Betta imbellis, often referred to as the ‘peaceful betta’ or ‘crescent betta’ is one of the most popular wild bettas among the splendens complex. It’s green color with bright red accents make it’s popularity well deserved.

However, the Betta imbellis remains a hidden gem for most aquarists.

When most people think about Betta’s they see the classic Betta splendens, with huge fins and intense coloration all over the body. In order to keep these fish successfully you will need to learn more about how to care for them the best way.

No time to read? Some quick facts.

TemperamentA cheerful fish who is peaceful towards most other fish if housed the right way. Males can be aggressive.
AppearanceIridescent green-blue scaling all over the body with a deep-red crescent on their tail.
TankWell planted. At least 4 gallon for a single male, 15 gallon for a pair
FoodFrozen and live foods like mosquito larvae, daphnia, BBS, or bloodworms. Or dry pellets/ flakes.
WaterpH: 5-7.5 Temperature: 72°-80°F


Betta imbellis appearance
Photo by Frank Sriboribun

Betta Imbellis is a green fish with red-black ventrals and a round eclipse on the tail. In some cases under the right LED led it can colour up blue, while under a more warm light it has an emerald green color. Like all betta fish, the males are the most appealing and have more expressive fins, as well as colours and temperament. Females have a lighter brown color and are better camouflated.

● Tail and eclipse

The name ‘crescent betta’ also originates from the intense red-colored eclipse on the tail. This eclipse can either form an almost perfect crescent, or covers the back part in a rounded form.

● Scaling

Emerald-green scaling is spread over the whole body on top of a brown-black base. The only exception is the top or back, which is a dark tint used as camouflage for predators like birds (or recently also humans) who hunt from the top.

Cheeks are mostly covered with a black stripe trough the middle. Although some strains also have full-covered cheeks.

● Size

While species like Betta mahachaiensis can sometimes grow up to 2.5-3 inches, this species is along with Betta siamorientalis the smallest of the splendens complex. 

Males can grow up to a good 2 inches and females mostly stay smaller and don’t get bigger than 1.9 inches.

● Ventrals

Ventrals around ⅓ of body length are mostly red. The sides are black and sometimes a part is white. When flaring, males will move their ventrals in order to get the attention of female or opponent males.

Betta Imbellis is part of the splendens complex and lives in shallow waters like rice fields or swamps in Malaysia. Water is mostly on the sour side and has a pH in between 4 and 7 due to its bottom. 

Betta imbellis in the wild

Wild Betta habitat in Thailand
A wild betta habitat in Thailand. © Frank Sriboribun

Originally, betta’s were caught by people to make them fight each other. Imbellis is a less popular fighting fish than Betta splendens, which has been bred to various fighting strains like Thai fighter fish or even the classic domestics. 

However Betta imbellis has been bred out of its original wild forms for many years and many strains have been developed.  

Wild betta distribution Thailand and Malaysia

Betta imbellis care

● Tank setup

The ideal tank size for one male is from 15-40 litres (4-11 gallons). If you want to keep Betta Imbellis as a pair (more on that below) you should look into a tank of at least 15 gallons or 80cm. A low water level is preferred. 

The perfect tank for wild bettas
Photo by Peter Luijstens

Cover your tank with as many plants as possible reaching up to the water surface. It makes them feel more safe, betters the water quality and is great for your bacterial and biological balance. If you plan on keeping a pair or harem, those are even more important since females can hide and avoid fights.

Wondering what plants to use? Good plants for wild bettas are those who do not need a lot of light to survive. Think of java fern, java moss, floating plants like frog bite and anubias.

Another great addition for your tank is driftwood. This brings extra shelter for your betta fish and adds a nice extra natural touch. For tannins I highly recommend using catappa leaves. These help prevent diseases, lower your pH and add a dark tint to your aquarium, just like in the wild habitat. A dark soil is recommended in your tank. It makes the colors of your fish stand out better and a dark soil makes them feel more safe.

In terms of filter, it’s really up to you what you prefer. If you decide to use a filter, use a sponge filter or one with a low flow rate. Betta’s do not like fast flowing water. They tend to do just fine in low-tech setups too but for your plants a filter is a nice addition. 

A lid is absolutely necessary. Betta’s are great jumpers and you should have a hole-free lid in order to prevent them jumping out of your tank. 

● Food

An Alien Betta feasting on bloodworms

Offer meat-based foods like mosquito larvae, bloodworms or daphnia. Some individuals can be picky towards classic dry pellets or flakes and so you will need to experiment what works best. Offering different kinds of foods helps providing your fish with the right vitamins and minerals.

