Male vs Female Betta – Differences and Determining Gender

Are you thinking of buying a betta fish? Are you already an owner who wants to breed from your beloved betta? If that’s you, you’ll need to know how to tell the difference between a male and female betta fish.

In this article, I tell you everything you need to know about determining betta fish gender.

Wild vs Domesticated Betta Splendens

Wild betta fish look completely different from those that you see in pet stores.

Male wild bettas lack the flowing fins and brilliant array of colors that are boasted by their captive-bred relatives, being a somewhat dull, gray-green color with short, stubby fins. In wild betta fish, females look very similar to males, although they are slightly smaller.

Sexual Dimorphism

“Sexual dimorphism” is a term that’s used frequently in articles about tropical fish, including bettas.

Basically, sexual dimorphism refers to the degree of difference between males and females of the same species. The terms “weak” and “strong” are also applied to a creature’s sexual dimorphism.

In the case of betta fish, it’s true to say that wild bettas have a weak sexual dimorphism. In other words, it’s very difficult to tell the sexes apart. However, captive-bred betta fish have strong sexual dimorphism because the male of the species is very different in looks and behavior to the female.

That’s because captive bettas are bred for their spectacular finnage and rainbow array of colors, including metallics. Wild betta fish are naturally muted in color and have short fins and tails.

Over the years, the basic betta genes of wild fish have been toyed with by enthusiasts to create the beautiful anomalies that result in the strong sexual dimorphism of today’s captive-bred bettas.

Pet Store Stocking

How you purchase your betta fish can be an indicator of the fish’s gender.

In my experience, it’s generally male betta fish that you find for sale in small pet and fish stores. That’s because the males of the species are more eye-catching with gorgeous bright colors and flowing fins. Consequently, most hobbyists want a male betta, rather than females, which are drab in comparison.

You can buy female bettas too, but I’ve found that it’s usually more specialist aquarist stores that sell them.

So, if you buy a betta from a small, regular pet store, ask the assistant if the fish is male or female. If they’re experienced, the assistant should know how to tell the gender of a betta fish.

However, if in doubt, assume that the betta is male.

Physical Differences in Appearance

Female and male bettas are very different in appearance:

Color

Male	Female
Male bettas are brightly colored Male bettas do not display stripes	Female bettas are more subdued in color Female bettas develop vertical stripes when in mating condition

Fins and Tail

Male	Female
Some varieties of male bettas have long, flowing finnage The male’s ventral fins are longer and thicker than those of the female	Female bettas have short fins In short-finned Placat bettas, the female’s caudal fin is shorter than that of the male

Body Shape

Male	Female
Male bettas are slim and narrow	Female bettas are shorter and wider-bodied

Size

Juvenile male and female bettas are the same sizes.

Male	Female
Adult male bettas measure 2.5 to 3 inches in length	Adult female betta size is 2 to 2.25 inches in length

Egg Spot

If the fish is female, you will see a tiny white dot between the ventral and anal fins.

The white dot is the fish’s “egg spot” or ovipositor. The ovipositor is part of the female fish’s sexual anatomy and is used to deposit her eggs during spawning.

The betta’s egg spot is so tiny that it can be difficult to see. Try taking a photo of your betta from the side and then magnify the photo to see the spot.

Male	Female
Male bettas do not have an “egg spot”	Mature female bettas have an “egg spot”

Betta Beard

Betta fish have an opercular membrane situated underneath the gill plate cover. The membrane is visible when the fish flares its gill plates, resembling a “beard.”

Male	Female
Male bettas have a large beard that can be seen even when the fish is not flaring	Females have a much smaller beard that is not as visible even when flaring

Behavioral Differences

There are some notable differences in the behavior of male and female bettas:

Flaring

Male	Female
Male bettas flare their gills as a display of aggression Males do not adopt a head-down position when flaring	Females flare at other females in a sorority to indicate dominance Female bettas adopt a head-down posture when flaring

Aggression

Male	Female
Male bettas are highly aggressive toward other males and will fight Male bettas can be aggressive toward other species that have trailing fins	Female bettas can be aggressive toward each other if kept in pairs Female bettas are generally peaceful in a community tank

Bubble Nest Building

Male	Female
Male bettas blow bubble nests, even if there is no female in the tank	Female bettas very rarely create bubble nests

In Conclusion

Now you know how to tell the difference between female and male bettas!

In general, males have extravagant finnage and bright colors, whereas females have short fins and are less gaudy in appearance. Consequently, it’s usually male fish that you’ll find for sale in regular pet stores.