Betta Macrostoma Care Guide: Tank Setup, Size & Breeding

When it comes to exotic and uncommon fish species, the Betta Macrostomas is unquestionably one of the rarest and exotic. Several fish species are regarded as unusual and exotic in the world of fish keeping. These fish are notoriously tough to come by and keep as aquarium pets.

However, suppose you are capable of supporting these fish in the appropriate conditions. In that case, your aquarium will be an envy-worthy one. Most fishkeepers consider it to be the most exquisite species of fish to have in their tanks. This article talks about everything you need to understand and know to keep your betta macrostoma perfectly healthy and well-taken care of.

What Does the Betta Macrostoma Fish Look Like?

The betta macrostoma is a species of fish that is also referred to as Brunei Beauty. Why? Essentially due to its striking orange color.

Betta macrostoma

While this is the most characteristic feature in the appearance of the betta macrostoma, there are other identifying factors as well. To begin with, the betta macrostoma differs from its other betta counterparts in the appearance of its fins.

In contrast, most other betta fish have highly flamboyant fins; the betta macrostoma species sports slightly subtler fin structures.

The spot fin betta is a pretty large species of fish that can grow three and a half to four and a half inches long. They have red, brown, white, and black colors and small, spherical fins and broad jaws.

Another characteristic that highlights the rarity of the betta macrostoma species is their large orifice or mouth opening. True to its name, the macrostoma does have a large (macro) mouth (stoma).

This species of fish generally use their mouth for breeding and preying on large sea creatures.

In fact, an aspect of the betta macrostoma breeding ritual is the show-off of the size of their oral openings in an attempt to woo a female betta macrostoma to mate with him.

All of the fins have black patterns. There is one black vertical marking on the cheek scaling, and the mouth is completely black.

What is the Average Lifespan of the Betta Macrostoma?

Much like their betta counterparts, the betta macrostoma species also live up to five years of age on average.

However, with the right care and living environment, it is possible for this breed of betta fish to live as long as ten years of age.

Distribution & Natural Habitat of the Betta Macrostoma Species

Brunei and northern Sarawak in Malaysia are home to the Betta Macrostoma. It typically lives in streams and ponds in its natural environment, which essentially comprises rainforest and dense foliage.

The water is shallow, measuring between one and two feet deep. Unlike the habitat of the well-known betta splendens complex species found on mainland Asia, these pools frequently have some current running through them.

Betta Macrostoma: Breeding The Dream Betta

Because the naturally occurring substrate is made up largely of organic materials, such as leaves, the pH of their natural water habitats is low.

The pH of catch sites is typically between 4.4 and 5.7, which necessitates using Indian almond leaves for your betta to create a natural setting. Predators are protected by the leaves and branches on the bottom.

Agricultural growth has resulted in the rapid destruction of its native habitat, resulting in a sharp population fall.

Ecologists thought that the betta fish had gone extinct in Brunei; nevertheless, in the 1980s, people discovered the betta fish in several sections of the country. It is still classified as an endangered and vulnerable species today.

In fact, it might be considered illegal to catch and have betta macrostoma as pet fish in tanks in some regions of the world.

The majority of Betta Macrostoma offered to fish-keeping enthusiasts are from the Malaysian waters or fish that have been targeted bred for fish-keeping purposes in controlled environments. 

Aquarium Care for Betta Macrotoma Fish

Betta Macrostoma Care Guide

Tank Sizes for Betta Macrostoma

You should remember that your betta macrostoma fish needs at least a 20-gallon tank capacity. If, however, you wish to house multiple betta macrostoma in the same tank, you should opt for the recommended 50 gallons tank capacity.

The reason this species of fish needs this large a tank is that it is a pretty active type of fish that prefers space to swim around. Furthermore, the ideal aquarium size allows a betta fish to reach its full growth potential and lifetime.

