That definitely is a female, but I have never seen female bettas build bubble nests . . . And I used to breed them all of the time. XP It does not look like a male (round tail betta, short tail betta, whatever you wanna call it) at all. The head is far too small. It's a female . . . and there is no way that it'll breed on its own, lol. Males tend to build bubble nests in hopes of a female coming along. But yeah, it's a female . . . a lesbian. XD Jk jk.