Home / Fishes / Gouramis, bettas, snakeheads / Spotfin betta
No federal permit to keepSpotfin betta
Betta macrostoma
Fishes › Gouramis, bettas, snakeheads (Anabantiformes) › Osphronemidae (Gouramis and bettas)
The spotfin betta or Brunei beauty (Betta macrostoma) is a species of labyrinth fish endemic to the island of Borneo.
Care at a glance
Species-specific aquarium care
- Tank: At least 24 in long and 12 in front to back for one adult (adults commonly reach about 2.6 in / 6.7 cm).
- Water: Freshwater.
- Temperature: 75–79°F (range recorded for this species).
- pH: 4.4–5.7.
- Hardness: 0–10 dGH.
- Layout: Uses both the bottom and open water: give open swimming space plus cover near the substrate.
Calculated from this species' own FishBase record: tank size from its typical adult length and swimming zone, water values from its recorded ranges. The group guide below fills in general care.
Care guide
Species care notes
- Tank: a base of at least 31 × 12 in (roughly 19 US gallons); space needed is rated “modest tank”.
- Water: soft, acidic water, 68–77 °F, pH 4–6, 0–5 dGH.
- Behaviour: temperament species tank; in a pair; not a community fish.
- Difficulty: Moderate (Seriously Fish rating).
Short excerpts from the species profile:
- Setup: “Can be maintained in a fully-decorated aquarium although many breeders prefer not to use a substrate for ease of maintenance.”
- Diet: “Likely to prey on insects and other small invertebrates/zooplankton in nature, plus perhaps the shrimp that share its habitat.”
- Tankmates: “Not recommended for the standard community set-up for reasons already touched upon.”
From the Seriously Fish profile for this species, which has the full habitat, maintenance, diet, behaviour and breeding write-up 167
Bettas (fighting fish)
Applies to most species in this group. Habitat: Shallow rice paddies and marshes. Individual species can differ, so compare with the species numbers above and the linked sources.
Housing & setup
- A heated, filtered tank of at least 5 gallons, with gentle flow and plants.
- Domestic B. splendens should generally be maintained alone. Other Betta species need their own compatibility plan; B. imbellis can be maintained as a pair with adequate cover.
Diet
- Betta pellets plus frozen foods.
Social life
- Use species-specific social housing: B. splendens alone under the detailed Seriously Fish recommendation; B. imbellis may be housed as a compatible pair.
Health watch
- Fin rot in dirty water; never keep bettas in tiny unheated bowls.
Understanding the animal
About this animal
About this animal
It generally inhabits pools of very slow-moving water along rivers and streams in very shallow waters of 30 cm (12 in) or less. This species grows to a length of 6.7–10 cm (2.6–3.9 in) in the wild, and is occasionally found in the aquarium trade; in captivity this species regularly reaches 10.1 cm (4 in) in length.
Quoted from the Wikipedia article “Spotfin betta” (CC BY-SA 4.0) 174
In the wild
In the wild
From this species’ own FishBase record (habitat, bottom type, water and breeding data), not its family. Good care copies these conditions.1
| Where it lives | Lives in freshwater. Uses both the bottom and open water. Inhabits shallow (about 30 cm deep) near stagnant pools along stream bed with substrate consisting of clay. |
| Water it lives in | Freshwater, 75–79 °F (24–26 °C), pH 4.4–5.7, hardness 10 dH. |
| Climate | Tropical climate. |
| Behavior to plan for | Breeding: external brooders. |
What this means for care
- Keep water within its wild range, 75–79 °F.
From the sources
From the sources
Quoted from the matching sections of reputable sources for this exact species. Specialist databases are used first; Wikipedia (community-edited, CC BY-SA 4.0) only fills gaps. Other sources are short credited quotes.
| Overview | The spotfin betta or Brunei beauty (Betta macrostoma) is a species of labyrinth fish endemic to the island of Borneo. It generally inhabits pools of very slow-moving water along rivers and streams in very shallow waters of 30 cm or less. This species grows to a length of 6.7-10 in the wild, and is occasionally found in the aquarium trade; in captivity this species regularly reaches 10.1 cm (4 in) in length. It also has a rectangular body. — Wikipedia (community-edited) |
| Where it lives | Home ranges Population dynamics Growth parameters Max. ages / sizes Length-weight rel. Length-frequencies Mass conversion Recruitment Abundance Life cycle Reproduction Maturity Maturity/Gills rel. — FishBase |
| Reproduction | Male carries the eggs in the mouth. — FishBase |
| Biology | Facultative air-breathing; Inhabits shallow (about 30 cm deep) near stagnant pools along stream bed with substrate consisting of clay. Occurs also in waterfalls with fast flowing clear water; occupies small pools in tributaries and quiet pools along the main confluence of the river. — FishBase |
Data and studies
The numbers
The numbers
Each bar is what one source reports. Where several sources weigh in, the dashed gold band marks their average.
Adult length
Maximum recorded length. Measured as standard length (snout to the base of the tail, not counting the tail fin). Fish in home aquariums often stay smaller than wild records.
Water temperature
Range the species tolerates in nature; aim for the middle.
Water hardness
Minimum tank footprint
Seriously Fish recommends a tank base of at least 31 × 12 in (about 19 US gallons).
Sources for this sheet
- FishBase (Froese & Pauly, eds.), version 24.07 Peer-reviewed researchThe global scientific database on fishes, maintained by a consortium of research institutions; every value is referenced.
- Seriously Fish species profiles Experienced keeper or breederLong-running aquarium reference written and peer-checked by experienced fishkeepers and ichthyologists; each profile covers habitat, tank size, water, diet, behaviour and breeding.
- Merck Veterinary Manual: Management of aquarium fish Zoo, university or veterinaryThe Merck Veterinary Manual: a standard veterinary reference written and reviewed by veterinary specialists.
- Merck Veterinary Manual: Types and features of aquatic systems Zoo, university or veterinaryThe Merck Veterinary Manual: a standard veterinary reference written and reviewed by veterinary specialists.
- Merck Veterinary Manual: Nutritional diseases of fish Zoo, university or veterinaryThe Merck Veterinary Manual: a standard veterinary reference written and reviewed by veterinary specialists.
- Seriously Fish — Betta splendens Zoo, university or veterinaryAdded in the 2026 source-checked care-guide review.
- Seriously Fish — Betta imbellis Zoo, university or veterinaryAdded in the 2026 source-checked care-guide review.
- Wikipedia (species article) Community referenceFree encyclopedia; useful overviews with their own citations. Intro text is quoted under CC BY-SA 4.0.
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