I have a grey guppy. She is pregnant for a few weeks. Her belly doesn't seem to grow much much her gravid spot is very dark and big. The gravid spot seems to grow more then her belly. Do all guppys need to get super fat before birth?
Not all pregnant females get big. In general it means the fry will be small in size or just a low number. Happens as well... Nothing to worry about. And each pregnancy of the same female can be different.