Can you tell by the size of the bubbles if it's a male or female betta?

[MSG]

Bueroza the one I originally posted a "HELP ME ID" thread about, is blowing bubbles 3x the size of the other girls. Even the largest females who are over 2" long willl blow bubbles, but they're tiny compared to Bueroza's bubbles.

Bueroza is still 1.5", but the ovipositor is still clearly visible & still resembles an angelfish to me.

Let me know what you think. I'm pretty sure Bueroza is a male based on the bubbles on his side. I included some photos to give you a size comparison.

Another thing, doesn't the yellow girl look like she has fin rot?

[vilmarisv]

Bubble nests are not an indicaton of gender.
Females can make big bubble nests too.
I recently had a female release eggs in her tank, she placed them in a nest and was tending them just like males do. Of course, she ate them the next day because they weren't fertilized but it's very interesting to see.

[MSG]

Hm.... The size of the bubble is still obviously 3x larger than the others. I'm going to keep him separated. Hopefully that's been the cause of all the fighting.

I'll try the flare test later. But it doesn't seem too bothered by mirrors.