Tank Size For Monos

[Mønøs]

Hi I'm new to these forums. I presently i have a single Sebae Mono who is housed in a 45 gallon tall (48 long 12 wide and 18 tall). I already know that a 45 gallon will in no way supply for the future needs of my fish but i have no idea what size tank would work to house him.

Also i have recently found out that Monos are in fact schooling fish. Of course i plan on getting him buddies. Would a Mono (Monodactylus argenteus) mix OK with a Sebae Mono? If i plan on adding more Monos what would be a good number (i have heard the odd numbers are best), and what size tank would be enough to accommodate them for life?

Mine as well post a shot of my tank

 

[HX67]

Hi, another hangaround member opening his career on FF.

I have been trying to find an active brackish forum for awhile. Not very easy.

I'm not sure if I can give a solid answer to your questions, but I'm open for discussion based on my experience. I have a mixed sebae-argenteus school of 4 + 5. They seem to be doing great together. They usually school together, sometimes divided into groups of their own kind.
I have had them in a 1000 liter (250 gal) tank for a year or so.
Other tankmates are a few puffers and a G. tile moray.

There is a clear dominant for the whole group, the largest of the sebaes. It is not aggressive, but shows it's dominance regularly. The others don't challenge it. There is no notable aggression between species.
The fish are about 12-15 cm at the moment.

The largest mono I have seen was almost 30 cm tall. I'm thinking that my 1000 liter tank will not be big enough for the nine of them if they grow up to that...

So hi and thanks for a nice forum, people.

Here's a pic showing the atmosphere... well, rather aquosphere of my tank. Live red mangrove rooting and synthetig stone/root decoration present.

 

[nmonks]

Monos certainly are schooling fish in the wild -- but in captivity it's much less consistent! While I've had success keeping mixed groups of monos, scats and archerfish, Frank Schaefer (author of the Aqualog book on brackish fish) maintains he usually ends up with a single dominant pair of monos per tank. So if your singleton is well adjusted, shows the right colours, is happily feeding, and doesn't seem nervous, I personally wouldn't worry too much.

Adding a scat in particular may be a good idea: these two species group together in the wild, and in aquaria get along extremely well. Mixing two different mono species usually works well too. So either approach could be recommended.

Maximum size is difficult to say. In theory, adult Monodactylus argenteus get to about 20-30 cm in length. Such sizes are extremely rare in home aquaria, with around 15 cm being typical. Further complicating matters is that a third mono species, Monodactylus kottelati, is seemingly imported quite widely but never identified as such. It is a "dwarf" species that is said to get to only about 8 cm in length in the wild (perhaps more in captivity?). Telling M. argenteus and M. kottelati apart is difficult, but I've tried to explain on my brackish FAQ and in my book.

By the way, HX67, your tank looks great!

Cheers, Neale


* Specifically three Monodactylus argenteus, one M. sebae, one Selenotoca sp., and one Toxotes jaculatrix.

 

[Mønøs]

Monos certainly are schooling fish in the wild -- but in captivity it's much less consistent! While I've had success keeping mixed groups of monos, scats and archerfish, Frank Schaefer (author of the Aqualog book on brackish fish) maintains he usually ends up with a single dominant pair of monos per tank. So if your singleton is well adjusted, shows the right colours, is happily feeding, and doesn't seem nervous, I personally wouldn't worry too much.

Adding a scat in particular may be a good idea: these two species group together in the wild, and in aquaria get along extremely well. Mixing two different mono species usually works well too. So either approach could be recommended.

Maximum size is difficult to say. In theory, adult Monodactylus argenteus get to about 20-30 cm in length. Such sizes are extremely rare in home aquaria, with around 15 cm being typical. Further complicating matters is that a third mono species, Monodactylus kottelati, is seemingly imported quite widely but never identified as such. It is a "dwarf" species that is said to get to only about 8 cm in length in the wild (perhaps more in captivity?). Telling M. argenteus and M. kottelati apart is difficult, but I've tried to explain on my brackish FAQ and in my book.

By the way, HX67, your tank looks great!

Cheers, Neale

LOL thats your FAQ. I've been using that thing for ages! I even have it bookmarked.