Live foods are great to get them to spawn and make them fatter. If your betta won’t eat, try offering live foods and almost all the time natural instinct will take over and your fish will start to eat.

● Water parameters

Don’t break your head over your water parameters. They can handle a pH of in between 5 and 7.5 which is where most tap water is at. As long as your water is clean and has a good biological balance with no harming contained in it your Betta imbellis will do fine. 

In the wild, the pH is  between 4.5 and 6.5 caused by the the bottom and organic materials. This causes Wild caught fish to be more sensitive towards water parameters, so if your seller says they are you should look into lowering pH to under 6.5.

As of temperature, anything between 72° and 80° F is fine (22-27°C).

Is Betta imbellis a peaceful Betta?

If you are reading into getting Betta imbellis, there is a big chance you came across it’s common name ‘the peaceful betta’. This is referring to its nature to be more tolerant towards each other than classic domestics, who have been selectively bred for aggression (among other things). The name “imbellis” even originates from Latin and means peaceful. 

Although it is certainly true that Betta imbellis can be placed together if housed right, there are a lot of factors to take into account when thinking about keeping a pair. First off, wild betta’s, and so Betta imbellis, can get just as aggressive towards each other as domestics. They are faster, since their fins allow them to swim more, so chasing a female is easier for the male too. Fights are unavoidable with all betta’s, it’s just the nature of the species. If your tank is too small this will result in fights, and if not separated, into the male killing the female. On the other hand, if you can guarantee the tank will be big, with lots of plants you will have a decent chance in housing a pair or even a small harem together.

Here are some tips to accomplish that.

Tank – For permanently housing your Betta imbellis together you should look into a tank of at least 15 gallon. Preferably a low and long tank, since a low water level offers more hiding spaces and better matches their natural habitat. In a 20 gallon long, you could house even a small harem of three females.

Plants & hiding material – As of your tank, you really can’t have enough plants. Make sure to have every 20cm at least one plant. Betta’s are used to living in rice fields or small pools with a lot of vegetation. Plants create small places in between and offer hiding. Great for hiding are hardscapes like driftwood or rocks (do not put in chalk stones, they will higher your pH). And ofcourse Catappa leaves. Numerous times I have seen females hiding from the male unther those. Apart how great they are for things like diseases they provide great hiding.

A watching eye – Even with the best tank things can still go wrong. Always watch how your fish behave. Every fish is different, in some cases it goes fine, and in others it ends bad. Always be prepared to seperate, if necessary. An important thing to say is that if you choose to keep multiple Bettas together they will most likely start breeding one time. To prevent this you can add a sponge filter wich creates just enough flow to prevent bubble-nesting.

Breeding Betta imbellis

When it comes to breeding, this species doesn’t differ that much from domestics. If you condition them well, Betta imbellis is a species that is fairly easy to breed.

  • Choosing your pair

Never inbreed to another wild betta species or to domestic Bettas. Always pair up a Betta imbellis to an imbellis female. Why? Betta imbellis are becoming more popular, but so are the hybrids. I have seen a lot of fish labelled as imbellis, who are actually a hybrid between different species. Unfortunately this makes our beloved real wilds slowly disappear and makes it hard to find real imbellis. So if you want to breed, choose two fish that are from the same species. 

  • The breeding tank

First, set up your tank. A 7-12 gallon will do fine. For the fry and the male a low water level is the best. The female can hide better and the male will have to work less to put eggs and fry back in the nest. Put in as many plants as you can and add catappa leaves. No filter required. After a week of cycling put in the male, he will build a bubble nest where the pair will spawn. 

  • Preparation

Put the female in a bottle and let them see each other. In order to prepare them, feed live foods up to two weeks before. 

After one to three days you can see if your female is ready to spawn. Does she have strong vertical stripes, a big belly and a visible egg-spot? Then it’s time to spawn.

  • Spawning

Always be very careful for the first hours of releasing. It is normal the male chases the female for a bit, but not if they are fighting heavily. I find that it can take upwards to 3 days for them to spawn. This is why plants are so important. It is normal a spawn doesn’t happen in hours and in the meantime the female must be able to hide from the male if necessary.

After spawning directly remove the female, and when the fry swims horizontally remove the father. Fry can be fed baby brine shrimp or small micro-organisms.


Betta imbellis is a great and wonderful species to keep in your aquarium. They are more peaceful than the classic domestic bettas if you can house them in a good tank. If you are searching for a new challenge or adventure this fish might be the perfect fit for you. It is great for beginners and experienced keepers but needs good preparation in order to keep them successfully.
When given the right care and good tank, you will have beautiful, healthy and peaceful fish.

What do you think about this beautiful fish? Let me know in the comments!