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I’m really liking my Denison Barbs

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Magnum Man

Fish Herder
Jun 21, 2023
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Southern MN
I never had them before in my past aquarium life… I recently bought 3 ( they are about 4” ) to put in my Tim foil barb tank ( a 55 ) I have 2 flying foxes I bought local, and they have been moved around as I started up tanks… one a little bigger has been bossing around the smaller, and I hoped the Denison’s would help, since they are similar shape and size… it has helped a lot, right now, everyone is getting along… the Denison’s look nice, are peaceful, and torpedoes, that can get out of the way of the Tin foils at feeding time… I wish I could buy another 3, but afraid I’m at full bioload when everyone gets bigger

Any of you guys play with them???
Denision barbs, Rose line Sharks… I think there is 3 - 4 other names they go by as well
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Lovely fish, but you need a larger group, at least 8. They have some very specific requirements.

Compatibility/Temperament: Generally peaceful, but should not be kept with smaller fish that will likely be seen as food. It's water flow and cooler temperatures limit suitable tankmates to medium-sized barbs and danios, loaches, Garra and Devario species. Must be kept in a group, minimum 8 but preferably 10+; reports of aggressive behaviour are most probably due to the fish not being maintained in a sizeable group.

Origin and Habitat: Endemic to southwestern India. Inhabits fast-flowing hill streams and rivers, occurring in shoals in rocky pools with thick marginal vegetation. Water temperature averages 15-25C/59-77F; The species has a high oxygen requirement derived from fast-flowing water.

A larger tank is recommended as this fish will attain 6 inches, and a group of 8-10 needs space to be themselves.
Sorry to disappoint you but you need a larger group of dennisons for them to thrive, and certainly a larger tank, not only for the dennisons but your tinfoil barbs too!

A 55g is totally inadequate for both species.
Agree, you need more Denisons, a much bigger tank for tinfoils (they can grow to 18”+ and also need to be in a group, so shouldn’t really be sold for aquaria), and if the Flying Foxes are true Flying Foxes, they’re very much territorial loners so you need to remove one. If they’re ‘Siamese Flying Foxes’ they also need to be in a group.

‘A group’ usually means at least 8-10, preferably more. Siamese FFs space themselves out so a few less.
I'm trying to be nice, as I'm new here...

I would say putting a specific group size on any fish is pretty much hogwash... when I 1st put the Tin Foils ( at about 2"... they are maybe a little better than 4" right now ) in this tank ( yep they like to school ) I almost felt 5 was not enough... but school they did, funny seeing the biggest, & one of the only fish in the tank so timid... they almost dared each other to go across the tank... ( it's well planted with a big piece of drift wood in the middle ) 3 months later, & they have loosened up a lot, but still like to mostly hang together, but quite often they are spread out over the tank... the Dennisions from the start have been much more individual fish, right from the 1st day, they all swam around independently... not sure if they were more comfortable knowing the tin foils were the biggest fish in the tank??? nope nothing more dangerous around here than a Tin Foil barb or what??? I think these were not wild caught, so they may have lost some of their schooling instinct??? but my 3 are between 3-4" right now & totally at ease swimming alone in the tank... seen the schooling effects on Dwarf Corys, but I have several varieties, again, who are totally spread around their tanks, the ottos both school & go their own way at various times... betting 75% of the time with schooling and large groups, that is a trait of the wild caught fish, & may be not at all true anymore on farmed or aquarium bred fish??? I personally think it's also a ploy of the sellers to sell more fish... I bought 3 Dennisions, instead of the dealer recommended 6

on the tank size I know there will come a time that I need a bigger tank, or the fish get spread out more... had tanks as big as custom made 220 gallon before.... I'm just starting & filling some built in tanks that have sat dormant for 15 years... not opposed to getting some bigger tanks when needed... I really thought long & hard before buying the tin foils, before I made that commitment
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We can't learn and grow without allowing ourselves an open mind and humility.

You kept fish 20 years ago...while you were having a break, science and research carried on. Things that were common knowledge and practice back then have changed and so it's our responsibility as keepers of living things to do our best to learn how to help them have a happy and healthy existence in our care.

If you breed a wolf in captivity, does that change its natural instincts? Will its need to live in a pack with a hierarchy go away? Will its high prey drive go away? I think we can agree on a basic level that the answer is no.

A fish is not a wolf, but it is still a living creature with its own natural instincts. They are programmed to live a certain way and it's proven that they can live longer and thrive with less illness if we responsibly provide them with the right conditions they need for that to happen.

This forum is a brilliant platform with many very experienced and knowledgeable people who have been active in fishkeeping for years longer than I've been alive. I've been in this hobby 20 years and know peanuts compared to most here 😅 but thankfully they're eager to help and educate any who want to learn.


I'm sure 20 years from now we'll know even more and realise we've got it all wrong and be doing it completely different yet again .....
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I always give members the benefit of doubt when I have not previously interacted with them, and I therefore try to explain things as best as I can. With this in mind, I have some observations on post #5.