In the perfect tank conditions, the betta macrostoma can even reach a maximum length of 4.5 inches, despite the average of about three and a half inches of length.

Also, by providing your pet betta macrostoma with these tank conditions, you can extend its lifespan beyond the average of about three to five years of age.

Because betta fish have a remarkable ability to jump out of the water, the aquarium must have a securely fitted covering or lid.

While you won’t generally face the issue of your betta macrostoma jumping out of the water in proper living conditions, it is still better to be prepared for the possibility. The appropriate water conditions your betta macrostoma needs have been discussed in the next section.

Ideal water conditions and temperature for Betta Macrostoma Fish

A temperature range of 75-79°F (24-26°C), a pH of 6-7, and a water TDS of 1-10 DKH are all appropriate aquatic conditions for the Betta Macrostoma species of fish. The pH required for the Betta Macrostoma is substantially higher than the normal tap water pH.

Therefore, you must take care to ensure that the pH of the tank water does not exceed seven units and is maintained consistently with as little variation as possible. 

If, however, the pH does increase in your betta macrostoma’s tank, there are a variety of methods for lowering pH and maintaining it at a level that mimics the ideal natural conditions that wild betta macrostoma live in.

The first technique is to provide driftwood, which will gradually emit tannic acid, reducing the pH. Driftwood also serves as a natural habitat for betta fish. Adding peat moss or almond leaves to the aquarium is another good approach to lower pH.

Bear in mind that the Betta Macrostoma is sensitive to nitrates and ammonia compounds, and it dislikes water chemistry changes. As a result, striking a perfect balance between cleanliness and specified water characteristics is ideal.

Living plants, sponge filters, and partial water changes are the three main methods for accomplishing this goal.

Lighting needs for your betta macrostoma

Low or dim illumination is suggested for the Betta Macrostoma. Thick rainforest produces a natural canopy overhead in the Brunei and Sarawak regions. At the same time, the lake itself is also covered with plants, providing additional shade from the sun.

The betta fish will grow stressed if the aquarium illumination is excessively bright and direct. Low lighting, floating plants, and plenty of driftwood or clay pots for places to seek refuge or shelter will help to create a serene environment.

Purchase an aquarium with shaded glass or apply a dark background to three sides of the tank to reduce the amount of sunlight entering through the sides.

Betta Macrostoma Tank Mates

As far as keeping tankmates for your betta macrostoma is concerned, you can, but with a catch. The fact is that the betta macrostoma is a pretty calm species of fish compared to its splendens counterparts.

However, male betta macrostoma can be aggressive, at times, to other male betta macrostoma that intrude on their territory in the water.

However, these shows of aggression and conflict should be minimal if you have provided them with an appropriately sized fish tank.

Although gentle, the Betta Macrostoma is incompatible with other fish species. They may attack and try to consume it if they are placed alongside other smaller fish.

Betta Macrostoma will become disturbed or stressed if they are kept among larger fish. It’s ideal to only pair the Betta Macrostoma with the opposite sex Betta Macrostomas; a male and female who have organically paired before being placed together will fare incredibly well.

Maintenance of tanks for Betta Macrostoma fish

One thing to note when adding items to your betta macrostoma is the helpfulness of living plants in its tank. The reason is that living plants will help to enhance water quality by absorbing ammonia and nitrates and further oxygenating the water.

You should also select a sponge filter for your fish tank because it allows good bacteria to grow while providing slow-flow filtration. This is very similar to the natural habitat of slow-moving rivers and streams.

Every week, you should make it a point to perform a partial water change. Sticking to a 25 percent water change is a good and reliable technique to maintain clean conditions in the aquarium without severely altering the water chemistry.

Many fish keepers choose to take advantage of the fact that the Betta Macrostoma does not require the substrate to make cleaning their fish tanks easier.

Having said that, adding large or medium-sized gravel to the tank would improve your tank’s living conditions for your betta macrostoma fish.

