Denison Barbs/Roseline sharks with Arowana

[jjohnwm]

I think the answer to the question is that it depends.
It depends on type :Silver arrowana get on with tank mates much better than Jardoni do.
It depends on the character of the fish: even predatory fish come in various types from really aggressive to really laid back
It depends on the size of the fish: my 12” silver lives in a 6x2x2 with a whole host of tank mates from 2” skunk botia, 5” filament barbs and 12” tyre track eels all quite happily.
It depends on the setup: my tanks are all natural looking with plenty of hiding places, floating plants etc. To keep the fish happy and “entertained”. A bare box becomes a bore and everyone is always on show.
It depends on proper and regular feeding
It depends how long for: obviously my aro can’t stay in a 6x2 forever so he will move to my pond where my 2ft red tail catfish and 28” Wykii live with 8” synodontis, 10” pims and 12” Jaguar cichlids and have done for around 2 years now.
The above goes for many “predatory” fish in my opinion and there isn’t a one answer fits all, simply because there isn’t a one situation fits all.
maybe 2 years is not long enough to have been watching for someone to get eaten....... I don’t know .......

All of these variables would play a part, no question about it. I would ask if your arowana, wykii and RTC have never, ever eaten a tankmate? If not that would be quite amazing...although still not a justification for recommending that this combination be attempted. For it to be considered successful, it isn't enough for the small fish to merely not be eaten; the inhabitants would need to co-exist comfortably, with enough food for all, enough space for all, no attempted swallowing incidents that result in the death of one or both fish, etc.

There are people who have survived sky-diving jumps during which the parachute failed to open; there are people who have been struck by lightning and suffered no permanent ill effects; there are people who have been mauled by grizzlies, attacked by sharks, struck by buses and suffered any number of other extremely dangerous accidents, and yet have survived relatively unscathed. Does that mean if someone asks about one of these experiences that the answer should be "No problem, go ahead...that should be fine"?

But, since we are apparently grasping at straws to make the claim that the combination suggested by the OP will work, let's do so:

If you have a tank set up with plenty of cover and hiding places for the little guys, but without impinging too greatly on the already limited swimming space that any aquarium provides for a large predator...and if you keep the predators always well fed, never missing a feeding long enough for them to get too peckish...and if the small tankmates are fast-swimming agile fish...and if your arowana happens to be a particularly non-aggressive feeder with a relatively low prey drive...then it is conceivable that these fish could co-exist in the same tank. Simply provide the elements that you can, hope and pray furiously for those over which you have no control, and then sit back and relax.

Or, you could simply examine the odds, accept the reasonable assertion that keeping large predators rogether with small potential feeders in close confinement is unlikely to work out well for the little guys in the long run, and move on.

 

[Fishman Dave]

All of these variables would play a part, no question about it. I would ask if your arowana, wykii and RTC have never, ever eaten a tankmate?

To date, the red tail and arro haven’t eaten anything, although when younger the Wykii would have taken my hand off in a 6ft tank and would have torn tank mates to shreds
but now in 1400ukg pond she is much more relaxed.
However, I have also owned an 18” redtail that lived with a 12” arrowana from birth for over a year in a 6x 2 only to wake up one morning with the tail of the arro sticking out of his mouth.

although still not a justification for recommending that this combination be attempted

im not naive, not stupid, nor irresponsible, BUT as I thought I was saying, it’s not as simple as saying No it will never work , or Yes it will always work.

Not sure who’s supposed to be clutching at straws as I certainly didn’t say that the combination should definitely be attempted.
Equally, nor did I say it definitely wouldn’t work.

Just out of curiosity, how do we decide what is a predator and what isn’t ?
An arrowana with a barb won’t work because the arrowana is a predator?! yet so many people keep neons with angelfish and this is ok?
Is an angelfish not a predator?
Will all angelfish eat the neons?
So how do we decide which fish will be ok with the angelfish if neons never will with any angelfish?
Maybe we ask the opinions of others and if all else fails, unfortunately we have to try them, and hopefully learn by our mistakes or our successes so we might pass this on to others.

 

[jjohnwm]

...im not naive, not stupid, nor irresponsible, BUT as I thought I was saying, it’s not as simple as saying No it will never work , or Yes it will always work...

Didn't mean to imply that, and I apologize if it came across that way.

The angelfish/neon thing (or variations thereof) is done a lot, and many or most of those times it ends up poorly, but it isn't quite as extreme as examples where the larger fish is an arowana. I agree that virtually all the fish we keep are, to a greater or lesser extent, predators...i.e. they eat smaller living animals when given the chance. A guppy eating brine shrimp is still a predator, we just don't tend to think of it in that light...but as soon as the predator starts eating things we don't want him to eat that the weeping and wailing and wringing of hands begins...and I think we agree that by anyone's standards, an arowana is a predator.

You're right, there are no absolutes; each case must be examined individually. To the OP I continue to suggest that this sounds like a poor idea, not necessarily doomed to failure...but nevertheless very likely to fail. If you continue to pursue it, perhaps choosing a less expensive feeder fish...er, sorry, dither fish...like Giant Danios or something similar, might soften the blow if it doesn't work out.

 

[andyroo]

I like this idea, to have "big" and then pretty little dithers for colour. My issue with denison's would be that they're mid-size, so 'on the menu' whereas smaller tetras, danios etc. might fall below, become background-noise to the larger pred. There'd be species options for self-replacing/breeding including ongoing replacement; nothing wild-caught, that'd be a little irresponsible (tree-hugger me). Den's are also maybe a little costly for this. Having said that, have plenty of space, current & hides/plants and you might get away with it. Start with a bigger population of barbs with space &habitat & see if you can get a self-replacing population. Keep the aro on bugs & surface-stuff as long as you can, try to keep her looking down for dinner. Surface plants to keep attention upwards. Keep us posted.

Apologies if this has been said already.

 

[Magnus_Bane]

To date, the red tail and arro haven’t eaten anything, although when younger the Wykii would have taken my hand off in a 6ft tank and would have torn tank mates to shreds
but now in 1400ukg pond she is much more relaxed.
However, I have also owned an 18” redtail that lived with a 12” arrowana from birth for over a year in a 6x 2 only to wake up one morning with the tail of the arro sticking out of his mouth.

im not naive, not stupid, nor irresponsible, BUT as I thought I was saying, it’s not as simple as saying No it will never work , or Yes it will always work.

Not sure who’s supposed to be clutching at straws as I certainly didn’t say that the combination should definitely be attempted.
Equally, nor did I say it definitely wouldn’t work.

Just out of curiosity, how do we decide what is a predator and what isn’t ?
An arrowana with a barb won’t work because the arrowana is a predator?! yet so many people keep neons with angelfish and this is ok?
Is an angelfish not a predator?
Will all angelfish eat the neons?
So how do we decide which fish will be ok with the angelfish if neons never will with any angelfish?
Maybe we ask the opinions of others and if all else fails, unfortunately we have to try them, and hopefully learn by our mistakes or our successes so we might pass this on to others.

Honestly almost any fish can momentarily become predatory if the right opportunity presents itself. I've seen it countless time where a guppy would just randomly eat another's fry if it swam right infront of its face. As far as I know guppies are naturally predatory but if the opportunity presents itself well it's anybody's guess on what will happen.

Personally I've tired neon with angel fish and just couldn't get it to work out. The angels would either just kill em if they were too big and if they were just small enough they'd become a snack. Lol lost about $40 worth of neons trying to get em to live with my angels.