Can I keep a group of all male mollies? No females?

Actually, in the few years I've been breeding mollies...Bachelor groups actually do pretty well without females to fight over.

It depends on space and hiding. Those are the two biggest things. Say you want five boys...you will want at least a 25+ gallon tank, bigger is better, with a lot of plants and caves. If you can get a 30 gallon that'd be about perfect for five boys and some cories, kuhli loaches or other small, peaceful bottom-dwellers. You want at least 5-8 gallons per fish as a bare minimum, if they don't have the space, they may fight for it. Same if you had girls too, but it'll be worse with boys if you don't have the space. With proper space they wont fight so hard, many think with less space they wont fight as hard because they don't have room to do so, but this is false with mollies. The only time I ever had so much trouble with sparring males was when I QT'd three in a ten gallon for two weeks, right away fight, fight, fight, plus their bioload is very high and they don't go well in small spaces. I used my twenty gallon as my QT after and had no issues with that! lol I've rarely had issues with males anyways, it's females I tend to get aggression issues with...

There may be sparring, it happens. Boys will be boys, but without females to chase, their spars will likely be...half-er...yeah, they wont go full force. lol Why risk injury without any benefits? Fish aren't as dumb as people think...though there are that special...many. LOL

Anyways, yeah, a bachelor group should do just fine. You may have a problem male or two, and you'll want to remove those. Any who rip fins, you want them out or it actually could start a mess. But in all likelihood, they will just do mini-spars and get along alright, may even try to mate with each other(if that happens don't be fooled unless you're unsure if you really do have all males), since livebearers are always trying to mate, even out of species or with other males.

Ahh, I missed that part....wait there isn't any mention of that here. If it's a ten gallon, zero mollies. They get too big, have too high of a bioload, it's more trouble than it's worth trying to keep it clean, let alone to keep aggression down, hard enough in a twenty with just four or five of them at that.
Mollies like to breed, but as far as aggression goes: They usually only show aggression when multiple males are chasing females, when pregnant, or when there isn't enough space...spikes in water parameters can also cause that. If you keep them in a proper tank for their group and bioload, chances are you wont have any aggression. At least not often. There shouldn't be any "Dominance" with them even with females, no pack-leaders with mollies, just fights over girls when one is in heat...Otherwise they shouldn't "fight" at all.

dancelady said:

When are they NOT in heat??? Maybe when delivering the babies? Males after them ALL the time!!!

I know my 20G is too small for much, but I do have 6 Mollies, 3" and 1.5", 4 females, 2 males. (was 6 females, but took 2 out). Two had babies, so were put into another tank. I can see that the Alpha male, Sailfin GoldDust/orange with green sparkly fins, who is extremely aggressive, is the head fish. He is the dominant one, keeps the other one hiding. So I probably will get many orange fish from him, as the other one tries to go to a female, and is chased away by the orange male. He is a handsome one, so no problems there. But having bred birds once upon a time, I can tell a dominant one for sure.

I think if I had a larger tank, there wouldn't be any sparring, but for a small tank, you have to live with the extra cleaning and heavy bioload to keep the water sparkling. It is clear now, and all the 10G tanks, too. Never had a problem with the 10G tanks, once I learned what cycling is, and how to do it. Thank you for all the tips, and I am getting better at it now.
:lol:

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Your "Dominant female" is telling the other that there is not enough space there, she'll die if you don't do something.

lol the heat thing made me laugh, this is true...however, there is a difference. Mollies are always trying to mate, but when a female is receptive it's another matter: She puts out hormones and scents like any other female in heat, and the males go even more nuts. Especially around birthing time, honestly...they smell that, they want...to breed. Almost got bad there.

The problem with having them in a ten gallon tank is just about everything from space, to bioload. Just not good for them, and it's a bigger problem if you think it's ok to keep them in there and say there's been no issues. .-.


I feel like I'm getting off topic here...but yeah. If you have a ten gal, Grace, don't go for mollies. You're better off with endlers livebearers or guppies. Male endlers are the best, they do wonderful in bachelor groups, they're small, they're beautiful, and rarely nip each other. Guppies will also do ok, but with boys...well, guppies often chew at each others tails. Real pain in the butt, they are. Literally. LOL Hybrid endler/guppy crosses are about as bad as guppies.