups... and plan the tank size accordingly. Best regards from Shanghai, John>

Growing Monos Up   12/28/05 Good afternoon!  I searched your sight for an answer first but could not find one.  I need to know the length of time it takes for the mono argenteus to reach its full size?  I spoke with employees of my LFS and was given two different answers (1 said 3 yrs, the other said 5).  Thanks in advance for your help. < I think they can reach full size in two years under perfect conditions. The first few months they are fresh to brackish and then go to brackish to full salt water. They get very big and I suspect that food and water quality are the limiting factors. Lots of protein with almost zero nitrogenous waste in a big tank with lots of circulation.-Chuck>  

Monos and Color Change  12/7/05 Hi! <Hello.> I read, on a website, that the Monodactylus argenteus loses its yellow coloring as it matures. How true is this? <Somewhat, some fish do change color pigmentation as they mature and most fish fade in color as they get larger and age. For any specimen, use a varied diet to maintain/ promote good looking pigmentation. Adam J.> 

Can I Make 'em Fit?  (Must be a Foolow-up)  12/9/05 Good morning! Could I put the monos in a 46 gallon if I only got 3? <These fish get big (> 6"), are full of energy, and will tend to be more aggressive toward each other in smaller quarters. I would give them at least 4' of swimming space -- 6' is better. Note that Monos also need heavy brackish or marine conditions. Best regards, John> 

Monos and Color Change  12/7/05 Hi! <Hello.> I read, on a website, that the Monodactylus argenteus loses its yellow coloring as it matures. How true is this? <Somewhat, some fish do change color pigmentation as they mature and most fish fade in color as they get larger and age. For any specimen, use a varied diet to maintain/ promote good looking pigmentation. Adam J.> 

Source water for brackish systems, Monos  9/1/05 Hey Bob how are you?  I had a question regarding conversion of saltwater to brackish water.  I have no choice but to use my tap water. <I use tap> From using tap water will I still have an algae spore problem like I did with saltwater, or will it be less algae in brackish water since there is less salt content?   <Could be less, the same or more...> Would you consider brackish water the same or less maintenance than saltwater? <Mmm, IMO/E, generally more... as most folks/systems are smaller than "average" than saltwater set-ups, less stable... people don't "on average" pay attention to brackish water quality... But these issues can be self-corrected...> And lastly, can I keep a mono in a freshwater setup for a lifetime if it was born in freshwater? <Uh, no... a "lifetime" will be much longer, healthier in brackish to marine for Monodactylids. Bob Fenner> Thanks, Jay

