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No federal permit to keepSiamese fighting fish
Betta splendens
Fishes › Gouramis, bettas, snakeheads (Anabantiformes) › Osphronemidae (Gouramis and bettas)
The Siamese fighting fish (Betta splendens), commonly known as the Siamese fighter, or locally as the betta, is a freshwater fish native to Mainland Southeast Asia, namely Cambodia, Laos, Myanmar, Malaysia, Thailand, and Vietnam.
Care at a glance
Species-specific values
Values researched for this exact species. Where they differ from the group guide below, follow these. Air, surface and water temperatures are listed separately, and each source is kept as published rather than averaged.
| Water temperature | 72–86 °F (22–30 °C) Maintenance recommendations from this source; do not replace with a multisource average. | 252 |
| Water pH | 6–8 Maintenance recommendations from this source; do not replace with a multisource average. | 252 |
| Water general hardness | 1–15 dGH Maintenance recommendations from this source; do not replace with a multisource average. | 252 |
| Adult standard length | 70 mm Maximum standard length reported by source; excludes caudal fin, not total body length. | 252 |
| Minimum tank base | length: 45 cm; width: 30 cm Minimum aquarium base recommended by this source, not a tank-volume specification. | 252 |
| Social | Best maintained alone according to the detailed compatibility section. The page quick-facts label says “in a pair”, which conflicts with its detailed prose. Follow the detailed care discussion; this source inconsistency is retained explicitly. | 252 |
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 / 6.5 cm).
- Water: Freshwater.
- Temperature: 75–86°F (range recorded for this species).
- pH: 6–8.
- Hardness: 5–19 dGH.
- Layout: Uses both the bottom and open water: give open swimming space plus cover near the substrate.
- Diet: FishBase classes it as a carnivore.
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 18 × 12 in (roughly 11 US gallons); space needed is rated “modest tank”.
- Water: a fairly wide range, from slightly acidic to slightly alkaline, 72–86 °F, pH 6–8, 1–15 dGH.
- Behaviour: temperament species tank; in a pair; not a community fish.
- Difficulty: Moderate (Seriously Fish rating).
Short excerpts from the species profile:
- Setup: “This species fares best in a well-planted, shady aquarium with plenty of surface cover in the form of tall stem plants, floating types such as Salvinia or Riccia spp., or tropical lilies from the genus Nymphaea.”
- Diet: “Likely to prey on aquatic and terrestrial invertebrates in nature.”
- Tankmates: “Not recommended for the standard community aquarium.”
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 is one of more than 70 species of the genus Betta, but the only one eponymously called "betta", owing to its global popularity as a pet; Betta splendens are among the most popular aquarium fish in the world, due to their diverse and colorful morphology and relatively low maintenance. Betta fish are endemic to the central plain of Thailand, where they were first domesticated more than 1,000 years ago, among the earliest of any fish.
Quoted from the Wikipedia article “Siamese fighting fish” (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, in rivers and streams, mangroves. Uses both the bottom and open water. Occur in standing waters of floodplains, canals, rice paddies. |
| Water it lives in | Freshwater, 75–86 °F (24–30 °C), pH 6–8, hardness 5–19 dH. |
| Climate | Tropical climate. |
| Behavior to plan for | Breeding: nesters, paternal parental care. |
What this means for care
- Keep water within its wild range, 75–86 °F.
- Parents guard eggs or young, so expect territorial behavior when breeding.
Native climate (measured)
Native climate (measured)
| Warm-season highs | about 93°F (up to 97°F in the hottest sampled areas) |
| Cool-season lows | about 69°F (down to 65°F in the coldest sampled areas) |
| Average temperature | 78–83°F across sampled records |
| Relative humidity | 71–79% on average (driest month about 67%) |
| Rainfall | about 1356 mm a year, with strong wet and dry seasons |
Measured at 33 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.
