Help me sex my Betta!

[valeriajime]

I went to the pet store recently and purchased a “male” koi betta. It’s hard to tell because he has the general build of a female.

 

[valeriajime]

this is him/her flaring

 

[psk]

grab a mirror and see if it flares at its reflection? I don't think females flare all too often too.

 

[kj287]

Try googling “female betta egg spot”.
I could be wrong, but from everything I’ve looked up that seems to be the best way to tell them apart. We’ve got a young female betta and it’s pretty easy to see in the right position.
I don’t see an egg spot in the pics, so yours might really be a male, but you’ll be able to get a better look in person.
Hope that helps!

 

[SaraB]

Finding an egg spot would definitely tell you 100% if it's a female. Yours might be a male plakat koi, they have shorter fins.

 

[RisSkirata]

Judging by the flailing and lack of N egg spot, I would say it was all male. He’s a koi plako.

My little Black Beauty is a plako male. Plakos just don’t have the longer showy fins like the veil tails and crowntails.