Monodactylus argenteus 07/01/05 Hi, <Liz> Is it common for monos to become darker at nighttime? <Yes> My mono is about 4" tall, but only recently I've noticed that a little after I turn off the aquarium light, the Mono's yellow dorsal fin turns gray and many times is pulled down and back.  In addition, the eyes become cloudy, and the mono is usually hiding out behind a rock.  During the daytime, the mono is bright and the fins are yellow, however.  I've often done 1/4 tank water changes because I thought something was wrong with the water quality (and the Mono's fins turn yellow usually within 20-30 minutes of this, but is it just because the light is on?), <Mainly... but like most fishes, these animals do have a sense of time, diurnal rhythm> but it's been occurring so often (every 2-3 days or sometimes more frequently) that I don't think it's a water problem.  The other fish in the tank (brackish water, with a puffer, and some freshwater fish like bloodfins and tiger barbs and a rosy barb) are always doing fine when I find the mono in this state.  I'd appreciate any help you can give me! Thanks, Liz <Nights are a dangerous time in the wild... the darkening of color is thought to aid in disguise, avoidance of predators. Nothing wrong here. Bob Fenner> Color Changes in Mono Hi. I'll try to keep it short. I have a 75 gal. tank. Varied assortment of fish, and I know that monos are brackish. There are 4( Sebaes). The rest: gouramis a leopard, a red finned black shark, scissor tails, and a few others that I cant remember their names. No matter. They all get along well and they all seem healthy. My query is about one mono. He is the largest in the tank (4 in). and he is dark. I cant imagine why. He and his brothers were introduced about January, and they are growing! Here are the vitals:  nitrate 40 nitrite . 5 hardness 150 alkalinity 120 pH 7.8 temperature around 74/ 80 (no heater) I don't have a hydrometer, so I can't say, but did put in a full cup of sea salt for the 75 gals, adjusting for sand and rocks, perhaps a bit more. The thing that gets me is that all the fish seem fine. They all do what they are supposed to do. Swim, eat, chase about a bit, and look pretty. I couldn't ask for more. There is no violence. The dark mono is the king of the tank, and eats like there is no end. He picks on his brothers but it is over in a few seconds: there is plenty of room. Nobody hides. I have ideal well water, a bit on the hard side. I'm stumped. He (or she )? has only shown this darkness in the last week or so, and the first thing was a 45% water change. Nope. pH was a bit alkaline, adjusted down a bit. Nope That's it. I cant think of anything else. I am not losing any sleep over this, but I am concerned. Any ideas? Thank you Paul  <<Sebae monos get darker as they mature. What you are seeing is that your dominant animal is beginning to show this pattern at times. As they get older others may get dark also. During spawning both sexes will have this colour. Had you said that the lowest ranking animal was dark in colour and not eating it would have been a sign of stress or illness, unfortunately the colour change in monos is the same in that situation. Your dominant fish may get more aggressive as he gets older, so be sure to watch in case he decides to chase his conspecifics (other monos) too much. For now, I would not worry about it. Good Luck, Oliver >>

Mono Follow-up Hi Oliver, Whew! That's a relief. I feel much better. Now, as a curiosity, about how  large would you expect monos to get in my 75 gallon tank? Thanks again Paul <<If you do regular water changes they should get to their maximum size, around 8" for sebae. AT that point your tank may be a bit small, but it could work if they turn out to be not too aggressive.  O. >> 

Salty Monos Eating Salad I have just added 2 Monos to my 150 gallon salt tank. My first question is about their diet. I saw all of the foods that they will eat and like to eat but they have been eating at the Seaweed Salad that I have clipped to my tank for the Yellow Tang. Is this ok for them or is it a sign that they need more meals during the day or larger meals during the day? Thanks Dan <<Or, it means that they REALLY like the Seaweed Salad, too. Dan, there is no problem whatsoever with fishes eating outside whatever pre-determined parameters humans have given them. What is actually THE MOST important aspect of feeding just about anything is variety. The Seaweed Salad is likely offering them this variety.  Also, these tend to be very active fishes, especially once they hit "size". Know that high vegetable content with these fish means they're going to be "poop machines", don't take this lightly. In my opinion, feeding is determined by the fishes' appearance. With Monos it's quite easy to tell when they're healthy and when they're not. Shiny skin/scales (and I do mean SHINY, like silver), active, only slightly rounded when viewed head-on. What you DON'T want to see are sunken areas along the dorsal ridge (slightly rounded to flat in appearance when viewed head-on), or behind the eyes. Bulging abdomens are a bit much on the fatness side. Do watch your water parameters, these fish can be demanding in terms of bioload. Marina>> 

Salty Monos Eating Salad - II Thank you for your fast and informative reply I will take the words to heart. Don't need to crank up the poop machines. Dan <<Heh, you're very welcome. Marina>>

