
AI-generated image
Betta macrostoma
A rare wild betta found only in Brunei and the northern tip of Sarawak. Males are orange-red with black-edged fins and an ocellus. A paternal mouthbrooder that needs cool, strongly acidic, very soft water.
Betta macrostoma, the Brunei beauty, is endemic to Brunei Darussalam and the northern tip of Sarawak in Borneo. FishBase gives 6.7cm SL and Seriously Fish 100mm SL. Males are orange-red with black-edged fins and an ocellus, and flare the gill covers widely when displaying. It lives in shallow, near-stagnant pools over clay stream beds and in fast water near waterfalls. It needs cool water of 20-25C with pH 4.0-6.0 and 0-5 dGH - strongly acidic and very soft. A pair fits a tank of about 80 x 30cm, roughly 72 litres. It is a paternal mouthbrooder: the male wraps his body around the female at spawning, then incubates the eggs for 14-35 days before releasing free-swimming fry of 5mm or more. Its very restricted range places it as Vulnerable on the IUCN Red List.
Source: Wikipedia (CC BY-SA 4.0)
The Brunei Beauty lives 2-4 years.
The Brunei Beauty grows to About 7-10cm.
The ideal temperature for the Brunei Beauty is 20〜25℃.
Origin
Borneo (Brunei Darussalam and the northern tip of Sarawak, Malaysia)
Lifespan
2-4 years
Size
Sources: Seriously Fish / FishBase
Edited & verified by: BreederDirect editorial team
The taxonomic, regulatory, and husbandry data on this page are compiled and verified against the authoritative primary sources below.
Accepted name: Betta macrostoma Regan, 1910
Authority databases: FishBase
Nomenclature follows global taxonomic authority databases.
Sources: CITES Appendices (species not listed) / IUCN Red List
Regulations may change. Always verify the latest information with the relevant authorities.
Find listings for this species
About 7-10cm
Temperature
20〜25℃
Frozen and live foods (Daphnia, Artemia, bloodworm), dried foods
From about 80 x 30cm (72 litres) for a pair. Provide shaded cover with wood and leaf litter, and close the lid completely against jumping.
Keep it cool at 20-25C with pH 4.0-6.0 and 0-5 dGH - strongly acidic and very soft. Warm water quickly puts the fish out of condition.
Not a community fish; keep as a pair. A group is sometimes maintained temporarily so fish can choose partners, but males fight hard.
It eats insects and small invertebrates in the wild. Offer Daphnia, Artemia or bloodworm regularly alongside dried foods.
A paternal mouthbrooder. The male wraps around the female at spawning and incubates for 14-35 days, releasing fry of 5mm or larger.
Listed as Vulnerable by the IUCN. Its range is tiny and supply is limited, so check the provenance of any fish, and secure a location that stays cool.
Advanced. This is an advanced-level species. It requires specialized equipment and advanced husbandry skills with precise environmental control.
The ideal temperature for Brunei Beauty is 20〜25℃. Avoid sudden temperature changes and maintain a stable environment.
The average lifespan of Brunei Beauty is 2-4 years. With proper care and nutrition, they can live a long and healthy life.
Brunei Beauty typically reaches About 7-10cm as an adult. Size may vary depending on care conditions and individual genetics.
Brunei Beauty feeds on: Frozen and live foods (Daphnia, Artemia, bloodworm), dried foods. Aim for a balanced diet with appropriate feeding frequency.
The price of Brunei Beauty varies significantly depending on morph, size, and lineage. Check our market price page for the latest pricing information.
Last updated: September 17, 2026