This is why you should never have more than one male betta in a tank. It's also recommended not to combine male and female bettas in an aquarium except for mating. Female bettas aren't nearly as ...

and they should never share their tank with another betta fish. The males of the species will fight one another, and not all female betta fish get along with other betta fish. "All betta fish ...

Betta fish—also known as Siamese fighting ... He then puts on a display to attract a female, becoming brighter and spreading out his fins. If a female approves of the nest, she turns darker ...