Mono with white Spots 3/15/04 Hello, <Hi, Pufferpunk here> I just noticed today that my mono has little white spots on it fins. Is this ich? How to you treat this? Do I quarantine him? I've got 2 GSPs in the aquarium with him, no live plants. I'm actually going to do a water change today (Monday). <Water changes are always good for the health of your fish (I do 50% weekly on all my tanks). Are your fish in brackish water? FW ich cannot stand the salinities that GSPs & monos require. I also would not keep a single mono. It is a very skittish, schooling species, that will grow to a foot. I would not keep a mono with aggressive fin biters such as puffers, either. Since you can't return the mono while it's sick, raise the temp to 86 & keep up with water changes & salt. Get marine salt & a hydrometer & start raising the SG (specific gravity, a measurement of salt with a hydrometer) up to 1.002 & then to 1.004 in 3 more days. After that, raise it no more than .002/weekly water change. For future reference, you need to use proper capitalization & punctuation. We post these letters & responses in our FAQs for all to see & I have to correct that before we can do that & it takes up much of my time. ~PP>

Monodactylus 3/14/05 Hi, my Monodactylus argenteus just recently (in the past 2-3 days) has a reddish coloration and possibly a little swollen spot above its mouth. The water I keep him in is fine, could this possibly be some kind of bacterial infection/how do you treat this? <without a close-up photo or much better description... it is difficult for us to diagnose sight-unseen. But yes, it may be a bacterial infection, It could be a wound ripe for such infection. If the fish is still eating well, get some medicated fish food and feed it in several small daily feedings for the next several days assuming the matter does not get worse. Be prepared though to medicate (ideally in a separate QT tank - bare-bottomed) with a Nitrofurazone-Furazolidone based medication such as Jungle brand "Fungus Eliminator"> Also, I've had him for about 2 weeks now and he's in the tank with 2 other monos which are fine, they all eat well and overall look great including the one with the spot above the mouth. He doesn't seem sick or anything and I just don't know what to do, any suggestions would be great and much appreciated, thanks. <do check with your local fish store for medicated flake food (antibiotics in it). And keep that medicine on hand as a good first choice for such infection sin the future. Best of luck, Anthony> 

INSANE LFS Employee!!! 4/20/04 -Hi Pufferpunk, I thank you once again for your help. You simply can't imagine how mad I am with the irresponsible seller. He's the one who helped me set up my aquarium 3 weeks ago and has NEVER mentioned that those bats are marine!!!! He is a HORRIBLE HORRIBLE MAN!! I've lost one and that has been a mystery. How the other 2 survived I have no idea. (my loaches are healthy, active and eating fine thank goodness)  <How big is the tank? As I told you, those fish are going to get very large & if your tank is only 3 weeks old, it can't possibly be cycled yet.> Anyway I brought them back to the shop just now as I'm ill-equipped for marine fishes, and he insists that if I had added some salt, the bats will be fine, and that the loaches can tolerate salt as well (can they?). <Nope, loaches are soft water fish, the opposite of salt-loving fish & don't like salt of any kind.> Later he said his bat fishes WERE marine but were 'converted' into freshwater ones. <You mean "forced" into tolerating FW.> I've clicked on the site you sent me and I don't see my bats there, but they do resemble Platax boersi but are much smaller with shorter fins. <<Likely monodactylids. RMF>> Now I realize I should have taken a picture of those bats before returning them so you can confirm if they are a 'converted' species (I really have no idea what that jerk was jabbering about). I've tried surfing around but I've yet to find a picture or info of my bats. <There is no such thing as successfully converting a SW fish to FW. Even in BW they will suffer compromised immune systems, more diseases & shorter lives.>  I did what you told me and brought up the puffer incident (he lifting it out of the water and making it puff), and he went mad and scooped up all his poor puffers to show that there's nothing wrong with it. I'm never going back again, a fish killer is what he is. <That guy's insane! Is he the owner of the shop? You really need to talk to the owner.> Thank you for listening to my fish woes.. your help has distressed me a lot really! Have a great day. <Good luck with your fish. Make sure to give the owner of that shop a piece of my mind too! ~PP>

