Description of a Male Vs. Female Beta

The Siamese fighting fish or betta is a popular freshwater aquarium species. Primarily a carnivorous surface feeder, the betta's wild relatives are found in the rice paddies of Thailand and Cambodia. There are significant differences between male and female betta fish.

  1. Fin and Tail

    • One of the most obvious ways to sex a mature betta is by observing the fins and tail. Male bettas are bred to grow long and flowing fins and tails that are two to four times as long as those of females. Males also typically have a larger beard, or the membrane underneath the gill covers. Due to the male betta's beautiful fins and tail, pet stores tend to stock more males than females. Note that immature male bettas may also have short fins and that some female bettas with longer fins are now being bred.

    Body

    • Male bettas tend to have bodies that are bigger, longer and thinner than females. This characteristic is not always immediately obvious. The average size for any betta is approximately 2.4 inches long.

    Egg Spot or Ovipositor Tube

    • Female bettas have an egg spot or ovipositor tube located on her belly between her anal fin and ventrals. The egg spot looks like a small white speck or large grain of salt. The female will drop her eggs from this tube. Egg spots have been reported on some immature male bettas.

    Reproductive Behaviors

    • Male bettas will blow bubble nests on the water's surface and are responsible for caring for the eggs. Once the female releases her eggs during spawning, the male will chase her away, collect the sinking eggs in his mouth and deposit them in the bubble nest. He will repair the bubble nest as needed and make sure that none of the eggs sink to the bottom.

    Male Agression

    • Male bettas are generally more aggressive than females. Males will flare or display their beard, fins and tail upon encountering another male. Male bettas may also respond aggressively to their own reflection in a mirror. It is rare for a female betta to engage in this kind of aggressive display. Male bettas are normally kept secluded from each other and from other fish. Female bettas can be kept together in groups of three or more with careful monitoring.

    Color

    • Male bettas are generally more brightly colored than females. A male's body may be one color while the fins and tail display a complementary shade. Certain shades, including blue and turquoise, appear to be iridescent. Breeders are beginning to breed females in a wider variety of colors, but the female coloration still tends to be more subdued than that of males.