Breeding Macrostomas

A tank set up for breeding your pet Betta Macrostoma does not necessitate a significant departure from an ideal tank setup. The greatest setting will be softly lit and filled with driftwood and real plants.

This will make the betta fish feel more at ease, which will increase the odds of a successful breeding time. Furthermore, having a slow-flow filter and no substrate is beneficial since it keeps the fish fry safe.

Some breeders recommend keeping a breeding tank at a little warmer temperature than normal to simulate “breeding season” in the wild, which occurs in late winter and early spring, and keeping the pH below 6.

Prior to being placed together in an aquarium, the male and female fish must find their natural mating; only then will they cohabitate harmoniously.

This can be accomplished by grouping one male with a pair of females and patiently waiting for the male to choose a female.

Many fish keepers who have schools or groups of Betta Macrostoma notice these pairings without isolating one male with a group of females see these pairings occur without separating one male with a group of females.

After the male and female have successfully bonded, the female will begin the breeding process by flaring and fluttering her fins in front of the male in a betta fish dance. The male will reciprocate in kind, opening its mouth wide as well.

This behavior will be mirrored by the female. Following that, the male will wrap himself around the female in an embrace until his pelvic fin lands on her lips, causing the female to release her eggs, which the male will fertilize.

Betta macrostoma prefers mouthbrooding, unlike other betta fish. Essentially, a mouthbrooder will pick up the eggs in his mouth, and the female will assist by scooping up the eggs and spitting them into the male’s mouth.

Having done that, the male betta macrostoma will incubate the eggs for up to a month once he has successfully collected the eggs. He will not eat and will spend most of his time resting.

The incubation period must be as quiet as the breeding and spawning processes; if the male grows upset, it will swallow the eggs. It is recommended that the female betta be removed from the tank so that the male is not endangered by her presence.

The Betta Macrostoma fry will be released after 30-35 days. They’ll be about 0.2 and 0.3 inches long. The young fish are vulnerable to being eaten by their parents, mainly because they are so small.

The fish fry should be protected and safe as they would be in a natural habitat if there is dense plant cover; nevertheless, it is also acceptable to remove the parental fish from the aquarium.

Betta Macrostoma Diet

The Betta Macrostoma is an omnivore who enjoys a diet that is full of protein. Even if they are bred in artificial environments, most Betta Macrostoma fishes don’t enjoy a commercially available pellet-based diet.

Rather, your betta macrostoma pets are more likely to enjoy meals that include live prey fish or frozen seafood such as shrimp.

Other common animal-based foods that you can feed your betta macrostoma with are bloodworms, white worms, blackworms, mosquito larvae, crill, and so on. However, food in dry flakes or pellets is convenient and can give a nutritionally balanced source of nutrients. 

Sexual Dimorphism in Betta Macrostoma

Sexual dimorphism essentially means that the male betta macrostomas look different compared to their female counterparts.

Males grow larger, sport a thicker skill and longer fins, and a vibrant color scheme on their scales compared to female betta macrostomas. 

How Much Does Betta Macrostoma Cost?

The Betta macrostoma fish being one of the most exquisite species of fish in the pet market, a betta macrostoma can cost as much as $150 per individual.


Adding betta macrostoma to your collection of pet fish will certainly add a feather to your metaphorical hat. But you must only buy them if your country or region permits it by law and ensure the high levels of care they need to thrive.


Which bettas macrostomas are more aggressive?

Male betta macrostomas show more aggression than their female counterparts.

What do betta Macrostoma eat?

Betta macrostoma generally eats a protein-rich diet that includes prey fish, shrimp, and some types of worms.

Are Siamese fighting fish aggressive?

Yes, Siamese fighting fish are aggressive.

About the author

I'm Gulshan, a passionate pet enthusiast. Dive into my world where I share tips, stories, and snapshots of my animal adventures. Here, pets are more than just animals; they're heartbeats that enrich our lives. Join our journey!