Betta Fish Anatomy

betta fish anatomy infographic

As I have mentioned before, the fighting fish has a special organ called Labyrinth.

This special organ allows them to breathe atmospheric air as we do.

This special organ allows them to live in bad water conditions. Even if the water is polluted and low in oxygen.

Their native habitat is puddles, ditches, slow-moving streams and rice paddies which are found in Cambodia and Thailand.

The average lifespan for the fighting Fish is around 2 to 4 years and grow up to 2 to 2.5 inches.

External Betta Fish Anatomy

The betta fish have two eyes. Their eyesight is very good and this is used for their fighting nature.

The effectiveness if their eyesight is about 12 to 14 inches away.

If you have noticed, when your finger is on top of the aquarium, they are very responsive and try to play catch up with you.

They see everything in the full-color spectrum but near-sighted.

They are built to for combat and fighting that’s why their nearsightedness is only within 12 to 14 inches. Betta Fish are very curious in nature and very intelligent little fish.

Historically, the Siamese fighting fish have been used in Asian countries specifically to a sport which is very similar to cockfighting.

The betta fish that are used for fighting specifically have shorter fins’ and super aggressive.

The male betta fish have very colorful fins’ and because of specialized breeding, they have the: half moon, double tail and crown tail varieties. When they betta fish age the fins’ tends to be longer when it will lose it. It does grow back but it will look the same as the original. This loss of tail actually rejuvenates the fish.

On the other hand, the female betta fish, as of the same size as the male. It normally has shorter fins’. The original female betta fish have very dull fin colors. But because of selective breeding, the female betta fish now has also bright and very showy fins’ and comparable to the male betta fish.


As you would have noticed that the Betta fish are small and seems to be very harmless. But actually, if you are of the same size as them it would be terrifying!

Their mouth is full rows of very sharp tiny pointed teeth. The strength of their jaws in proportion is more powerful than of the great white shark.

They used their sharp teeth to break down the food to aid ingestion and also they use it for fighting and nipping their enemy.

It is also a surprise that when they are busy about carrying the eyes into the nest, none of the eggs are destroyed.

Betta Fish are carnivores in nature so the pointed sharp teeth help them break down the food. They are very good in controlling the population of mosquitoes where they eagerly eat the larvae s at the surface of the water.


This feature acts as a protective cover or barrier for the gills. Did you notice that sometimes they flare and showing its aggressiveness?

They are similar to cockfighters when they are fighting the operculum is always flaring out to show dominance and makes it look bigger.


The betta fish gills are similar as compared to other aquatic creatures and other fishes.

Did you notice they sometimes just hang on the fish tank decor or plants? They are using their gills to breathe air through water.

It is very nice for the betta fish to have the gills and also the labyrinth for surviving low oxygen water conditions.

Ventral Fin

This is also named as the pelvic fins’. They are primarily used for steering to left, right, up and down.

The ventral fins’ are smaller on female betta fish as compared to the male betta fish.

Pectoral Fin

These fins’ are always moving and is used when they are navigating in the water. They look like ears.

The fins’ come in different size and shapes also have different colors on variations of the betta fish.

Dorsal Fin

This also comes if different sizes and shape on the different variants of the betta fish.

If without this dorsal fin the betta fish would just be traveling in a very awkward straight line.

This fin happens to stabilize the navigation of the betta fish when trying to attack a prey.

Anal Fin

This fin also helps in maintaining stability when the betta fish is navigating the water.


This is common for all the fishes. It contains the fish scales or Armour of the fish. As mentioned previously the betta fish can grow up to 2 to 2.5 inches in body length.

If the betta fish is healthy it will noticeably exhibit vibrant colors and very healthy looking scales.

The body, of course, gets injured if the betta fish goes to the arena to fight.

If the betta fish is under a lot of stress then there will be a noticeable horizontal line on the body which is more evident on the female betta fish.

The betta fry or babies show horizontal lines when it is growing which is of course not of concern.

Caudal Fin

This is primarily used for propulsion in the water. For the betta fish that are sold in pet stores have long beautiful caudal fins’ which come in many variants as well and come in different sizes and shapes.

Most of the betta that is sold have long and very elegant caudal fins’.

