Platy - male or female ?

[CyprusSteve]

Could someone kindly advise me , in as simple terms as possible, how I differentiate between male and female platy - I am vey new to this, so, please keep your advice as non technical as possible
Iy helps me if you talk in terns of colouration - I have looked this up on the internet, and I THINK that the male is the more colourful of the two , with a more red head and fins, but, I really am not sure.
I want to add about 6 platy to my tank, but, all same sex - I do not want to breed -will this be ok ?
Thanks
Steve

 

[Squishiebabe]

Yes it will be okay, as long as they are positively all the same sex...You Dont want fry, same as me.
Find that out, how to tell the sex or ask the lfs, yesterday i met an actual very informed employee, who knew loads.
There is actually a fin that you can tell if they are male/female...


<normally the males are more colorful and have larger more attractive fins. the females are more drab in their coloration
and have short fins. IanB> thanks <<Mmm, and as livebearing toothed carps with internal fertilization, the males have modified anal fins (the one underneath their bodies, behind the "belly"). On males these are tube-shaped and on females they're fan-shaped in profile.>>
From..Platys

gonopodium
EDIT:Top is female, bottom is male..

 

[dwarfgourami]

Don't trust to colouration; there are so many different colour variants out there and a female of a brightly coloured variant will be brighter than a male of some duller variant. Go by the gonopodium as shown in squishiebabe's post; it is the only reliable guide. Females are often fatter than males, but again not totally reliable. Platies can be black, blue, yellow or pink as well as red, regardless of sex, so redness won't help you either. My females are black and yellow, and red and black respectively, and my male is a totally goofy pink.

If you buy females, keeping them apart from males in your tank may not help, as they may already be pregnant from the shop, or from the breeder, and livebearers can store sperm for quite a long time. Then again, the parents may sort your problem out by eating your fry, but this is not foolproof (though I am gambling on it, myself).