White cloud mountain minnow gender?

[eli5]

Hello everyone

This is my very first post here – I'd like to gender my White Cloud Mounain Minnows (gold type).

There's one bigger than the other three who's also flaring, chasing and overall more colorful, so I'm guessing that's a male.

I'm asking bc I got these two days ago (they were the last ones in the store) and can go and pick up some more tomorrow. So I want to make sure the gender ratio is ok

Could somebody help me out?

 

[GaryE]

Fresh out of the store, you can make mistakes from photos, as they need some recovery time. I find them easy to sex 'live'. It's the belly shape I go by - slender males, heavier bellied females.