How do you tell the sex of guppies?

hi dreama

Male guppies are smaller and are more brightly coloured, they also have an adapted anal fin to mate with the females.
Females are usually bigger and a dull colour with a coloured shorter tail. Females have a rounded anal fin and a gravid spot which is the area behind their bellies to show how advanced the babies are.
The heavier in pregnancy she is the darker this spot will become.

Male guppys have big, long, showy, fancy tails femals have short ones

some examples c/o go0gle images

females....

that will teach me for taking so long to do my reply! sandy beat me! ah well here are the male picts too

na na na na na

male's anal fin is not round. it is rather sharp-looking. has a lot of coloration.

female's stomach are much more rounder, and anal fin is rounded. has little to no color. very bland.