Schooling Fish: Six The Magic Number

[Kittiee Katt]

Hi all, I've noticed that when reading information on schooling fish, that everything says "groups of six or more"... Why six? Why not seven or five?

I understand the reasons for keeping certain fish in groups, but I can't understand why a minimum of six. Have any studies been done on such things? How do we know that a group of six corydoras isn't just as anxious or uncomfortable as a group of four in the same situation? Who's to say that groups of 15 shouldn't be the minimum? Maybe 'six' is a number that someone has pulled off the top of their head that just caught on? I want to know, why six?

I would love to read any studies that have been done in the area, if anyone knows of any can they please link me?

Thanks in advance. Also, please, no arguing, if your opinion differs from someone else's, just agree to disagree or politely post facts to support your opinions - after all, facts are what I'm after.

 

[Drstrangelove]

It's a general rule of thumb like "eat an apple a day" or "drink 8 glasses of water a day."

There are hundreds of species of fish (if not thousands) that school or shoal. And I doubt that there has been a study for each or perhaps any of those species to see if 6 is the right minimum number.

People can and do acquire species and find that 2 or 3 is a disaster while 6 or 7 works great, while other people find that 2 or 3 worked out fine. There are many factors that could influence that such as the size of the tank, the particular species, the prior experience of the individual fish, the temperature and feeding arrangements, plant decor, etc.

In many cases, there is no need to worry as the fish are so small that an extra few is hardly a concern. As for truly huge fish, very few people can house a school of them, so the "scientist" has no interest to conduct a large expensive study to find the "proper" number of monsters in a tank.

 

[dan518]

i have found in some species, rainbow/silver dollers/red eye tetra, you need 6 to disperse the aggression from the dominate fish any less and it starts to kill the others off . so 6 a minimum number.

 

[Bottomfeeder]

I usually go at least six for aggressive species, but at least three for less aggressive species. Some schooling fish will beat argue amongst the school, and in smaller numbers, the aggression is not distributed enough and the fish tend to get tattered and stressed. Some fish seem to just enjoy each other's company, and they probably don't need such a large school... although they would probably appreciate it.

When I kept loaches, I kept them in groups of three. It seems to disperse the aggression enough for them. But then again, they were in a big heavily decorated tank, and they were able to avoid each other as needed.

 

[koltsixx]

Hi all, I've noticed that when reading information on schooling fish, that everything says "groups of six or more"... Why six? Why not seven or five?

I understand the reasons for keeping certain fish in groups, but I can't understand why a minimum of six. Have any studies been done on such things? How do we know that a group of six corydoras isn't just as anxious or uncomfortable as a group of four in the same situation? Who's to say that groups of 15 shouldn't be the minimum? Maybe 'six' is a number that someone has pulled off the top of their head that just caught on? I want to know, why six?

I would love to read any studies that have been done in the area, if anyone knows of any can they please link me?

Thanks in advance. Also, please, no arguing, if your opinion differs from someone else's, just agree to disagree or politely post facts to support your opinions - after all, facts are what I'm after.

I don't know of any studies or if there are any out there but I imagine the "six or more" came from a majority of peoples personal experiences passed on from one to the next. This probably continued until the majority of the community either found out it was valid suggestion or just accepted it as one due to how many times they heard it repeated.

For myself I know I've tried different variations in the number of a group and the minimum and I had the most success with groups of 6 or more. I imagine many who passed the same info based it on their own experiences and came to the same conclusion along the same lines that I had. For instance for me there have been times I longed after a fish best kept in groups but due to money or tank limitations or availability or practical experience, bought the fish and tried working with less fish then the recommended 6 and had issues.

My most recent attempt was Afican Scats. They're pretty pricey so I tried 3 at first, it was a no go. Then tried 5, still they where singling out one and preventing one Scat from eating enough. So I eventually ponied up and bought a sixth and Wha-La harmony. I how ever liked them so much I continued buying and now have 8. While I can't account for others, again IME when I went over 6 I didn't notice any particular difference. That wasn't always the case of course but it worked for me more often then not.

All in all it's a decent guideline IMO. It's not to be taken as word but taken with a grain of salt and combined with the appropriate research.

 

[ehh]

I don't know of any studies or if there are any out there but I imagine the "six or more" came from a majority of peoples personal experiences passed on from one to the next. This probably continued until the majority of the community either found out it was valid suggestion or just accepted it as one due to how many times they heard it repeated.

this is what i was thinking. I'm sure its based on collective experiences.
after keeping a few species of schooling fish myself, i think 6 is pretty conservative regardless of species. i think 10 is a good number lol

 

[koltsixx]

this is what i was thinking. I'm sure its based on collective experiences.
after keeping a few species of schooling fish myself, i think 6 is pretty conservative regardless of species. i think 10 is a good number lol

Then for the sake of my poor Scats buy me two more little buddies for them.

Seriously though you're totally right more is almost always better when it comes to schooling, shoaling. Fish that shoal or school do so because for them it increases their chance at survival. So if a fish naturally shoals/ schools logically one might assume they're likely to feel more secure(=happy?) the larger group they're kept in.

 

[Allan01230]

I have 3 redhook silver dollars in an 85 along with 5 giant danios and the dollars and danios all school together I keep it well planted with fake plants. (real once all got eaten) All the fish stay out in the open and never hide.

 

[Kittiee Katt]

Thanks all for the replies. I pretty much agree with everything said, but would still be very interested to read any studies along the line of.

If anyone finds any studies in the future on this, please remember me!

 

[Spiritofthesoul]

I usually go for as many as my tank can handle (without compromising on the no. of other species I can keep of course). To me, 6 just is a benchmark, a bare minimum. So yeah, always aim for more.