I think he's a she, but it's a little... complicated.

[Sena Hansler]

Lol that would be cool :p

[trilobite]

If you can see a yellowy mass behind the stomach then its a girl.
The yellow mass are the ovaries.
They look like this

[finney]

I'll look for that, thanks. On this fish it should be pretty easy to see if it's there or not. How old does a fish need to be in order to see it?

[Sena Hansler]

From what I learned, bettas mature around 3-5 months? And yours is definitely about that age as they are sold 3-4 months old, or older. All of mine for instance have been between 6-9 months.

[finney]

Well, we have a verdict!

Kaspar is:

1. Male and
2. "Only" an occular albino

His dorsal and caudal fins are developing more, identifying him as clearly male, and he's also developing a swatch of VERY bright royal blue right in the middle of his caudal fin, like his brother that I saw in the store. He may not be my OMG ALBINO, but I think he's even more beautiful with the bright blue.