Betta Imbellis (Peaceful or Crescent Betta)

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One of the six betta kinds that make up the Splendens complex, Betta Imbellis is also referred to as the Crescent Betta or the Peaceful Betta.

Contrary to what is said in other sources, the Betta Imbellis is not actually a peaceful species of betta.

People used to keep these bettas for one purpose alone, which was to compete in local arenas, and that was to battle against one another.

Those who are interested in fish fighting often train their fish to be aggressive.

Fish fighting is a tradition that has been practiced across all wild species of Betta fish in Thailand for many generations.

The extinction of the species was due in large part to the failure of conservation efforts to take place while fish fighting was still commonplace.

Not to mention the fact that natural ecosystems have been eradicated in order to make way for new developments.

People have just begun breeding them in recent years with the intention of bringing the species back from the brink of extinction.


The green Betta Imbellis has reddish-black ventrals and a circular eclipse on the back of its tail.

In certain circumstances, when illuminated by the appropriate LED, it can take on a blue hue; nevertheless, when viewed in a warm light, its color shifts to that of an emerald green.

The male betta fish, like other betta fish, are more beautiful than the females because their fins, colors, and personalities are more vibrant and expressive.

The coloration of the females is lighter brown, making them more difficult to spot.

The name “crescent betta” comes from another aspect of this fish’s appearance: the tail has a vivid crimson eclipse.

This eclipse has the potential to either take the shape of a nearly flawless crescent, or it may cover the back part in a rounded form.

A black tint on the top or back serves as camouflage against predators, such as birds that attack from above.

The majority of the cheeks are covered in a dark stripe that runs down the center. There are some strains that have cheeks that are completely covered.

This species, along with Betta siamorientalis, is the smallest of the splendens complex.

Males have the potential to reach a length of approximately 2 inches, while females often remain smaller and do not grow any further than 1.9 inches.

Around one-third of the length of the body, the ventrals are predominantly red.

The sides are mostly black, but there are some white patches here and there.

Betta Imbellis care

Betta Imbellis Diet

In their natural environment, Betta Imbellis eat live insects as well as the larvae of other insects and invertebrates.

Although there is evidence that the fish are carnivorous based on their short digestive tracks, some sources claim that the fish also feed on leaf litter after it has fallen.

When food is short, these fish may resort to eating plants, but the plant matter they consume will not provide them with any nutritional value.

There are three distinct kinds of betta food that can be given to Betta Imbellis that have been raised in captivity, and you should never give just one of these to your pets.

Live Food

The most nutrient-dense meal you can give your bettas is live food.

Your bettas will be hunting similarly to how they would in their natural habitat if there is live food available.

In addition to receiving a plethora of proteins, the process of finding the prey is beneficial to the fish.

Ideally, you should offer different foods so they don’t get bored.

Offer daphnia, mosquito larvae, brine shrimp, and tiny insects as alternatives. Additionally, as an occasional treat, you can give your bettas blood worms to eat.

Just be aware that because blood worms contain a lot of fat, you should only feed them occasionally.

The cost of a live food diet is its sole drawback, although it is by far the best diet for Betta Imbellis.

Frozen Food

Frozen foods are a fantastic substitute for live foods.

With the exception of the thrill of the chase, these treats provide the same advantages as feeding your bettas live foods.

Frozen meals are less expensive and substantially less prone to contamination than live foods and they provide the same amount of nutrients.

Sinking Pellets

There is a possibility that your betta may not enjoy eating pellets, but some do.

Pellets, in comparison to live foods and frozen foods, come with the benefit of being more wallet-friendly.

Having said that, you will want to select pellets from high-quality brands that contain at least 30 percent crude protein when you are making your purchase.

Checking the ingredients list will help you steer clear of any unknown fillers.

The fact that tropical fish flakes typically contain vegetable and plant fillers is the primary reason why we do not advocate purchasing them for Bettas.

