Home / Fishes / Arowanas and elephantfish / Asian arowana
Federal restrictions applyAsian arowana
Scleropages formosus
Fishes › Arowanas and elephantfish (Osteoglossiformes) › Osteoglossidae (Arowanas)
The Asian arowana (Scleropages formosus) comprises several phenotypic varieties of freshwater fish distributed geographically across Southeast Asia.
Care at a glance
Species-specific aquarium care
- Tank: At least 180 in long and 72 in front to back for one adult (adults commonly reach about 35.4 in / 90 cm).
- Water: Freshwater.
- Temperature: 75–86°F (range recorded for this species).
- Layout: Uses both the bottom and open water: give open swimming space plus cover near the substrate.
- Diet: A predator: feed meaty foods sized to its mouth (frozen fish, shrimp, worms); it will eat tankmates that fit in its mouth. 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.
Warnings
Care guide
Species care notes
- Water: a fairly wide range, from slightly acidic to slightly alkaline, 72–82 °F, pH 5–8, 2–15 dGH.
- Behaviour: kept alone; not a community fish.
- Difficulty: Moderate (Seriously Fish rating).
Short excerpts from the species profile:
- Setup: “Relatively unfussy and often maintained in completely bare set-ups.”
- Diet: “An obligate predator feeding on smaller fishes, crustaceans and other invertebrates in nature but in most cases adapting well to dead alternatives in captivity.”
- Breeding: “A paternal mouthbrooder that is typically bred in outdoor pools for commercial purposes.”
From the Seriously Fish profile for this species, which has the full habitat, maintenance, diet, behaviour and breeding write-up 167
Arowanas
Applies to most species in this group. Habitat: These surface-oriented freshwater predators inhabit tropical slow-moving tributaries, backwaters, swamps and floodplains, including flooded forest used by South American Osteoglossum. Individual species can differ, so compare with the species numbers above and the linked sources.
Housing & setup
- Plan adult housing before purchase: silver arowanas require public installations or exceptionally large private aquaria.
- The published 180 × 60 × 60 cm minimum for Scleropages jardinii is explicitly an absolute bare minimum; adults can approach 90 cm and need ample unobstructed swimming room.
- Fit a heavy, tightly secured cover because both Osteoglossum and Scleropages are powerful jumpers.
- Use strong filtration, high oxygenation and moderate water movement; never introduce silver arowanas to an immature aquarium.
- Provide some floating or overhanging cover while preserving swimming space; for silver arowanas, perform weekly water changes of 30–50%.
Climate & lighting
| Water | 75.2–84.2°F |
Diet
- Whole prawns or shrimp and mussel flesh.
- Earthworms sized to the fish.
- Gut-loaded insects such as crickets or mealworms.
- Fish flesh for adult silver arowanas.
- Suitable floating pellets as part of a varied diet.
Social life
- Usually house one adult per enclosure. S. jardinii is particularly territorial and some individuals tolerate no tankmates. Silver arowanas may accept carefully selected fishes too large to swallow but can fight conspecifics when space is limited.
Health watch
- Eye and gill problems associated with poor conditions, reported for S. jardinii.
- Parasites or infectious disease introduced with live feeder fish.
- Excess fat deposits and organ degeneration from inappropriate mammal or bird meat diets.
Understanding the animal
About this animal
About this animal
While most consider the different varieties to belong to a single species, work by Pouyaud et al. (2003) differentiates these varieties into multiple species.
Quoted from the Wikipedia article “Asian arowana” (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. Uses both the bottom and open water. Occurs in tannin stained blackwater streams. |
| Water it lives in | Freshwater, 75–86 °F (24–30 °C). |
| Climate | Tropical climate. |
| Wild diet | Hunting macrofauna (predator). |
| Behavior to plan for | Breeding: external brooders. |
What this means for care
- Keep water within its wild range, 75–86 °F.
