Bettas, also known as Siamese fighting fish, reproduce via external fertilization, which means that the female releases eggs and the male releases milt. The male is responsible for creating a "bubble nest," which is where the eggs are kept until they hatch.
As with many aquarium fish, male bettas are responsible for rearing the young. The male chases the female away from the bubble nest, to prevent her from eating the eggs.
Bettas perform a "nuptial embrace" during the mating process. The male bends over the female's back as she releases her eggs into the water. In captivity, the female is usually removed from the tank, after spawning occurs.