Betta Imbellis Care Guide – Peaceful Betta or Crescent Betta

Betta imbellis breeding pair.
Betta imbellis breeding pair.

The Betta imbellis, also is known as the Peaceful Betta, is native to Southeast Asia and is one of the most popular wild-type betta fish in the fishkeeping hobby. The name imbellis is Latin for “peaceful.” The imbellis is also known as the Penang Betta or the Crescent Betta and is part of the Splendens complex.


The natural habitat of the betta imbellis.
The natural habitat of the Betta imbellis.

The Betta imbellis occurs primarily in Thailand, Malaysia, Sumatra, and Singapore. Typically, the imbellis is found in sluggish waters, like swamps, streams, ponds, and rice patties. It prefers to stay in the shaded waters, where the bottom floor of its habitat is generally composed of leaf litter and mud. 

The suitable tank size for a Betta imbellis pair is generally is 10 gallons. If you plan on adding other fish to the aquarium, we recommend that you increase the size of the tank accordingly.

Since the species enjoys a shaded environment, we can use plants to create shade. Salvinia and duckweed are good choices. This ensures that your aquarium is not too bright and that your fish is comfortable in their environment. Since the species is used to living in the shaded area, bright aquariums create undue stress, where the fish feels as though they are exposed and vulnerable.

This is consistent with most wild betta fish, who tend to prefer an environment where they feel sheltered and safe.

You can also create places of shelter for your fish within the aquarium. By using plants like Microsorum or Christmas Moss.

This will also increase the chances of reproduction as the male will be more likely to tend to a bubble nest in a sheltered environment.

Of course, as with any other Betta, the imbellis is preferential to slow running water. Ensure that the filter is set to its lowest water flow and if possible attempt to obstruct the flow with a sponge just slow down the speed of the flow.

Water conditions

Betta Imbellis can be sustained in an aquarium whose temperature is within the range of 20 and 28 degrees Celsius or 68 to 82 degrees Fahrenheit. You will need to set up get your betta fish tank with a heater, as this will help you maintain the health of your betta fish. Generally, this also increases the lifespan of the species as they will become less susceptible to diseases and constipation.

Temperature20 to 28 CelciusSpecific GravityFreshwaterTank Size10 Gallons +
pH5 to 7Level of Hardness5-19 °d
Indian almond leaves.
Indian almond leaves.

Betta imbellis and other betta species alike prefer slightly acidic water conditions. A pH value ranging between 5 and 7  is adequate. This can be achieved through the use of almond leaves. They will inject tannins into the water column and provide an aquarium habitat that is more closely similar to the imbellis’ natural environment.

Water hardness should preferably be within the range of 5 to 19 degrees of hardness. 


Brine Shrimp
Brine Shrimp

The diet of the Betta imbellis is wide-ranging, as they are omnivorous. However, their diet should be primarily live food. This includes Daphnias, brine shrimps, bloodworms, and artemia. 

The imbellis is capable of eating flakes and other forms of dry foods, it is recommended nonetheless that their diet consists primarily of live foods. 

Tank mates

Neon Tetras
Neon Tetras, Credits: Wikimedia Commons

Like most species of bettas, the imbellis is not compatible with a community tank. This is due to its territorial and aggressive nature. 

However,  it is possible to pair the imbellis with others of its species. To reduce the chances of in-fighting and aggressive behavior, a larger tank is recommended. This will ensure that enough space is given to the imbellis and reduces the chances of aggressive behavior.

Peaceful, schooling species such as neon tetras are a good choice. Bottom feeders, like plecos, can be tolerated by most betta fish. Always monitor behavior to confirm compatibility.


Male Betta imbellis.

The Betta Imbellis has a tail that resembles the plakat betta type. Typically, the imbellis will have a metallic color, ranging in green, blue, and red.


When fully mature, the Betta imbellis will reach be 5 to 6 centimeters long, or 2 to 2.5 inches. It takes males about a year to become fully mature, while females will reach maturity within 6-7 months. Growth rates are highly affected by overall water quality and diet.

Sexual Dimorphism

Female Betta imbellis.
Female Betta imbellis, Credit: Wikimedia Commons

The Betta imbellis is sexually dimorphic which means that males and females have different appearances. Typically, males are more colourful and have bigger fins.


In general, the imbellis will live between 3 to 5 years. To increase the lifespan of your betta fish, provide an adequate environment for your fish.

Studies show that feeding your fish on a consistent schedule can help increase their lifespan.