As opposed to the wild, the caudal fins’ are shorter and not that brightly colored otherwise they become the prey and will eventually get nip by other fishes or predator.

By the way, it is also important to sparingly check once in a while for the signs of fin rot.

Internal Betta Fish Anatomy

It seems that the Fighting Fish almost has the same as the internal organs as we do. The Siamese fighting fish internal organs are different and shapes as compared to humans. But in essence, they have the same functions and performance.

As you have noticed even the names are the same such as liver, heart, intestine, kidney, esophagus, anus, and testes.

I will try to explain and describe the functions of the internal organs.

There are no known pictures of the internal betta fish anatomy aside from this which was created by the artist as indicated below. All rights reserved to the author’s rightful picture.

Internal Betta Fish Anatomy


This has the same function as humans. The food is passed through the mouth after the food particles are broken down by the sharp teeth of the betta fish. The esophagus is connected to the different organs.

Gill Arch

This is a bony structure wherein the first and second works in synergy for the air to pass from the esophagus.

All gill elements such as filaments and rakers are all attached to the gill arch.

This is where the air goes through the cavity and towards the labyrinth for the oxygen needed.


As mentioned many times that this is the special organ that the betta fish possess. This organ has evolved because of the low oxygen in the rice paddies, ponds, and slow-moving streams. This organ extract atmospheric air. The betta fish can survive also in very polluted and muddy waters in the rice puddles.

Even when the water is full of ammonia and nitrate the betta fish will still be able to survive. This kind of fish is very hardy

That’s why it is recommended as a starter fish which is awesome to look at and especially with its brightly colored magnificent fins’.

You have to make sure that the aquarium is not too deep so that the betta fish will be able to gulp air from time to time on the surface.


This is the same function as humans. These organs store fat and filter the food. The liver secretes the bile which can be compared to humans too.

This organ is used to process the food through the stomach and goes to the intestine.


Same functions as humans. This organ where the nutrients are absorbed by the body and used for fuel. The intestine absorbs the much-needed building blocks like vitamins, protein, fiber which is needed for survival and growth on the betta fish.


This organ removes the impurities from the bloodstream.

Swim Bladder

The bladder is the equalizer in the balance and buoyancy of the betta fish. Without this, the fighting fish cannot adjust the depth navigation.

The air is adjusted inside the bladder enabling it to go up and down.

This is an essential organ so that they won’t be seen floating on the aquarium.


This is the reproductive organ in male betta fish


This is the organ that holds the waste the kidney which has been filtered from the betta fish.


This is the area where the waste gets out from the betta. If there is a stringy poop hanging then it is a sign of overfeeding and possibly constipation.

It would be wise to get the proper food for the betta fish and just feed it once a day with a few pellets.


This betta fish heart is used to pump blood throughout the body and of course, this organ maintains the blood pressure.

You would notice that betta fish have a big heart which you can see by their fighting nature.

Differences Between Males and Females

The differences between female and male betta cannot be distinguished when they are still in infancy.

You will only see a difference when the betta fish is about 2 months of age.

I will point out the main differences between the male betta and the female betta fish.

This is of important to know the difference if in the future you would like to breed fighting fish and maybe if you wanted to go into this business.

Breeding bettas can be a small lucrative business on the side since they are very hardy and once you get the hang of its, it will be very rewarding.

It is essential to start studying the differences in male and female betta.

Male Betta Fish Anatomy

The male betta tends to have a bigger thicker body and longer fins’.

Their anal and dorsal fins’ appears to be much larger as compared to the female betta.

It is very easy for one to see that the male betta fish has the beard under their gill covers.

They normally exhibit more vibrant colors on their body and very brightly colored fins’.

Of course, the make betta is much more aggressive as compared to the females. Bear in mind that they are the cockfighting version in Thailand and Cambodia.

It is only the male betta fish that when he is highly aggressive he likes to flare and open his gill overs exposing his beard to show that he is in business to win a fight.

Female Betta Fish Anatomy

The female fighting roughly has the same body length as compared to the male betta.

The body is thinner and the fins’ are not very brightly colored and duller body color.

They have a small beard but it never extends and doesn’t show.

As you have noticed on the picture there is a white spot which is near the base of the ventral fins’. This white spot is where the eggs are released during mating.

In scientific name, it is also called the ovipositor tube.