Angelfish
A tall, laterally compressed cichlid whose height — 20 cm or more from fin tip to fin tip — matters more than its length. It is a cichlid, not a community fish: adults pair off, claim territory and will kill smaller tankmates.
Quick profile
- Scientific name
- Pterophyllum scalare
- Adult size
- 12–15 cm (4.7–5.9 in)
- Lifespan
- 8–12 years
- Temperature
- 24–29 °C (75–84 °F)
- pH
- 6–7.5
- Hardness
- 2–15 °dGH
- Minimum tank
- 200 L (53 US gal)
- Minimum length
- 100 cm
- Swimming zone
- Midwater
- Social
- Pair — at least 1
- Diet
- Carnivore
- Overall confidence
- high confidence
What keeping this species involves
Undemanding chemically, but the tank height, the adult aggression and the pairing dynamic are all routinely underestimated.
Slow, structured water among submerged branches and marginal vegetation.
Identity and names
- Common name
- Angelfish
- Scientific name
- Pterophyllum scalare
- Family
- Cichlidae
- Order
- Cichliformes
- Class
- Actinopterygii
- Also sold as
- freshwater angelfish, scalare
Varieties and strains
| Variety | What it means in practice |
|---|---|
| Veil and super-veil | Extended fins increase the height requirement further and swim poorly. |
| Koi, marble, platinum, zebra | Colour strains of the same species; behaviour unchanged. |
Adult size and growth
12–15 cm (4.7–5.9 in) — Body length 12–15 cm; total height including the fins commonly exceeds 20 cm.
Typical lifespan in an aquarium: 8–12 years. Almost every animal sold in a shop is a juvenile, so the tank has to suit the size in the first line rather than the size in the bag.
Shape, which is what the compatibility engine reads instead of length alone: disc — as deep as it is long with a moderate. A mature Pterophyllum scalare is as deep as it is long and laterally compressed to a blade. Judged on length alone it looks like a mouthful for anything half again its size; judged on cross-section it is one of the hardest community fish to swallow.
Water and tank requirements
Height is the binding constraint: a tank under about 45 cm deep cannot accommodate adult fin extension. A metre of length gives a pair room to hold territory without cornering everything else.
Temperature (°C)
Scale: 0 to 36 °C.
pH (pH)
Scale: 4 to 9.5 pH.
Hardness (°dGH)
Scale: 0 to 30 °dGH.
Where these figures come from
Habitat class
Lowland floodplain
Seasonally inundated flat country — várzea, chaco, swamp margin — where the water body changes size, depth and chemistry through the year.
The habitat's defining feature is change, so a single band describes it badly. Species from here are generally tolerant of a wide range and intolerant of nothing much — which makes them easy to keep and easy to keep wrongly.
- Conductivity
- 40–300 µS/cm
- Flow
- still
- Dissolved oxygen
- low
- Seasonality
- strong
These are figures for the KIND of water body, not measurements of this species. They are AquariumHQ’s summary of the general limnology and are given wide because the water is.
- TemperatureA source publishes a value
- A registered source publishes a temperature figure for this species. See the evidence panel for what kind of figure it is.
- pHFollows the habitat this animal comes from
- Follows the water this animal is recorded from — lowland floodplain. Lowland floodplain generally runs 6–7.5, and the advised band of 6–7.5 is consistent with it. This is AquariumHQ's reasoning from the habitat, not a measurement of the species. A source does publish a figure for this parameter, and it answers a different question — an environmental range or a laboratory tolerance rather than a keeping recommendation. It is held alongside this band rather than behind it.
- General hardnessFollows the habitat this animal comes from
- Follows the water this animal is recorded from — lowland floodplain. Lowland floodplain generally runs 2–12 dGH, and the advised band of 2–15 dGH is consistent with it. This is AquariumHQ's reasoning from the habitat, not a measurement of the species. A source does publish a figure for this parameter, and it answers a different question — an environmental range or a laboratory tolerance rather than a keeping recommendation. It is held alongside this band rather than behind it.
Scale: 5.8 to 7.7 pH.
Scale: 0.1 to 17 dGH.
| Requirement | Value | Notes |
|---|---|---|
| Temperature | 24–29 °C (75–84 °F) | Stability matters more than hitting an exact figure. |
| pH | 6–7.5 | A stable pH outside the ideal band is usually better than an unstable one inside it. |
| General hardness | 2–15 °dGH | Check your supplier's published figure before choosing species. |
| Minimum volume | 200 L (53 US gal) | A floor, not a recommendation. |
| Minimum footprint | 100 cm long | Height is the binding constraint: a tank under about 45 cm deep cannot accommodate adult fin extension. A metre of length gives a pair room to hold territory without cornering everything else. |
| Water flow | low | Match the outflow to this rather than to the filter's rating. |
| Lid required | Recommended | Reduces evaporation and prevents accidents. |
| Structure | Tall planting and vertical wood; angelfish orient to vertical structure. |
Behaviour
- Eats neon tetras and other small fish once grown — a classic and entirely predictable failure.
