Join Date: Oct 2010
Location: Victoria, Australia
In the past I was an advocate for betta sororities. I even wrote the thread about them on this forum. However, after witnessing the breakdown of my personal sorority, and reading about the failure of countless others, my opinion on the matter has changed. I don't believe a hobbyist can care about the welfare of their fish, and in the same breath, promote betta sororities. In my mind, the two are mutually exclusive.
I've found most sororities are not successful long-term, and a large aquarium is not enough to guarantee success. Even in 'successful' sororities, it seems like the lifespan of the females is adversely affected. It also seems like the risk of disease is much higher, compounded by the fact that many hobbyists don't practice proper quarantine procedures with their fish.
There's no getting around the fact that a sorority is a highly stressful environment, and all it takes is the wrong combination of females, and you can end up with a bloodbath.
What I usually see happen, is that a hobbyist will start off with a group of young females. As young females tend to be much less aggressive, the hobbyist is lulled into a false sense of security, believing that their sorority has been a success. Then the females start to hit maturity and the signs of aggression may be subtle at first, limited perhaps to posturing and some chasing. With some females, that is as much as they will ever do, but others will soon escalate to physical aggression. This is when you end up with injured or dead fish.
In my opinion, bettas are simply too unpredictable to live alongside conspecifics. I always say what they tolerate one day, they will try and kill the next. For example, I own a number of wild bettas. These are much more gregarious than their domesticated counterparts, so it's common to house them in pairs or mixed sex group. Even so, I've still had fish kill fish that they've lived alongside for several years without any issues.
I think a community tank featuring a single (suitable) betta of either sex, is a much safer option than a sorority. It's certainly kinder to the fish.