He's Got Mono - Monodactylus Sebae - 01/18/2005 Hello <Hello.> I have a Mono Sebae that has become quite large and has always been happy. He has his favorite food and although they are very wary when you stand next to the tank and drop in the food, the moment you walk away, he eats at all in a flash. The tank he was in had no substrate at all, but I found that rather cruel, so very slowly have started to add washed sand to the bottom. What I have noticed is now he doesn't seem to go crazy for food anymore. I am on the verge of taking out all the sand again to get him back to normal, but I still need to know why this would cause his behavior to change. <Chances are, the change in substrate is not what has brought about these issues, but perhaps a change in water quality....  With so very little information about your system, there's really nothing for us to go on to discern what might be the problem.  A few questions:  How large is the tank?  How large is the mono?  Are there any other monos with him (keep in mind, this is a schooling fish)?  Is he in a freshwater, brackish, or marine environment?  This is one of the many fishes offered for sale in freshwater aquaria that really seem to require increasingly brackish to marine water as they grow.  Do you test the water for ammonia, nitrite, and nitrate?  What are the readings on those tests?  If you do not have test kits, take a sample of your water to your local fish store to have them test it for you.  What kind of sand did you add - rather, where did you get it?  How did you wash it?> Regards,  Andrew <Please do get back to us....  With so little information on you/your system, there is very little we can tell you.  Wishing you well,  -Sabrina>

He's Got Mono - Monodactylus sebae - 01/26/2005 Hello. <Hi, again!> Thanks for replying to my question. <You bet. And, er, please accept my apologies for the delay in this reply.> The problem ended up being that the sand I had purchased had contained something and stupid me had not cleaned the sand before I had put it in the tank. The only reason I didn't clean the sand first was that I had already used half the sand in another tank, let it cycle for two weeks, and I then put fish in, which are absolutely loving it, so I had no idea that the sand had contaminants in it. <Mm, I still would definitely not rule out other environmental causes - please do be testing for ammonia, nitrite, and nitrate, and keep in mind that Monodactylus require increasingly brackish water as they age for best health. You may know that stuff already, but I'd rather repeat information you already know than skip over it, since I do not know you or your experience.> Anyways, my Mono has passed on, and I'm very upset as it was one of my favourite fish.  <I am very, very sorry to hear of this. They are tremendous creatures.> Thanks again for showing an interest in other peoples problem. I really appreciate it. <And thank you very much for the kind words.... We are, as always, glad to be of service.> Regards, Andrew <Wishing you and any Monodactylus in your future well, -Sabrina>

Monodactylus in a reef tank? 8/31/04 I have a reef tank with large stony and soft corals will these fish bother them? <The Mono's are probably fairly safe, but since they are known to occasionally eat Aiptasia anemones, they may sample other cnidarians as well.  I would keep an eye on them, but not sweat it too much.  Best Regards.  AdamC.> Brackish puffer loss, monos Ananda, <This is Pufferpunk, I'll be answering your puffer questions.>        This is  Chris again, I have sent you e-mails before asking questions about my Fahaka puffer. Well, after about two and a half years and a very rough final few months, my puffer finally gave in and died a few weeks ago.   <So sorry about your Fahaka!> I am sure you can relate to how it feels. I have been trying to put my mind at ease lately, just wondering if there was something I could do. The person at the pet store <Yeah, you can stop listening to those folks!> said that two and a half years is a pretty long time to live and he also could not believe that such an aggressive fish could live for so long with the other fish I have. Is 2 1/2 years a long time? <They can live up to around 20 years & grow over 16"> Have you ever heard of a fish such as the puffer eating for a few weeks and then not eating for a few weeks and then eating again? <Could have had internal parasites.  Most wild-caught fish come in w/them, including my Fahaka (now over 12").  Fish can live a long time w/them & just loose the battle.  Discomed is what I use to treat all my new puffers.  Please research these precious fish next time.  Any fish you're not familiar w/needs some research before buying!> I still to this day cannot figure out what was wrong with the puffer towards the end. <You need to be aware that these fish need around 125g tank as an adult.  They also need a wide variety of foods>        Now what I have left is a Labidochromis a mono and a pleco, not very exciting. The Labidochromis I have had for almost the same amount of time that I have had the puffer. The mono I am worried about because I have read and you also told me that as the approach maturity, Mono's need the water to be saltier than when they were younger. I read in one book, and I cant see how this is true, that mature Mono's need 1-2 tbls. spoons of salt added to ever 1.3 gallons of water, to me that seems like way too much salt. I don't know if it because of the lack of salt in the tank, but the mono has a dark gray tint to its scales where it should normally be silver. Right now, when I do a water change, I will put about 1 1/2 tbls. spoons of salt to every 5 gallons. Do you think that is too much, too little or just right. <The mono should be in a SG (specific gravity of around 1.008 by now.  It takes a cup of salt/5gal to raise the SG .005.  You need a hydrometer to measure this.>  I have to worry about putting to much salt in because of the pleco. I think I need a little advice in this area. <Plecos don't like salt!  Either set up a separate BW tank or find a new home for your FW or BW fish.  You cannot keep them together!> I was going to get a larger tank, right now I have a 20 gal. After my favorite fish died, I just don't have it in me right now to replace the puffer and ad more fish to the existing tank nor do I feel like starting over with a larger one, which I know eventually would like to do. What advice can you give me about moving on..? <Decide if you want a FW or BW tank & do research on all the fish you are thinking of getting.  Compatibility, water preferences, aggression (Fahaka's will eventually kill any tankmates, except maybe a pleco, depending on the Fahaka), adult size.>        I would greatly appreciate it if you could write me back so I can get back on track and have a better direction on what I want to do and what I need to do to make the lives of my remaining fish a good one. Thank you for your time,        Chris <Good luck with your fish--Pufferpunk>