The number of fish in a species group is extremely important for the well-being of the fish. Scientific studies have proven this, no one can doubt it. One study examined groups of ten, five and three kept in separate tanks (obviously) of the species, and found that the fishin the groups of five and three showed marked increased aggression, and a latency to feed. Neither was the case with the group of ten. There have been other studies with similar results. The reason is that this need is part of the genetic makeup of a species. Itis an expectation the fish is born with, and when denied the fish has few ways to react to the danger as it perceives it. Shoaling is primarily a defense strategy, in the species DNA. The fish is more vulnerable without a decent-sized group. We cannot really put specific numbers on this, with a sharp clear dividing line between them, but it is blatantly clear that the fish is being impacted negatively. That means additional stress--and stress is the direct cause of over 90% of the diseases aquarium fish contract because it weakens their immune system (as it does in all of us).

Because this requirement and expectation is in the species' DNA it cannot be changed by tank rearing or any other thing. It is the way the species has evolved to function at its best, in its specific environment. Many would argue with justification that denying this is inhumane. I concur. The dealer who recommended six had more insight into fish biology and behaviour than is the case in many fish stores. It is always the poor fish that suffer, because they have no options when what they regard as basic is not provided for them. The citation in my signature block from a cichlid authority Paul Loiselle says it well.

Initial placement in a new environment usually has an impact on a fish's natural behaviours. This will likely change. There is considerable false hobby information on the internet and one has to sort out the reliable knowledge and follow it. It is not surprising that the biologists and authority aquarists in this hobby are almost always in agreement on matters of science. Ignore the rest.

Another maxim I learned some years ago and it has bnefited me considerably. I will never acquire any fish that I have not fully researched with respect to its environment (water parameters, aquascaping needs, numbers, temperament, and tank size at maturity, and for which I do not now at the time of acquisition have the appropriate aquarium that will provide the environment the fish requires to live well. Thrive and not just survive.
Denison barbs are certainly beautiful but their sudden popularity led to over harvesting and they are now on the endangered list.
So if anyone else is thinking of getting them, think hard if you can provide what they need - a very large tank for them to swim the long distances, a decent shoal and pristine water conditions. If not then they are unlikely to live a long life and this puts more pressure on the species.
Well... chastised again... go figure... you could have said... nice video, by the way, did you know...

but instead you are saying something more of opinion, than fact, & it's in fact, misleading 20 year old information

"the Denison Barb is somewhat unique in that exports of wild fish have ceased, but local commercial breeding of this species is thriving."

"In the mid-2000s the Denison barb was in danger of being wiped out from its native habitat by over-harvesting. Thanks to the efforts of knowledgeable amateur collectors and few universities, a path to successful captivity reproduction were developed."

"For more information on Denison barb breeding, you can contact the Indian state of Kerala University of Fisheries and Ocean Studies at http://kufos.ac.in/."

in this case their habitat is in danger, in combination with consumer pressure... as happens for many aquarium fish, but the hobby pressures breeders to breed these fish... if the locals helped build the habitat back, those could be reintroduced... hey, I bought mine from a fairly big seller, I'm 100% sure these were bred for the hobby I did not go out & live catch these fish, I did not post this video as a secret plan to make these fish extinct...

they actually look to be displaying a courting dance... just saying...
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@Magnum Man, I have stayed out of this discussion in older threads, but you keep repeating something that is just not true. The facts we are mentioning are scientifically proven and they are facts. Biologists have studied numbers for shoaling fish, and the results are what many have maintained for years.

Second, you cannot possibly know what a fish is thinking or how it feels. None of us can. All we can be reasonably certain of is that by providing what the fish expects and requires, we will more probably have success. And the fish will be healthier. And, "happy" if you want to throw that in.

Third, these requirements for numbers, or water flow, or temperature, are all part of the genetic make-up of each species. The fish "expect" these, and will be stressed without. It is as simple as that. The numbers studies for example found that in groups of three and five, the fish had increased aggression and even in time a latency to feed. Whereas the same species in groups of 10 had neither symptom. It is pretty clear that the fish consider all this essential. And so must we if we are to be responsible fishkeepers.

Fourth point, is what Ian Fuller said when a member of Corydoras World tried to argue that sand didn't matter, his fish were "happy." I fail to see how anyone can talk to their fish to know this. The fact that a fish swims, eats and spawns is not indicative of being well off, it is the fish's attempt to reproduce in spite of what we throw at it, because the need to reproduce is the strongest in most animals.
yep, I'm both a liar, & stupid, & too thick skinned to care... I'll continue to argue school / shoaling numbers... I'm positive those numbers change, as the fish ages ( in general ) when they are lunch to all their neighbors, the group is large, ( strength in numbers ) but as those fish grow up the group size typically gets smaller... if nothing else out of necessity, for food... often times several similar fish will shoal, if they feel the need, in an aquarium...

I'm going to use a non aquarium fish we have locally... black bull heads... in the spring, you can see clouds of them... groups of 100's or even 1000's, when they are less than 2"... somewhere between 2" & 6" these fish become solitary... there are some fish that mate in groups, but probably most pair up, & even if in a group, the group sizes decrease dramatically as they mature...

I've gotten a lot of good information from you, so maybe you should block me, if my opinions bother you...
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Sorry... I guess I'm not meant for social media... I'll go back to killing as many fish as I can, on my own...
Just out of interest do you have room for more denisons? I don't know enough about them to comment in too much detail but what's the worst that could happen if you did?

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