| Overview | The Siamese fighting fish (Betta splendens), commonly known as the Siamese fighter, or locally as the betta, is a freshwater fish native to Mainland Southeast Asia, namely Cambodia, Laos, Myanmar, Malaysia, Thailand, and Vietnam. It is one of more than 70 species of the genus Betta, but the only one eponymously called "betta", owing to its global popularity as a pet; Betta splendens are among the most popular aquarium fish in the world, due to their diverse and colorful morphology and relatively low maintenance. — 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 |
| Wild diet | Wild Betta splendens feed mainly on insects that have fallen into the water. — Animal Diversity Web |
| Behavior | During the dry season, most Bettas are able to bury themselves in the bottom of their dried up habitat. — Animal Diversity Web |
| Reproduction | Builds bubble-nest which is guarded by male. — FishBase |
| Appearance and size | The Betta, on average, is 7.5 centimeters in length. — Animal Diversity Web |
| Biology | Facultative air-breathing; Occur in standing waters of floodplains, canals, rice paddies and medium to large rivers. Feed on zooplankton, mosquito and other insect larvae. Air breather and bubble nest builder. — FishBase |
| History and naming | Outside Southeast Asia, the name "betta" is used specifically to describe B. splendens, despite the term scientifically applying to the entire genus, which includes B. splendens and dozens of other species. Betta splendens is more accurately called by its scientific name or "Siamese fighting fish" to avoid confusion with the other members of the genus. — Wikipedia (community-edited) |
| Conservation | The Betta is not endangered. — Animal Diversity Web |
Data and studies
Researched care notes
Researched care notes
Findings checked against veterinary, zoo, welfare, keeper and peer-reviewed sources. Air, basking-surface and water temperatures are kept separate, and where sources disagree both are shown. “Study” notes report what a paper measured, not a universal rule.
Siamese Fighting Fish / Domestic Betta (species)
- OATA recommends at least 20 L for one male, with filtration, cover, gentle current, and air-surface access. Preserve usable water volume and furnishings as separate considerations.1
- The 2024 fishbowl experiment found less swimming in 0.5 L than in the tested larger aquaria. Study finding in males.2
- The second 2024 study favoured a furnished 19.3-L setup over smaller or barren setups on measured behaviours. Study finding in males.3
- Do not routinely cohouse males. Even large tested aquaria did not guarantee peaceful coexistence.1
- OATA publishes a broad 20–28°C water range and calls for a heater. This does not prove that every point is equally suitable for routine maintenance. Confidence: LOW.1
The numbers
The numbers
Each bar is what one source reports. Where several sources weigh in, the dashed gold band marks their average.
Maximum recorded lifespan
Longest recorded lifespan reported by each database; typical lifespans are usually shorter.
Adult length
Maximum recorded length. Measured as total length. Fish in home aquariums often stay smaller than wild records.
Water temperature
Range the species tolerates in nature; aim for the middle.
Minimum tank footprint
Seriously Fish recommends a tank base of at least 18 × 12 in (about 11 US gallons).
Veterinary & husbandry research
Veterinary & husbandry research
- Complete mitochondrial genome of the Siamese fighting fish (Betta splendens) Song YN et al., Mitochondrial DNA. Part A, DNA mapping, sequencing, and analysis 2016
- Life in a bubble: the role of the labyrinth organ in determining territory, mating and aggressive behaviours in anabantoids Tate M et al., Journal of fish biology 2017
- Genomic consequences of domestication of the Siamese fighting fish Kwon YM et al., Science advances 2022
- A survey of coccidian infections of freshwater fishes of Peninsular Malaysia, with descriptions of three species of Goussia Labbé, 1896 (Apicomplexa: Eimeriidae) Molnár K et al., Systematic parasitology 2003
Peer-reviewed papers that mention this species alongside captivity, zoos, veterinary care or aquaculture. Some cover several species or mention it only in passing, so check the abstract. See all 30 on PubMed → 170
Sources for this sheet
- AnAge: The Animal Ageing and Longevity Database (Human Ageing Genomic Resources) Peer-reviewed researchCurated, referenced longevity and life-history records for thousands of species; maximum lifespans are often from zoo animals.
- 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.
- Clint's Reptiles (YouTube): Betta, The Best Pet Fish? Expert educator & keeperClint Laidlaw, PhD in Biology Education and MS in Evolutionary Ecology; owner of Clint's Reptile Room and a longtime keeper. His "Best Pet?" series reviews each species' care in depth.
- Wikipedia (species article) Community referenceFree encyclopedia; useful overviews with their own citations. Intro text is quoted under CC BY-SA 4.0.
- PubMed (U.S. National Library of Medicine) Peer-reviewed researchIndex of peer-reviewed veterinary, zoo and husbandry research.
- 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.
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