Home / Fishes / Arowanas and elephantfish / Silver arowana
No federal permit to keepSilver arowana
Osteoglossum bicirrhosum
Fishes › Arowanas and elephantfish (Osteoglossiformes) › Osteoglossidae (Arowanas)
The silver arowana (Osteoglossum bicirrhosum) is a South American freshwater bony fish of the family Osteoglossidae.
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.
Care guide
Species care notes
- Water: a fairly wide range, from slightly acidic to slightly alkaline, 68–86 °F, pH 5–7.5, 2–15 dGH.
- Behaviour: temperament predatory; kept alone; not a community fish.
- Difficulty: Moderate (Seriously Fish rating).
Short excerpts from the species profile:
- Setup: “Relatively unfussy although some surface cover in the form of floating or overhanging vegetation or branches is appreciated.”
- Diet: “This species is a generalised predator with intestinal analyses of wild specimens revealing the natural diet to consist of other fishes, terrestrial insects, aquatic invertebrates and plant material in the form of fallen nuts and fruits.”
- Tankmates: “Peaceful with anything too large to swallow and can be maintained in a community provided tankmates are chosen with care.”
- Breeding: “Unrecorded in aquaria but this species is often bred commercially in outdoor facilities.”
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
Silver arowanas are sometimes kept in aquariums, but they are predatory and require a very large tank. The generic name Osteoglossum means "bone-tongued" and the specific name bicirrhosum means "two barbels" (from the Greek language).
Quoted from the Wikipedia article “Silver 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. Is an omnivore with a tendency to feed on fish at the surface. The superior position of the mouth allows it to capture its prey while swimming from below. Also jumps out of the water to feed on large insects (Coleoptera;. It is capable of adapting to environments with low oxygen levels. |
| 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, 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 90°F (up to 92°F in the hottest sampled areas) |
| Cool-season lows | about 70°F (down to 65°F in the coldest sampled areas) |
| Average temperature | 78–81°F across sampled records |
| Relative humidity | 81–84% on average (driest month about 78%) |
| Rainfall | about 2304 mm a year |
Measured at 177 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 silver arowana (Osteoglossum bicirrhosum) is a South American freshwater bony fish of the family Osteoglossidae. Silver arowanas are sometimes kept in aquariums, but they are predatory and require a very large tank. The generic name Osteoglossum means "bone-tongued" and the specific name bicirrhosum means "two barbels" (from the Greek language). — 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 | Osteoglossum bicirrhosum are not picky eaters. — Animal Diversity Web |
| Behavior | Osteoglossum bicirrhosum have a unique predatory behavior. — Animal Diversity Web |
| Reproduction | The male carries eggs, larvae and early juveniles (alevinos) in his mouth, which lasts for nearly six weeks. — FishBase |
| Appearance and size | Osteoglossum bicirrhosum are characterized by remarkable scale arrangements in which the scales are large, stout, bony and ornamented in a way that the radii form a course pattern. — Animal Diversity Web |
| Biology | Is an omnivore with a tendency to feed on fish at the surface. The superior position of the mouth allows it to capture its prey while swimming from below. Also jumps out of the water to feed on large insects (Coleoptera; ). — FishBase |
| Conservation | The silver arowana is not currently listed on any CITES appendix and is listed as Least Concern on the IUCN Red List. It is one of the most popular ornamental fish from South America, however, and therefore its conservation status merits attention. Other threats include droughts and deforestation, siltation and drainage of land for human use. — 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.
Maximum recorded lifespan
Longest recorded lifespan reported by each database; typical lifespans are usually shorter.
Typical adult weight
Average adult body mass in each database (FishBase gives the maximum recorded weight).
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
- Unilateral ventral strabismus in an aquarium Silver Arowana (Osteoglossum bicirrhosum) Chow DW et al., Veterinary ophthalmology 2016
- Reference genome provide insights into sex determination of silver aworana (Osteoglossum bicirrhosum) Liu Y et al., BMC biology 2025
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
- 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.
- 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.
