Betta Fish Anatomy: Plus Male and Female Differences

Do you have a hard time distinguishing between your male and female Betta? If so, I can understand as it’s difficult to tell them differently. But if you are familiar with your betta fish’s anatomy, it’s not at all challenging. You can better care for your betta if you are aware of its anatomy. 

So, you’ve come to the correct place if you’re interested in learning more about the anatomy of your betta. I’ll give guidelines on each exterior and interior body portion for both male and female betta fish in this section.

Betta Fish External Anatomy

Male and female betta fish have the following external anatomical components. They engage in behaviors including swimming, eating, mating, battling, and others. Starting with the head in a backward motion, let’s separate the essential components and delve further into them.


The two eyes on the betta fish’s heads are on either side. When you look closely, you’ll see that they protrude in the shape of a bubble, with the suborbital region at the bottom and the interorbital region at the top. Popeye is a condition that affects the eyes and manifests noticeable signs. It is simple to see the dark black iris in the middle of their eyes. Depending on the species, the outside section can be whatever color you can imagine.

Bettas struggle and flare up at their owners or their own reflections, which demonstrates their excellent vision. They don’t have eyelids or the capacity to blink as you do, but they do see everything around them in full color. Because they are nearsighted, betta fish can only see clearly up to 12 to 14 inches away. Because of their keen eyesight, which contributes to their inquisitive and aggressive personalities, they’ll scramble to the top of the tank when you place your finger close to the water’s surface or pursue it across the tank (no poking or banging).

Teeth and Mouth

Betta teeth and mouth come in a variety of sizes and shapes. Bettas’ razor-sharp, small teeth let them chew even the most difficult of foods. They are known for biting the tails of other fish, harming the other species in the tank, because of their sharp teeth.

Your Bettas frequently exhibit an irritated or perpetually smug expression due to their upward faces. However, these upward-angled lips carry out the essential tasks of breathing, creating bubble nests, and digesting food that has been deposited on the water’s surface without the need for additional pressure.

In addition to breaking down the meal, their lips are even more important for reproduction. The male Bettas are in charge of transporting the eggs in their jaws once the ladies have laid them at the bottom of the tank to provide a secure habitat. When these eggs are brought to the surface, they should be placed there so they may continue to develop in their bubble nest.


This distinctive feature of betta fish serves as a barrier or shield to safeguard the delicate gills of the fish. It also covers the membrane known as the “betta beard,” which is visible on male bettas and is one way to tell them apart by gender. A betta will flare its gill covers out and lengthen its beard in a show of dominance when it is in combat mode (fighting fish) and trying to seem bigger and scarier.


They also have gills that are utilized to get oxygen out of the water in addition to a highly unusual labyrinth organ that aids in oxygenation. These little, vibrant fish can also take in water with their mouths full and then transfer it to their gills for further oxygen. These multiple approaches are helpful and practical in settings with relatively low oxygen levels.


The external fish scales, or armor, that covers the body can be longer than 2.5 inches. In captivity, a healthy betta fish will have shiny scales and vivid colors. The body is prone to injuries from tank debris with sharp edges and run-ins with other aggressive fish, including other bettas. Horizontal lines may be seen running down the body of a stressed betta, especially in females. These horizontal lines are a sign of development and are often not cause for worry in babies or fry.

Ventral Fin

The pelvic fins are another name for this group of fins, which are utilized for steering. You may observe them being utilized for swimming, stopping, turning, and moving up and down the water. Females have them in significantly lesser sizes than their male counterparts do.

Pectoral Fin

The pectoral fins of a betta fish are probably previously known to you, especially if you own a dumbo or elephant ear betta. The pectoral fins, which are also known as the betta’s ears, move continually as it moves through the water. The size and color of a betta’s pectoral fins depend on its age and species.

Dorsal Fin

The dorsal fin, which is found on top of betta fish, varies in size and form according to the species. Its main function is to support the betta’s stability in the water as it moves along a predetermined path. Your betta fish would find it difficult to move in a straight path if it were absent. This would be especially detrimental in the wild if it made it impossible to successfully pursue animals.

Anal fin

The anal fin is situated along the betta’s underbelly directly beyond the ventral fins, as shown in the image above. The anal fin, which is located opposite the dorsal fin, aids betta fish in maintaining balance as they move through the water.

Internal Body Parts of Betta Fish

The following are some vital organs that Bettas needs to function properly. We advise owners to become familiar with their internal organs so they can cope with any unforeseen damage.


