Sexing

Male Bettas are generally more colourful and have much larger fins than females. Females have short fins, and when viewed in aquarium shops or in a stressed condition they appear to lack colour. But once in a suitable tank and have settled in their colours will come through also.

Females also have an ovipositor visible, a small white dot just behind their ventral fins. A female's ventral fins will also be shorter than a male's, and her anal fin will be rounded and more rectangular rather than finishing to a point, as a male's does. Both male and female fish will flare their gills and extend their fins, however the gills on a female will be smaller, whereas a male's gills when flared will go right around the head like a ruff.