Native climate (measured)
Native climate (measured)
| Warm-season highs | about 89°F (up to 92°F in the hottest sampled areas) |
| Cool-season lows | about 72°F (down to 64°F in the coldest sampled areas) |
| Average temperature | 76–81°F across sampled records |
| Relative humidity | 78–83% on average (driest month about 77%) |
| Rainfall | about 2377 mm a year, spread fairly evenly |
Measured at 18 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 Asian arowana (Scleropages formosus) comprises several phenotypic varieties of freshwater fish distributed geographically across Southeast Asia. While most consider the different varieties to belong to a single species, work by Pouyaud et al. (2003) differentiates these varieties into multiple species. They have several other common names, including Asian bonytongue, dragonfish, and a number of names specific to the different color varieties. Native to Southeast Asia, Asian arowanas inhabit blackwater rivers, slow-moving waters flowing through forested swamps and wetlands. — 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 |
| Behavior | They spend the day in the protection of Pandanus roots or other structures, and feed at night. It is normally seen alone or in small groups. — Wikipedia (community-edited) |
| Reproduction | From an observation of a breeding pair in a concrete tank, courtship lasts from several weeks to months. During this stage, the breeding pair swims near the water surface usually at night. "The male chases the female around the perimeter of the tank. Sometimes, the pair circle each other nose-to-tail. — FishBase |
| Appearance and size | Maximum length 90.0 cm tl male/unsexed. — FishBase |
| Biology | Occurs in tannin stained blackwater streams. Found in forest covered streams including peat adjacent areas. Take around three months for free swimming fries. — FishBase |
| History and naming | Like all members of the Osteoglossidae, Asian arowanas are highly adapted to fresh water and are incapable of surviving in the ocean. Therefore, their spread throughout the islands of Southeast Asia suggests they diverged from other osteoglossids before the continental breakup of Pangaea was complete. — Wikipedia (community-edited) |
| Conservation | Asian arowanas are listed as endangered by the current IUCN Red List, with the most recent evaluation taking place in 2019. International trade in these fishes is controlled under the Convention on the International Trade in Endangered Species of Wild Flora and Fauna (CITES), under which it was placed on Appendix I, the most restrictive category, in 1975. — Wikipedia (community-edited) |
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 total length. Fish in home aquariums often stay smaller than wild records.
Water temperature
Range the species tolerates in nature; aim for the middle.
pH
Water hardness
Veterinary & husbandry research
Veterinary & husbandry research
- Sustainable aquaculture of Asian arowana--a review Medipally SR et al., Journal of environmental biology 2016
- Identification of candidate sex-specific genomic regions in male and female Asian arowana genomes Mu X et al., GigaScience 2022
- Development and validation of a species-specific environmental DNA (eDNA) primer for endangered Asian arowana, Scleropages formosus (Teleostei: Osteoglossidae) for law enforcement and wild population monitoring Mohd-Azhar NAE et al., MethodsX 2025
- Gonadal transcriptome sequencing reveals sexual dimorphism in expression profiling of sex-related genes in Asian arowana (Scleropages formosus) Zhao C et al., Frontiers in genetics 2024
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. 170
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.
- 50 CFR 17.11: Endangered and threatened wildlife Zoo, university or veterinaryCurrent federal Endangered Species Act list.
- Species+ (UNEP-WCMC and the CITES Secretariat) Zoo, university or veterinaryThe official database of species listed under CITES.
- USFWS International Affairs: CITES Zoo, university or veterinaryFederal agency that issues CITES permits.
- Seriously Fish: Osteoglossum bicirrhosum Experienced keeper or breederAdded in the 2026 source-checked care-guide review.
- Seriously Fish: Scleropages jardinii Experienced keeper or breederAdded in the 2026 source-checked care-guide review.
- U.S. Fish and Wildlife Service: Asian Bonytongue ecological risk screening summary Experienced keeper or breederAdded 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.
- 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.