Like people, fish have an esophagus that is connected to their mouth and passes food, water, and air through. Owners must be extremely careful while providing their Bettas with food since even a little cut sustained when eating sharp food bits can have a negative impact on their esophagus.

Gill Arch

Regardless of breed, all Betta fish have a gill arch that joins the gill rakers and filaments. The gills are supported by a curving bar structure called the gill-arch, which is a muscular cartilaginous arch. The oxygen travels down the esophagus and via the labyrinth after passing through the gill arch.


This organ, which is among the coolest features of a betta fish, evolved over time in low-oxygen, stagnant environments. Because they are labyrinth fish, betta fish are categorized as anabantoids. This implies that they can inhale oxygen from the air and absorb it into their bloodstream. Other fish, however, just use their gills to take in oxygen, therefore their situation is different. They are able to live without a bubbler or filter because of this. When using this special talent, they must always be able to reach the water’s surface of the tank.


The liver of a betta fish aids in its internal digestive and storage processes. Their liver releases bile, which is an enzyme, to help food move past the stomach and into the intestine.


Before moving through the intestine, the food that you give your Bettas is chemically processed in the stomach. The fundamental job of the gut is to transfer the nutrients from the food after it has been digested so that the body may absorb them. Prior to the remainder of the meal being transferred to the final phase, it serves as a pathway for nutrient absorption.


Similar to how your tank filter eliminates dirt and unwanted detritus, the kidney cleans out any contaminants in the bloodstream. The kidney maintains a healthy and completely working digestive system, enabling the fish to live longer. When bettas die from conditions like dropsy, they may have renal failure.

Swim Bladder

This organ is found in a unique location along the spine of the body and develops as the betta fish matures. It aids a betta fish in adjusting its buoyancy and depth in the water and has the appearance of an extended balloon. The air within it is controlled to do this. On the outside of your betta fish, perhaps close to the caudal peduncle, you can see it slightly projecting.

Without this organ, they would be resting at the surface of their tank or floating on their side. Swim bladder disease (SBD), which manifests these symptoms, can be brought on by overeating and an undeveloped swim bladder. They are badly affected by SBD in the wild, but they may have rather healthy lives in captivity.

Heart and Stomach

While the stomach of a Betta contains all the little pellets that its owners feed them, the heart performs and regulates the function of blood circulation all through the body. Owners of betta fish should refrain from overfeeding them since they have a small stomach that is about the size of their eye. Further lowering the likelihood of bloating and constipation is the fact that fasting helps with food digestion.

Differentiating Male and Female Bettas Anatomy?

Knowing the differences between male and female betta fish will make it simpler to tell whether a fish is male or female. The internal and exterior anatomy of the betta fish must be understood by all caretakers. These traits will make it simpler to identify diseases and explain which areas are affected. When they are young, male and female betta fish are hard to tell apart, but as they become older, males start to drastically diverge from females. Around the two-month point, betta fish will begin to exhibit varied sexual characteristics.

Anatomy of Male Betta Fish

Males often have larger bodies and longer fins. They seem significantly bigger than females because of their tails, anal fins, and dorsal fins. In captivity, males also have more vivid external pigmentation on their bodies and fins. Additionally, males have a distinctive membrane (operculum) behind their gill covers that are known to fish as their beards.

A male betta fish will flare when he is ready to fight or when he wants to assert his supremacy. The male makes himself appear bigger and more aggressive to others by opening his gill covers and exposing his beard. Unless your betta fish is colorless or has incredibly light coloring, beards are often black in hue. Finally, males are generally more violent than females.

Anatomy of a Female Betta Fish

While their bodies are often slimmer, female betta fish have an average length that is similar to that of male betta fish (up to 3 inches). Females have duller colorings than males, yet they nonetheless have their own unique attractiveness. Additionally, women have wonderful personalities, just like men.

Although it is hardly noticeable and typically doesn’t protrude past the gill covers, females also have a layer (beard) beneath their gill covers. The egg spot or ovipositor tube of the female betta fish serves as a last distinguishing feature. This is the white spot close to the ventral fins’ bases. The eggs will be discharged from this site during mating.


By the end, you should know the organs that distinguish Bettas are their scales, swim bladder, and labyrinths. Given that both sexes have distinguishing characteristics, sex identification is often straightforward, after the study of anatomy. The beard and oviduct are two crucial physical characteristics that pet owners may use to determine the gender of their animal. 

Similar Posts