Pompom crab male/female?

[Moonfruit777]

Heyo,

I got these awesome pompom/boxer crab.
I wonder if it is a male or female crab - usually crabs have like a round or pointy shape on the belly but these seem kinda weird and I can't really tell.

the shell pattern also seems to be different on them - idk if that is related to sex or just size.

Also- does the sex even matter? Tank has 125G volume and I'll probably never see them again anyways (lol) but how big is their territory/ will they kill eachother?

Pics are following.

Thanks :)

 

[Moonfruit777]