Agreed entirelyHealth, size, colour, fin type, heritage . . .
You wouldn't just pick a female based on how they looked - you have to understand enough about genetics to be sure you'll start getting fry that you want and you need to be aware of their parents/grand parents so that you know what other traits might come out in the fry.

Hi, to me it looks like a chewed up VT? So, it wouldn't really matter what the female would be, VTS are most dominent so most of your fry will be VT.Right, Look here, its the multi coloured one,
http/img684.imageshack.us/slideshow/webplayer.php?id=dscf0518.jpg
No idea of parents.
Tortea