how can you tell if a betta is a male or a female.. my sister had two (in seperate tanks of course) and she was curious. thanks

The most common way that I know of is the length of their fins.. The males at our pet store have the long flowing tail and fins while the females have real short finnage.

Sapphyra is right... Also, the females tend to be slightly duller in color.
Plus the males will build bubble nests.

Cheers!

Why and does it help or hurt anything? My beta does this all the time!

When bettas breed, the father is the one who takes care of the eggs. He keeps them in a bubble nest, so they float in one spot that he can guard. Therefore, bubble nests can be a sign that he's happy and healthy overall, because he thinks he's ready to breed. It doesn't make any difference if he builds them or not if he isn't going to be breeding. And don't feel bad about disturbing it when you do water changes, I really don't think it bothers them. Repairing it gives them something to do, lol.

Okay you cant go by finnage or bubble nests. Both sexes build nests and there are such things as short finned males, longer finned females and brightly colored females. THe only way to tell for sure is by a white bump found on the females belly between her ventral fins. Its very obvious if its there. Also the females are aggressive like the males but not usually as much. You should not keep males and females together, and should only have females in a large tank, at least 10 gallons or more. Even then its not a guarantee that they will go together.

http://www.aquariumfish.net/catalog_pages/...tta_females.htm

thoughs r females


http://www.aquariumfish.net/catalog_pages/..._males.htm#top2


thees r males

You can find out from the fins and
if theres a white spot were there bottoms are
i think it means it's a female