Although these components are suitable for consumption by omnivores, your Betta Imbellis will not receive the necessary nutrients from them to achieve its full growth potential and keep its beautiful coloring.

Water Parameters

They favor waters that are shaded by plants of all kinds, including marginal plants that hang over the water’s edge, floating plants, and submerged plants.

Because of seasonal changes in the water bodies they occupy, substrates may differ depending on the time of year.

Substrates in their environment might range from dirt to mud to decaying leaves.

Betta Imbellis prefers a water temperature of between 72 to 80 F.

PH should be in the range of 5.5 to 7 with a water hardness of 5 to 19 dGH.

Tank Requirements

You should consider a tank that is at least 10 gallons in size to house your Betta Imbellis.

A low and long tank is ideal, as it more closely resembles their natural habitat and provides more hiding places.

You could even fit a small harem of three females in a 20-gallon aquarium.

You just can’t have enough plants in your aquarium.

Bettas are used to living in small, vegetated pools or rice fields. Plants provide hiding spots. 

Hardscapes like driftwood, rocks, and of course, Catappa leaves, are also excellent for hiding. These leaves are excellent for combating infections.

Space and freedom to form territories should be prioritized in the aquarium.

Wild bettas love to have tannins in their water so this must be supplied to mimic their natural habitat.

To further mimic their native environment, you should scatter stems, roots, and branches throughout the aquarium.

These fish love to jump so a tight-fitting lid is essential. They do need to gulp air from the surface so make sure that there is sufficient space between the surface of the water and the lid of the tank.

Water flow should not be too strong as they prefer calmer waters.


As long as you feed your Betta Imbellis with a varied high-protein diet then you can expect them to live in captivity for around 4 years.


Latin for “calm,” the word “Imbellis” is actually somewhat misleading.

Thai natives who have been breeding and raising Betta Imbellis for at least a decade know full well that these fish are anything but peaceful.

Just like the other Splenden complex species, the Betta Imbellis is predisposed to be aggressive and territorial when confronted by members of the same species or if their tank is not big enough.

Tank Mates

Betta Imbellis is just like any other species of Betta in regard to tank mates.

A male should never be kept with a single female or another male.

Tank mates can include neon tetras, small loaches, plecos, red-tail rasboras, large shrimp, and corydoras.

Wild bettas can be housed together as a group but only with a ratio of 1 male to 5 females, you should NEVER have males together in the same tank! 


Breeding the Betta Imbellis is not too difficult, especially if they are already kept in pairs.

They use a bubble nest, like the majority of betta species.

The male will construct this bubble nest at the water’s surface before spawning, frequently utilizing plants as an anchor.

After the male has fertilized the female’s eggs, the two will transport the fertilized eggs into the nest and place them inside the bubbles.

The female can be taken out of the tank once the eggs have been laid and placed in the nest.

The eggs will be cared for by the male Betta Imbellis until they hatch, which typically takes one to two days.

The juvenile bettas won’t be able to swim independently for another two days.

In order to prevent any of the fry from being eaten, it is preferable to move the male fish to another tank as soon as the fry starts to swim horizontally.

For the first several days, the fry can be fed liquid food before being switched to baby brine shrimp or microworms.


Betta Imbellis can be more peaceful than other betta species but they are still bettas so care needs to be taken.

Although the Betta Imbellis is not nearly as showy as the more common Betta splenden, it may be kept with other fish, including other Betta Imbellis, and will live a long and healthy life when given the appropriate amount of space and correct diet.

This betta can be the ideal fish for you if you are searching for one that is low maintenance but yet has a lively personality, as it possesses both of those qualities.

Check out other articles about Betta fish.

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Irma Bense is the founder of She has over 42 years of experience in keeping fish.She has kept both freshwater and saltwater fish through the years.She has extensive knowledge in breeding numerous species of fish from Show Guppies, Cory Catfish, German Blue Rams to Apistogrammas.You can learn more about Irma on the 'About' page.

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