When keeping bettas, it’s important to know the gender of your fish so you can meet their needs accordingly. Male bettas are more prone to aggression and fin-nipping, making them a threat to other male bettas. On the other hand, female bettas are more prone to being shy and timid around new objects, so keeping them away from male bettas is essential for their safety. Keeping track of gender can be a tricky task at first with such similar fish, but after reading this article you will have no problem identifying your fish as either male or female betta. Understanding gender in betta fish is not difficult once you understand that they respond differently based on the amount of spikey structures on their bodies called gonads. The trick is knowing what these structures look like in males and females and once you do that, everything else falls into place easily.

How to Tell the Difference Between a Male and Female Betta

Betta fish are often mislabeled in pet stores because many of the general identifiers for male and female bettas are the same, making it difficult for new aquarists to keep track of their sex. Because of this mislabeling, it’s super important to know the difference between male and female bettas to get the proper care for your fish. The easiest way to figure out betta sex is to look at the fish’s belly. Male bettas have a very obvious swelling that looks like a “bubble” bulging out from their bellies.

Females have nothing like this; they are completely flat. If you don’t see a noticeable bubble between the male’s pelvic fin and the tail fin, then you have a female. Another way to identify male bettas is by looking at their fins. The male fins are less rounded than females and they usually have longer and more defined spines. Males also tend to be slightly larger than females, with thicker bodies. Female bettas have a more rounded fin shape and their spines are much shorter and less pronounced.

Differences in Appearance

When looking at the fins of a male and female betta, you can see a few key differences in appearance. The male fin is longer and more rounded than the female fin, with longer and spikier fin rays. Male betta fins also have a thicker base than females. In addition to the fin, the male betta has larger and more pronounced body spines than the female.

The male’s abdomen is also noticeably larger and “bubblier” than the female’s, which is completely flat. Male and female betta tails also have a few notable differences. The male has a larger and rounder tail fin than the female. The female betta’s tail fin is also longer and more pointed than the male’s.

Monitoring Behavior

Female bettas are generally shy, rarely nipping fins or creating aggressive interactions with other fish. Males, on the other hand, are more outgoing and competitive and are more likely to nip at the fins of other male bettas and other fish in the tank. Male bettas are also more prone to creating bubble nests, which are made of a mix of their saliva and mucus. This nest is used to attract the female and create a safe environment to fertilize her eggs. Female bettas don’t create bubble nests, but they do create “nest sites” on the tank floor to lay their eggs.

By Watching Their Habitat Behavior

Another helpful way to tell if your fish is male or female is by watching their habitat behavior. Male bettas are very territorial, and they often create small nests out of their saliva and mucus on plants and decorations in the tank. They also tend to spend a lot of time hovering around the top of the water, while females are usually swimming near the bottom of the tank. If you notice your fish spending most of their time at the top of the water, hovering near the surface, you likely have a male betta.

Female bettas tend to stay near the bottom of the tank, swimming through the substrate and hiding in plants. There are some exceptions to these rules though. Some female bettas like to create bubble nests to lay their eggs, and some like to hover near the top of the water. Some males also prefer to swim near the bottom of the tank, and some males don’t create nests or nests at all.

By Monitoring Reproductive Parts

One of the best ways to tell the difference between a male and female betta is to look at their reproductive parts. The male’s gonads are located near the anal fin, and they are easily identifiable as small white spheres. Females have no gonads, so there is nothing there to identify. This is the best way to tell the difference between male and female bettas, but it is best done during the breeding season. You may also notice that male bettas have a longer gill length than females—although this difference in length is not always noticeable.