The Betta Imbellis are dioecious, which means that both the female and male have different reproductive organs. In the case of the imbellis, the male is more involved than females intending and caring for the fry.

The imbellis are bubble nesters, which means that they create a nest made of bubbles at the top of the water column. During the spawning stage, the eggs are placed in between the bubbles.

To encourage the male to create a bubble nest, tubing can be used on the surface of the water. This can help create an enclosure where the male can safely create his bubble nest. This will prevent the destruction of the nest due to water movement in the aquarium. This can also be done with floatings water plants such as Salvinia and duckweed.

In the nuptial stage of the breeding process, the female will have a paler appearance and will display black vertical stripes betta on the flanks also known as breeding bars.

The male and female will begin their mating dance. This typically takes a few hours and is generally a slow process. For them to engage with each other, the male and female will swim in each other’s vicinity, slowly easing up to each other.


Once they are ready, the male will attempt to flip the female upside down in what is called, the Nuptial Embrace. The goal is for the male to fertilize the eggs of the female as she releases them. Once released, the egg will sink to the bottom of the aquarium. From there on, the male will release the female and fetch the egg. A few minutes later, the pair will embrace again. Generally, the female will release between 20 to 30 eggs. The female may release up to 500 eggs, however, this is extremely rare.

The male will begin to push the female away once the eggs have been spawned. The male will become territorial and become aggressive towards any fish who approach the nest. Females wander away and have no further contribution.

Males will maintain the bubble nest. Eggs may fall from the nest and sink, if this happens the male will pick up the egg and bring it back up to the bubble nest. If the male feels that the nest is in a vulnerable location, he may change its location.

Betta fry in the bubble nest.

The aquarium should then lidded, to ensure that the fry has access to warm and humid air. This important for the development of their labyrinth organ, which is used to breathe air. If you don’t have a lid for your aquarium, you can use plastic wrap.

Typically, the eggs of the Betta imbellis hatch between 24 to 48 hours after spawning. After this, they will remain in the nest with their bodies pointing upwards. The fry will begin to leave the nest after 3 days.

Feeding the fry

You should then begin to feed the fry with small live foods. We highly recommend commercially available fish food for fry or infusoria for newly hatched fry, as their relatively small size prevents them from being able to eat even the smallest of micro worms. Once the fry has grown bigger you may begin to feed bigger size foods. This includes baby brine shrimp, daphnias, fairy shrimp, micro worms, vinegar eels, bloodworms, banana worms, grindal worms, and Walter worms.

The imbellis may breed with other species of bettas, like Betta splendens and the alien Betta.

Where to find it for sale

Imbellis are some of the more popular wild-type betta fish. Local fish stores or betta-specialized stores may have them.

The easiest way to find wild-type betta fish is through an exporter. Typically, from Southeast Asia in countries like Thailand, Indonesia, or Malaysia. 

Frank’s Bettas is a well-known seller for wild betta fish, especially Betta Imbellis. He is from Thailand and you will be required to find a trans-shipper.

In Canada, AquaristsAcrossCanada and Shrimpfever on occasion will have Betta imbellis for sale and other wild-type betta fish. 

IvenBetta is another good seller from Singapore.

Wild-caught Betta imbellis

Betta imbellis Care Sheet

Level of careModerateTemperamentSlightly aggressiveStocking ratio1:1 M:F
Size5-6 cm (2-2.4″)Tank size10 gallons (38 liters)Native originSoutheast Asia
Specific gravityFreshwaterTemperature20 -28 °C (68-82.4°F)pH5-7
Degrees of hardness5 to 25Level of availabilityUncommonDietCarnivore


SpeciesBetta imbellis


Betta imbellis – Crescent Betta — Seriously Fish ” Betta Imbellis – Crescent Betta — Seriously Fish”. Seriouslyfish.Com, 2020, Accessed 30 May 2020.

Kusrini, E., Rahmawati, R., Murniasih, S., Kusumah, R. V. and Prasetio, A. B. Kusrini, Eni et al. “GROWTH AND COLOUR PERFORMANCE OF THE CROSSBREED MARBLE STRAIN Betta Splendens AND Betta Imbellis”. Indonesian Aquaculture Journal, vol 10, no. 2, 2015, p. 101. Agency For Marine And Fisheries Research And Development, doi:10.15578/iaj.10.2.2015.101-112. Accessed 30 May 2020.

File: Betta Imbellis (Female) 20100511.Jpg – Wikimedia Commons”. Commons.Wikimedia.Org, 2010, Accessed 1 June 2020.



The Whiteseam Fighter of Southeast Asia

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