- Long ventral filaments are a standing target for fin-nippers.
Telling males from females
Very little externally; sexing is usually only reliable from the breeding tubes during spawning.
Feeding
- Diet type
- Carnivore
- Staples
- Dry foods, Frozen bloodworm and brine shrimp, Live foods
Breeding
- Strategy
- Substrate spawner on a vertical surface; both parents guard
- Difficulty
- straightforward
- Parental care
- guarding
Pairs spawn readily. First-time parents commonly eat the first several clutches.
Tankmates and compatibility
Assessments are derived from stored traits by the compatibility engine, with the reasoning shown. A verdict is a statement about probability, not a guarantee — individual temperament can override it.
| Towards | Risk | What it means |
|---|---|---|
| Small fish | high | Anything that fits in the mouth is at risk once this species reaches adult size. |
| Adult dwarf shrimp | near-certain | Cover reduces losses but rarely prevents them where the risk is high. |
| Shrimplets | near-certain | Determines whether a shrimp colony can grow rather than merely persist. |
| Snails | low | Applies to snails you wanted as well as snails you did not. |
| Long or trailing fins | occasional | Fin damage is an entry point for secondary infection. |
| Plants | none | Tough species such as Anubias and Java fern survive most grazers. |
Assessed pairings
Any pair in the catalogue can be assessed with the compatibility checker.
Welfare considerations
Points where the way this species is commonly sold or kept differs from what it actually needs.
- Sold at 3 cm the size of a coin, and reaching 15 cm tall in a year.
- A breeding pair will attempt to clear the entire tank of other fish.
Problems to watch for
Most problems in a tank containing this species are general rather than species-specific. Start with the troubleshooting index and work from the observation rather than from a guess at the cause.
What AquariumHQ does not yet hold
Species-level disease susceptibility is modelled in the graph and is not yet populated. Health pages will not be published until each condition has veterinary sourcing, because health content written without evidence is the most harmful thing this product could publish. The gap is recorded in the coverage report.
Where it comes from
- Native range
- Amazon basin — Peru, Colombia, Brazil, Guyana
- Habitat
- Slow, structured water among submerged branches and marginal vegetation.
What the checklists say
22 distribution statements retrieved from GBIF checklists. Establishment means is reproduced from the source where it states one, and left unstated where it does not — a record of presence is not a record of origin.
| Status | Places | What this means |
|---|---|---|
| Native | 6 | A checklist states the species occurs here naturally. |
| Introduced | 10 | A checklist states the species arrived here with human help. That is not a statement that it is established, harmful or illegal. |
| Recorded as present, establishment means not stated | 6 | The source records the species as present and does not say whether it is native or introduced. AquariumHQ does not fill that in. |
Evidence
Every stored value with the kind of support behind it and where to check it. Evidence type and confidence are separate axes: an editorial position held confidently and a measurement held tentatively are different things.
| Claim | Value | Evidence type | Confidence | Source |
|---|---|---|---|---|
| scientific name | Pterophyllum scalare | Observed / measured | high confidence | Catalogue of Life; GBIF — Global Biodiversity Information Facility |
| native range | Amazon basin — Peru, Colombia, Brazil, Guyana | Observed / measured | moderate confidence | GBIF — Global Biodiversity Information Facility |
| adult size | 12–15 cm | Aquarium-literature consensus | high confidence | AquariumHQ husbandry synthesis |
| lifespan | 8–12 years | Aquarium-literature consensus | high confidence | AquariumHQ husbandry synthesis |
| temperature | 24–29 °C | Aquarium-literature consensus | high confidence | AquariumHQ husbandry synthesis |
| ph | 6–7.5 pH | Aquarium-literature consensus | high confidence | AquariumHQ husbandry synthesis |
| general hardness | 2–15 °dGH | Aquarium-literature consensus | high confidence | AquariumHQ husbandry synthesis |
| minimum tank volume | ≥ 200 L | AquariumHQ editorial position | moderate confidence | AquariumHQ husbandry synthesis |
| minimum tank length | ≥ 100 cm | AquariumHQ editorial position | moderate confidence | AquariumHQ husbandry synthesis |
| minimum group size | ≥ 1 | AquariumHQ editorial position | high confidence | AquariumHQ husbandry synthesis |
Last reviewed 2026-08-10. Values labelled as an aquarium-literature consensus are AquariumHQ editorial positions rather than measurements — see how evidence is handled.