Brackish puffer loss, monos, Ananda's responses (12/01/03) Ananda, <Hi!> This is Chris again, I have sent you e-mails before asking questions about my Fahaka puffer. Well, after about two and a half years and a very rough final few months, my puffer finally gave in and died a few weeks ago. <Sorry to hear that.> I am sure you can relate to how it feels. <Yup.> I have been trying to put my mind at ease lately, just wondering if there was something I could do. The person at the pet store said that two and a half years is a pretty long time to live and he also could not believe that such an aggressive fish could live for so long with the other fish I have. Is 2 1/2 years a long time? Have you ever heard of a fish such as the puffer eating for a few weeks and then not eating for a few weeks and then eating again? I still to this day cannot figure out what was wrong with the puffer towards the end. <I'm going to leave a copy of this in Pufferpunk's box -- she has a Fahaka and so knows more about them than I do.> Now what I have left is a Labidochromis a mono and a pleco, not very exciting. The Labidochromis I have had for almost the same amount of time that I have had the puffer. The mono I am worried about because I have read and you also told me that as the approach maturity, Mono's need the water to be saltier than when they were younger. I read in one book, and I cant see how this is true, that mature Mono's need 1-2 tbls. spoons of salt added to ever 1.3 gallons of water, to me that seems like way too much salt. <Mature monos should have far more fish than that -- about 1/2 cup per gallon, or a bit more to get it up to full-strength saltwater. They are brackish fish that live in the ocean as adults.> I don't know if it because of the lack of salt in the tank, but the mono has a dark gray tint to its scales where it should normally be silver. <Could definitely be insufficient salt.> Right now, when I do a water change, I will put about 1 1/2 tbls. spoons of salt to every 5 gallons. Do you think that is too much, too little or just right. <Nowhere near enough for the mono, okay for the other fish -- though I am still concerned about whether or not you have good water chemistry for the Labidochromis.> I have to worry about putting to much salt in because of the pleco. I think I need a little advice in this area. <I would move the mono to another tank and turn the existing tank into a cichlid tank.> I was going to get a larger tank, right now I have a 20 gal. <The mono will need a much larger tank as it gets older. So will the pleco.> After my favorite fish died, I just don't have it in me right now to replace the puffer and ad more fish to the existing tank nor do I feel like starting over with a larger one, which I know eventually would like to do. <Yup, I understand that.> What advice can you give me about moving on..? <Take care of your existing fish, which means get a second tank and split them up...starting a second tank is much easier than starting the first tank.> I would greatly appreciate it if you could write me back so I can get back on track and have a better direction on what I want to do and what I need to do to make the lives of my remaining fish a good one. <Asking questions is a good start. Please do check out our forums at http://wetwebfotos.com/talk, to.> Thank you for your time, Chris <You're welcome. --Ananda>

