Big .....small.....huh?

I think there is something weird.
It has happened 3 times.
My two old guppies(Dead) and my molly had big tummies then they became small.
Huh???

 

More info please.

Were they female?
How old were the guppies?
What was in the tank with them?

Was the molly a male or female?
Is the molly still alive, you do not list (dead) beside of it?

(Mollies and guppies can crossbreed to create a sterile and in my opinion, ugly fish called a muppy.)

Will check back later for the added info.

 

HI Kelacon. Here's more questions for ya

How long did the swelling last?
Did you see raised scales on their bellies at all
Could it quite simply be caused by pregnancy/overfeeding?

 

did you make any changes to the tank before this started happening? food, maintenance, etc?

 

Molly is not dead and all are female. Wow... a muppy cool.