Schools

[~~~]

Might just be this forum or something, but I have noticed a LOT of people in this forum keeping cories, danios, tetras, barbs, loaches, otos, characins, and the like in schools below 8 or so.
I mean, all these fish should be kept in schools... but why don't you? I mean, I know you guys are more about the plants rather than fish...

I know I'm making a generalisation, but why do you keep them in groups of 5 or 6?

[AzFishKid]

What makes you think that a school of fish has to be no less than 8? It's all subjective, really.

I think that most people will agree that the more you have the better, but does keeping them in a smaller group harm them? Probably not.

[Schwartzy61]

We do?

[livingword26]

Who says 5 isn't enough?

[~~~]

Because in the wild, they school in the hundreds perhaps thousands, and then we cram them in a tank with 5 and expect them to be happy.....?
The difference in their behavior is phenomenal. Take 3 fish, put em in. They hide, stressed- which means they are prone to disease(s). They also nip. A lot. Up it to six. Less hiding. Less stressed. Up it to 10. and so on. The difference in behavior, according to many, is amazing.
I think that if I crammed you (guys) in some big place, and then put 4 other humans in there, where there could be thousands of random apes and such, how would you be? And then say, I add 7 more. And another 10. I doubt you would act quite the same...?
Does it harm them? We may never know, but it certainly influences stress. And stress, as you all quite know very well, is a very bad thing....

Thats my opinion. At least you guys don't keep goldfish and bala sharks, LOL

[CatB]

i think it really depends on the species.
like otos or cories seem to do fine with two or three, sometimes even one.
but take like...CPD's and have only three, they're gonna be shy as heck.
or take tiger barbs and have three, they're going to terrorize your tank.
some schooling/shoaling species require as many individuals as you can get, others don't.

mostly, people do it because they don't have room in their tanks for more.
yeah, if i could have a 120 gallon tank i WOULD get 20 of each schooling species i want. but i can't, i can only afford a ten gallon, so i'm going to get eight of one and five of another. non-schooling species usually don't work so well together, or they get too big to have a bunch of different ones.

[~~~]

On the ottos you are right, I would rather not starve 10 of them. They seem fine. Cories, meh. I would keep them in schools.
About the 10g, why don't you keep an adequate school of only one species? You could have 10-20 in there comfortably, instead you are putting 2 species in...

[CatB]

Originally Posted by ~~~

On the ottos you are right, I would rather not starve 10 of them. They seem fine. Cories, meh. I would keep them in schools.
About the 10g, why don't you keep an adequate school of only one species? You could have 10-20 in there comfortably, instead you are putting 2 species in...

well, that was a hypothetical situation.
but i am going to have a ten gallon soon, i'm planning on eight serpae tetras and five panda cories. i've seen similar tanks where both species are happily schooling and not hiding in groups of that size.
while i appreciate the beauty of a large school of one species, most people- myself included- want some variation in their tanks. now, if i only had room for eight of any fish, i'd get one species rather than having hardly-even-schools of four or something. but i've seen these species not suffering in smaller groups of 5+, so it doesn't seem a terribly bad thing to do. i think what makes an "adequate" school varies a lot between species, the shyer/smaller ones do worse in smaller schools, but most seem fine.

[~~~]

15 neons would be much happier than the 8 serpaes/5 cories....
Variation? I would put in some shrimp and snails....

[CatB]

Originally Posted by ~~~

15 neons would be much happier than the 8 serpaes/5 cories....
Variation? I would put in some shrimp and snails....

i mean. they're fish. they're not exactly geniuses? you can't really compare it to isolating social mammals, like humans or monkeys or dolphins.
if you're going to argue that it's nothing like the wild, then you can't really argue that we should be keeping fish captive at all. 10 gallon tank =/= miles upon miles of open lake/river/ocean/etc.
yeah, if i had like...two serpaes and one cory, they'd be MISERABLE. but like i said, i've SEEN groups this size and they school just fine, don't nip anybody, and don't suffer.

[reignOfFred]

I think variables need to be looked at seperately and CatB makes a point.