- Acclimating Mollies to Saltwater, Doh! - J- Thanks so much for responding. <My pleasure.> I just wanted to make sure though -- I'm talking about a mono (Monodactylus argenteus) - not mollies. <Oh, I am so silly... my apologies.> Does what you wrote still apply? <Sure, in fact you can go a little faster if you want. These fish are actually saltwater fish.> Again, thanks for your time. Nicole <Cheers, J -- >

Sick Monodactylus argenteus Hi, I was referred here by a member from MyFishTank.net.   <Hi! Ananda here tonight...> The picture of my sick Monodactylus argenteus is in this link http://members.shaw.ca/alistair4/Mono.JPG.   <Hmmm... do you have a photo with a sharper focus?> It was only recently this fish got this disease.  I've kept these guys for over 4 months and it was only recently they started appearing like this. <Have you done anything differently lately? Added anything to your tank?> It looks like fungus but does not have the cotton description.   <More description might help... is it just whitish and flat? or whitish and lumpy but not cottony?> I've had 4 monos at relatively the same size (1-1.5") and 2 of them have contracted this same disease and passed away.  The one in the picture is the 3rd sick one and if this passes away, I'm not sure whether I will continue with monos.   <They do get large and require full-strength saltwater when they mature....> So far I've used MelaFix.   <Useful in aiding fin regrowth, and possibly preventing opportunistic infections, but not likely to help with a fungus... I would increase the salinity a bit. True funguses are quite rare in saltwater fish.> The pH is around 7-7.5, ammonia is at zero.   <That's far to broad a range for pH. Your pH should be steady within 0.2 points. Also, do check your nitrites/nitrates. What specific gravity are you running at?> The sick mono is still eating and not isolating itself from the others.   <That's a food sign. You might consider adding a good multi-vitamin to its food to help it keep its strength up.> I will try to take a better picture if you want, but the fish is very fast and I don't want to over stress it.  Any comments are welcomed. <I would put the affected fish in a hospital tank to reduce the possibility of it infecting other fish. Then you can start treatment, perhaps beginning with a moderate increase in specific gravity. Do email back and let's see if we can beat this thing. --Ananda> Thank you for taking your time to read this e-mail Alistair Leung

Marine Tank Stocking Do you think that a 55 gallon marine tank can hold any more fish if it has 5 Monodactylus argenteus in it? <These guys get pretty big, a good bit over 6" each.> Could you suggest and more species? I am interested in triggers and butterflies, as well as some gobies and inverts. Thanks. <Do see here for further information http://www.wetwebmedia.com/monos.htm -Steven Pro>

Can Monos be placed with African Cichlids I have one Mono right now. I don't want to have more then two so I am considering putting my only Mono in with four African Cichlids who are small. Let me know if you can if this would possibly work or not. Thanx, Steve <Temperament, smarts and speed-wise this might well work out. What species of "Africans" in how big a system? If easygoing types, at least a forty gallon, good chances of being okay. Bob Fenner>

Fingerfish in the reef tank? Hey Bob, I saw some small 1.5-2" Fingerfish (Monodactylidae) at my LFS. I was wondering if they are compatible within a reef tank?  <Yes... if acclimated to full seawater conditions> What do they eat? How big do they get? Solitary or schooling fish within a 60G? All the info on this fish would be great help. <Ah, please see the coverage of this species, family on our site here: http://www.wetwebmedia.com/monos.htm Bob Fenner> Jackie

