identifying the sex of my kribensis

[rangerd]

I'm pretty sure both of those kribensis are females.

Thanks a lot, coltin.

[rangerd]

By the way, do females usually fight with each other? The smaller one seems really aggressive towards the other female.

It's also doing this weird thing where it curls its side and shakes - is that aggression or is it trying to impress somehow? It's kinda like what my rainbows do when they're spawning, so I'm not sure what's going on here. Maybe it's some kind of defence move or something?