First, it depends on the fish - Some are shyer and more timid and more reliant on higher numbers than others, and some types can get aggressive in low numbers while others stay peaceful. Some are very tight schoolers, while others are loose groupers. Some will continue to be active and peaceful in low numbers, others get shy and stressed.

Second, we can look at the tank size. 6 neons in a 15 gallon tank is much different than 6 neons in a 150 gallon tank.

Third, we can in some cases look at tankmates - maybe 6 serpaes will work fine as the main population of the tank, but when I kept them with a 9" nicaraguensis cichlid I ensured a nice group of 20 to instill confidence with such a big, albeit harmless, fish in their midst.


I had a group of white clouds for about a year but wasn't really into them, so I gave them away. After the taker left it turned out I missed one. He lived in that tank for 3 more years, the only of his kind, in a tropical tank, and he grew big and was always out and about. Would I purposely buy just one - not at all, but it is just case and point that not all schoolers/groupers suffer in small numbers, or even singly.

I also had a single Pygmy corydora for a few months, and he was active and constantly swimming and foraging and never once showed signs of stress. now, of course, he has a group because despite my playing the devils advocate I only keep grouping fish in groups, but just another example that while the fish may not be able to display their full grouping behaviour, saying the fish will automatically suffer alone or in tiny groups is short sighted.

[CatB]

Originally Posted by reignOfFred

I think variables need to be looked at seperately and CatB makes a point.

First, it depends on the fish - Some are shyer and more timid and more reliant on higher numbers than others, and some types can get aggressive in low numbers while others stay peaceful. Some are very tight schoolers, while others are loose groupers. Some will continue to be active and peaceful in low numbers, others get shy and stressed.

Second, we can look at the tank size. 6 neons in a 15 gallon tank is much different than 6 neons in a 150 gallon tank.

Third, we can in some cases look at tankmates - maybe 6 serpaes will work fine as the main population of the tank, but when I kept them with a 9" nicaraguensis cichlid I ensured a nice group of 20 to instill confidence with such a big, albeit harmless, fish in their midst.


I had a group of white clouds for about a year but wasn't really into them, so I gave them away. After the taker left it turned out I missed one. He lived in that tank for 3 more years, the only of his kind, in a tropical tank, and he grew big and was always out and about. Would I purposely buy just one - not at all, but it is just case and point that not all schoolers/groupers suffer in small numbers, or even singly.

I also had a single Pygmy corydora for a few months, and he was active and constantly swimming and foraging and never once showed signs of stress. now, of course, he has a group because despite my playing the devils advocate I only keep grouping fish in groups, but just another example that while the fish may not be able to display their full grouping behaviour, saying the fish will automatically suffer alone or in tiny groups is short sighted.

i feel like this basically says it all.
you make a good point about the tank size and tankmates; a smaller group in a smaller tank is a lot different than a smaller group in a bigger tank, where they would basically get lost in their surroundings, and ten tetras in a tank with a mating pair of apistos would be a lot more shy than they would if they were by themselves.
good topic analysis right here.

[~~~]

Wow, fred.
Yes, they don't all suffer, but purposely keeping them in small groups in a large enough tank because you want more variety...?

[reignOfFred]

but purposely keeping them in small groups in a large enough tank because you want more variety...?

If such a thing is a sin, I am guilty. My 29 has 5 kuhlis and 5 Pygmy Cory's - Am I really so evil for not going with 10 of one or the other? The kuhlis are 3 years old and active and healthy. The Cory's I've only had half a year but are very active and healthy (and the original one never seems to hang out with the others). I like the tank this way, and judging by the fish themselves, I fail to see a problem. Again, I look at the variables - these fish are free of aggression, in this tank the kuhli's are by far the biggest fish - no threats at all. The tank is well planted throughout, adding lots of comfort and security. Any situation should be looked at as it's own.

[~~~]

Not quite so evil b/c both fish are ok with <8 of specimens. Especially Khulis. I don't know much bout loaches, but they aren't the school-needers that danios/tetras/barbs are.