Monos I have reviewed your information on monos on the WetWebMedia website. I was wondering if you had ever heard of anyone keeping monos in a reef tank?  <Yes, have done this and seen this done> Will they bother inverts? <Minimally. Don't eat cnidarians... maybe nibble sponge life, ascidians to some extent... and definitely will chew algae, micro- and macro-.> thanks, Brian Lory <Be chatting. Bob Fenner, who is treating himself this afternoon and next and writing more brackish pieces.>

Mono Disease Robert, I have a Mono that has recently come down with a disease that I've never seen and am unsure how to treat. The fish exhibits no signs of a problem other than general appearance. His swimming and feeding habits are normal however he does seem to be staying higher in the tank than usual. I would greatly appreciate any help or suggestions that you may have. I have also attached a pic. showing the problem in question Thank you, Brian E. Nelson <Mmm does look like some sort of bacterial, possibly fungal involvement on the side of this fish... I take it, this injury site is one-sided. Likely consequent a physical trauma (have encountered this many times).... hence secondary. I might try feeding an antibiotic laced food (for infectious disease) here. These are made by HBH, Tetra, a few others, or you can make your own. Detailed somewhat here on our site: http://wetwebmedia.com/holedispnd.htm Do you use salt in your Mono's tank? I might increase the specific gravity a few thousandths here... over as many days... should favor the fish, disfavor the infection. Bob Fenner>

Re: Mono Disease Bob, Thank you very much for your input. I do use Brackish salt in the tank with a S.P of 1.005. <Do raise this up to 1.010... stipulated the other livestock can take this... over the next few days> and Temp. of 82F, and general hardness around 400. I generally use R.O. water but do occasionally top up with well water. I did try raising the salinity slightly and am presently treating with Melafix (Tea extract). This infection is only on one side and appeared over night. Would/could a temperature change be helpful in treating? <Maybe... but could add more stress than it's worth at this point... depending on etiology/root causes could call for either raising/lowering...> Approximately 6 months ago the Mono did show a sign of Pop Eye which was treated. Otherwise his health has been no problem. The others in the tank don't seem to show any visible signs either. I will check out the site and look into treated food. Thanks again for your opinion. Brian <Real good... and wrote a couple more installments for the "Brackish Water" Index: http://wetwebmedia.com/brackish.htm for same (WWM) a few weeks ago and drafted a couple more during a trip last week... will key and place soon. Be chatting. Bob Fenner>

Mono Hi there My tank currently is in 1.010, and I want to add Monodactylus argenteus into my tank, but the Monodactylus argenteus was in 1.022 full marine b4. Is that possible to do that? <Absolutely... and though these "Moonfish" move readily between this range of "saltiness" in the wild with ease,  I would take your time, in a separate "quarantine" tank set-up, adding some water from the new system to the  Q tank about every week, moving the spg about a thousandth or two toward the new density... acclimating the new fish to the 1.010 spg over a couple of months. Bob Fenner>

I just recently discovered FFE and Q&A and am fascinated by both. So much so I couldn't order your book quickly enough. I'll be moving soon and setting up a 130 gallon tank plus a hospital tank. I'm out of touch with the hobby in some ways because I've had a 55 with Monos (in 1.020) for the last 8 years. I'm going with fish only, but the live rock sounds too good to pass up. Could you tell me how much, when to add, how to stack it and anything else I need to know? Also is it good indefinably or does it have to be exchanged at some point. By the way, the new tank will have a variety of fish. >> Ah, Monos, Moonfish, Fingerfishes... I have some gorgeous pix of schooling M. argenteus from the Seychelles... Yes to the live rock... there are many things to state re its proper handling/curing and any amount, arrangement is fine... The rock actually doesn't last forever, and parts should be supplanted or added to every year or so. My more detailed notes on processing this wild product can be found in articles on Live Rock archived at www.wetwebmedia.com and FFExpress new Archive section... Bob Fenner