I have some platies and can never tell at the pet store which are male and which are female, so its allways a bit if a gamble when i get them. My understanding is that the males tend to harass the females so in order to get the right balance in the tank a ratio between 2:1 and 3:1 females to males is required. Can anyone tell me how you can identify the sex?

One has a cock one has a *****