Originally Posted by teeneythebetta
The stripes your seeing that look like stress stripes just means she's developing her color. All young bettas have them at some point.
The girl with the vertical stripes- is she in the tank with a male or is her tank beside a male's tank? If she's in the tank, remove her immediately because males and females cannot coexist in one tank. If her tank is next to his, put a piece of cardboard or something between the tanks so they can't see each other.
AND.. For future reference.. Females MUST live in groups of 4 + in tanks 10 gallons of larger. So never put only two or three together. If not in a large enough group they will kill each other. Some females are individually too aggressive to live with others though.
The little girl is in a separate tank, thanks I'll put something between them. As for the group where I live female bettas are really difficult to find I was lucky to get those 2, can they live in separate 3g tanks?