In article ,
says...
It is aggressive mating. The female can potentially die from exhaustion
trying to get away, one way to prevent harm to the female is to get more
females to divert the males aggressive mating intentions. Good luck and
later!

I'm reluctant to add any more fish to the tank, as it's already
stocked to capacity. But I do think you're right that there aren't
enough females for the males. And that leads to another question:

The two black mollies are definitely one male, one female, and the
silver molly is definitely female. The large sailfin molly is
definitely a male - but I'm not so sure about the other orange-
coloured molly. I *thought* it was a female sailfin, but now I'm
wondering if it's not a sailfin at all, but rather just an orange
molly - and a male one at that.

The anal fin has the pointed appearance of the male; I had thought it
was a female because it is smaller than the male sailfin and doesn't
display the impressive dorsal fin or tail. But I'm thinking I got
that wrong.

The only other distinguishing characteristic I see is their eyes -
the smaller orange-coloured molly has black eyes, like the rest of my
mollies, but the large sailfin has red eyes. I've no idea if this is
relevant at all.

Opinions?

--
FishNoob