The fish has a disease which may well be the disease known as 'dropsey'. The fish is in urgent need of medication/treatment which may or may not help it to survive.
a fat betta fish
i have heard that if you feed them a pea it helps.
well you first need at least a one gallon fish bowl and fish gravel and plants and stuff for them to hide in. fish food, and give them every once in a wile betta fish treats for fat.
It's hard to tell without a lot of details, but maybe you are feeding her too much... :( You are probably overfeeding her. Try not feeding her for a few days- but don't worry bettas can survive without food for a whole week.
Use parents of canary fat fish and silky fat fish.
a fat fish -hahazz-
If you overfeed a betta, they can become constipated which will often result in severe bloating and swim bladder issues. So they may "look" fat, but treating them for constipation helps. If you keep a betta in a small, cramped environment and feed him more than he needs, he can get fairly large all around. The problem is when his liver becomes fatty, which results in certain death. There is really no reason to over feed a fish.
A female Betta does not need a male for her to come into breeding condidion (develop ova). She does however need a male to assist her in order for her to lay (spawn) those eggs.
The ISBN of Too Fat to Fish is 9780385526562.
the fish get fat and possibly die. fat fish equal unhealthy fish
You should not keep female betta fish with males, unless you are breeding them and research about it first. The females are going to lay eggs. After they lay eggs, remove them from the tank, and leave the male in the tank.
Too Fat to Fish has 320 pages.