My mono looks fine (showing silver and only turns dark when asleep or disturbed). I did in the past have and Archer in there (according to your faq it was Toxotes jaculatrix) but the mono sadly killed him . I think if i could choose i would increase the number of monos to 3 (which from your post sounds that it would be fine) this would be leave me with enough money to buy a good piece of driftwood (the old stuff i collected rotted).

My Maximum dimensions i would be allowed for the tank would be something like 5x2x2

Do three monos fill a tank that big? Im fairly good at stocking small fish but with large fish i'm dumbfounded. If it is more than enough space what other fish (besides scat) would work fine with them?

Thanks

 

[nmonks]

Three monos would be fine in a tank this size, or really anything upwards of, say, 200 litres/50 gallons. The main thing is that the front of the tank should measure a good 120 cm/4 feet in length so they have some decent swimming space. Strong water current, so they can "tread water", makes all the difference. Submersible powerheads of the sort used in marine tanks are a cheap way to "stretch" a small tank and make it feel more roomy to the fish, by giving them strong water currents to swim against.

Monos work best with each other, with either scat genus (Selenotoca is my particular favourite because of its amazing looks), green chromides (Etroplus suratensis), orange chromides, archers, violet gobies, sleeper gobies (Butis butis, Dormitator, etc), and really most anything too big to be eaten. They are quite phlegmatic, and often kept with predatory fish in public aquaria, even sharks! If the salinity is reasonably high (SG 1.010+) then some high end brackish to marine species are definite options, including Arothron spp. and things like stripeys (Microcanthus strigatus), an infrequently traded but gettable butterflyfish-like schooling omnivore. They also work great with brackish/marine catfish of all types, including ariids, bagrids and plotosids. Of the species in the trade, Mystus gulio would be the one to make an effort to obtain. It isn't too big (around 15-20 cm seems typical for the Indian subspecies).

Cheers, Neale

My Maximum dimensions i would be allowed for the tank would be something like 5x2x2

Do three monos fill a tank that big? Im fairly good at stocking small fish but with large fish i'm dumbfounded. If it is more than enough space what other fish (besides scat) would work fine with them?

 

[HX67]

By the way, HX67, your tank looks great!

Thanks, Neale. The pic I meant to link, was the one with the monos:

Btw, thanks and a deep bow for your brackish pages. They are phenomenal.

Three monos would be fine in a tank this size, or really anything upwards of, say, 200 litres/50 gallons.

It may be that I don't see how small they stay in the end, but I would give three monos more than 200 liters.
Even if they stayed at discushis size, being much more active fish, I would give them more room. At least 300-400. But that's just me. And I'm afraid that they outgrow my 1000 l tank.

 

[nmonks]

I agree; monos will use up every inch of space in any aquarium. The bigger the tank, the better! I kept mine in a ~200 gallon tank and they constantly swum about, from one end to the other and back again. On the other hand, even there they never got more than 15 cm/6 inches in length.

But my point is that they're not obviously "happier" in big tanks compared to medium sized ones: I get the impression that ANY tank is too small for them compared to the sea, and the best you can do is provide sufficient space and water quality that they live a good life. You're probably right that 200 litres would be a little tight, and certainly 300+ litres would at least give monos a bit more space to move about. Does rather depend on the species though: if you're lucky enough to get some M. kottelati, a 200 litre system wouldn't be too bad at all.

Cheers, Neale

It may be that I don't see how small they stay in the end, but I would give three monos more than 200 liters.
Even if they stayed at discushis size, being much more active fish, I would give them more room. At least 300-400. But that's just me. And I'm afraid that they outgrow my 1000 l tank.

 

[seffieuk]

If you like Neale's FAQ you should defo by his book, it is awsome

Seffie x

 

[monoducze]

Hi, I'm new to these forums. And sorry for my English
I have idea of brackish tank with Monodactylus argenteus. Aquarium 576L (160x60x60cm). I'm thinking about school of 7 argenteus (only this species). Substrate will be fine sand (about 12cm - DSB), decorate with limestone and roots, without plants. Filtration: external 1700l/h with JBL CP120 as a mechanical prefiltr.

This tank will be sufficient for them? 7 it is a good number of monos or too much?

Michal-Poland