Aggressive Female Mollies?

[DaveyG]

Hi all

I am having a bit of trouble with some female mollies chasing others.

I have 2 marble mollies and 2 black mollies and 1 white molly (all female, no males) all of which have been in the tank for about 6 months (all joined at the same time).

The 2 black mollies have started really going for the marbles, they are ganging up on them and chasing them around and I know its only a matter of time before the marbles get too stressed.

I am worried that my tank is overstocked because I have quite a few guppies and platies and have left them to breed and so the population has grown.

My tank is 40 gallons and has:

2 male guppies
5 female guppies
5 female mollies
5 male platies
5 female platies
and a few blue tetras.

I didn't think it was overstocked but I could be wrong? There's plenty of live plants in there and caves etc.

Is that the problem or is there another reason these 2 mollies have decided to start being aggressive towards the others? They have been separated for now.

Thanks!

 

[hughessomefish]

you should put atleast one male in the tank because,one or two of the females is starting to take the alpha spot in the school,but idk if you should get a nother male well,humm

 

[OldMan47]

My first guess is the same as yours DaveyG. The overstocking, the crowding, brings out the aggressiveness of some fish and mollies are among the ones that I have seen it happen with.

 

[Fishaholic7]

I'd have to agree with OldMan47 and DaveyG...overstocking can certainly lead to aggression. Do you have a smaller, say 10 gallon, tank that you can use for fry? The crowding is going to get worse with each batch of fry.