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Simor Betta

Betta simorum

Also known as Simor Fighter

Fishes › Gouramis, bettas, snakeheads (Anabantiformes) › Osphronemidae (Gouramis and bettas)

Betta simorum is a species of gourami endemic to Indonesia.

Aquarium hobby
Experience: Beginner
Simor Betta
Photo: R.J. Blach, CC BY-SA 3.0, via Wikimedia Commons
FamilyGouramis and bettas
Adult lengthup to 3.5 in
WaterFreshwater

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 2.5 in / 6.38 cm).
  • Water: Freshwater.
  • 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, 77–86 °F, pH 3–6, 1–5 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: “A study conducted in 1994 (in which the species was considered to be B.”
  • 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

Group care guide

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.

Sources 117119164118252253

Diet

  • Betta pellets plus frozen foods.

Sources 117119164118252253

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.

Sources 117119164118252253

Health watch

  • Fin rot in dirty water; never keep bettas in tiny unheated bowls.

Sources 117119164118252253

Understanding the animal

About this animal

About this animal

This species grows to a length of 6.4 centimetres (2.5 in) SL. This species can also be found in the aquarium trade. The species was named simorum and uses the Latin genitive plural "of the Sims", named so in honour of Thomas G. K. Sim and his wife Farrah, of Sindo Aquarium in Jambi, Sumatra.

Quoted from the Wikipedia article “Betta simorum” (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 livesLives in freshwater. Uses both the bottom and open water.
Water it lives inFreshwater.
ClimateTropical climate.
  1. FishBase species summary: Betta simorum
Native climate (measured)

Native climate (measured)

Warm-season highsabout 89°F (up to 89°F in the hottest sampled areas)
Cool-season lowsabout 73°F (down to 72°F in the coldest sampled areas)
Average temperature80–81°F across sampled records
Relative humidity82–82% on average (driest month about 80%)
Rainfallabout 2530 mm a year, spread fairly evenly

Measured at 5 wild occurrence records sampled against WorldClim 2.1 climate data (1970–2000 averages). Air conditions in the range are ecological context, not enclosure settings: microhabitats such as burrows, leaf litter or basking rocks can be cooler, warmer or more humid.

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.

OverviewBetta simorum is a species of gourami endemic to Indonesia. This species grows to a length of 6.4 cm SL. This species can also be found in the aquarium trade. The species was named simorum and uses the Latin genitive plural "of the Sims", named so in honour of Thomas G. K. Sim and his wife Farrah, of Sindo Aquarium in Jambi, Sumatra. — Wikipedia (community-edited)
Where it livesHome 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

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

Average of sources3in
FishBase 1642.5
Seriously Fish species profiles 1673.5

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

Reported77–86°F
Seriously Fish species profiles 16777–86

Range the species tolerates; aim for the middle.

pH

Reported3–6
Seriously Fish species profiles 1673–6

Water hardness

Reported1–5dGH
Seriously Fish species profiles 1671–5

Minimum tank footprint

Reported31in
Seriously Fish species profiles 16731

Seriously Fish recommends a tank base of at least 31 × 12 in (about 19 US gallons).

Sources for this sheet

  1. 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.
  2. 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.
  3. Merck Veterinary Manual: Management of aquarium fish Zoo, university or veterinaryThe Merck Veterinary Manual: a standard veterinary reference written and reviewed by veterinary specialists.
  4. 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.
  5. Merck Veterinary Manual: Nutritional diseases of fish Zoo, university or veterinaryThe Merck Veterinary Manual: a standard veterinary reference written and reviewed by veterinary specialists.
  6. Seriously Fish — Betta splendens Zoo, university or veterinaryAdded in the 2026 source-checked care-guide review.
  7. Seriously Fish — Betta imbellis Zoo, university or veterinaryAdded in the 2026 source-checked care-guide review.
  8. Wikipedia (species article) Community referenceFree encyclopedia; useful overviews with their own citations. Intro text is quoted under CC BY-SA 4.0.
  9. iNaturalist (captive observations) Community referenceCommunity observation platform run by the California Academy of Sciences and National Geographic; observations marked captive show animals living in homes, zoos and aquariums.