Why we say this
What each figure on this page rests on, and how far that is from being independently established.
Every figure on this page has a provenance. Open any claim to see what AquariumHQ holds for it, which sources say what, and what a claim of that kind actually needs. Different claims need different evidence: an accepted scientific name is settled by one authority, while a legal restriction needs a current primary instrument. A single source is often the right answer rather than a thin one.
scientific nameAquariumHQ's own position, externally checkableBased on a verified authoritative source.
AquariumHQ's own position on a claim an external source could support.
What this kind of claim needs: accepted scientific name and classification — 1 authoritative source in an appropriate context. Checked against gbif on 2026-08-11. One authoritative backbone is what this class requires.
What would improve this: Go and read a source. This is reachable and has not been reached.
native rangeAquariumHQ's own position, externally checkableBased on a verified authoritative source.
AquariumHQ's own position on a claim an external source could support.
What this kind of claim needs: where the species occurs — 1 authoritative source in an appropriate context. 22 distribution statements held from GBIF checklists — native in 6, introduced in 10 countries. Establishment means is reproduced from the source, never inferred from occurrence.
What would improve this: Go and read a source. This is reachable and has not been reached.
adult sizeSources disagreeConfirmed by more than one independent source.2 citations, 2 independent origins
Sources give values that do not reconcile. Recorded rather than averaged.
- 10.5 cm — FishBase · Maximum recorded · The range the species is recorded from · checked 2026-08-11
- 15 cm — USGS Nonindigenous Aquatic Species database · Maximum recorded · Observed in the wild · checked 2026-08-29
What this kind of claim needs: size a well-kept specimen reaches — no external source is required, provided AquariumHQ shows its reasoning. 2 independent origins.
What would improve this: Editorial resolution. More reading will not settle this on its own.
lifespanAquariumHQ's own position, externally checkableAquariumHQ's own position, derived from evidenced inputs.
AquariumHQ's own position on a claim an external source could support.
What this kind of claim needs: what aquariumhq advises for keeping — no external source is required, provided AquariumHQ shows its reasoning. No external source is required for this class. AquariumHQ's position stands on its stated reasoning.
What would improve this: Go and read a source. This is reachable and has not been reached.
temperatureIndependently verifiedConfirmed by more than one independent source.2 citations, 2 independent origins
2 citations from 2 independent origins.
- 22–27 °C — Ornamental Aquatic Trade Association · Recommended for keeping · Recommended for keeping · checked 2026-08-11
- 24–30 °C — FishBase · Tolerated range · The range the species is recorded from · checked 2026-08-11
What this kind of claim needs: what aquariumhq advises for keeping — no external source is required, provided AquariumHQ shows its reasoning. 2 independent origins.
What would improve this: Nothing. Recheck when the sources are next reviewed.
phOne sourceAquariumHQ's own position, derived from evidenced inputs.1 citation, 1 independent origin
A single source: fishbase.
- 6–8 pH — FishBase · Tolerated range · The range the species is recorded from · checked 2026-08-11
What this kind of claim needs: what aquariumhq advises for keeping — no external source is required, provided AquariumHQ shows its reasoning. Derived from the observed range rather than copied from it. No usable species-specific observation is held for this parameter. The only figure the source publishes is one it repeats across unrelated families, which the lineage detector grades a default rather than a measurement of this fish. The advised band is therefore AquariumHQ's own position from general husbandry practice for this kind of animal, and is presented as that rather than as a sourced range.
What would improve this: Corroborate against a second, independent source.
general hardnessOne sourceAquariumHQ's own position, derived from evidenced inputs.1 citation, 1 independent origin
A single source: fishbase.
- 5–13 °dGH — FishBase · Tolerated range · The range the species is recorded from · checked 2026-08-11
What this kind of claim needs: what aquariumhq advises for keeping — no external source is required, provided AquariumHQ shows its reasoning. Derived from the observed range rather than copied from it. The advised band reaches past the observed envelope and carries no individual review. Commercially bred stock is generally more tolerant than wild records suggest, which is the usual explanation, and it has not been established for this species.
What would improve this: Corroborate against a second, independent source.
minimum tank volumeSources disagreeAquariumHQ's own position, derived from evidenced inputs.1 citation, 1 independent origin
Sources give values that do not reconcile. Recorded rather than averaged.
- 200 L — AquariumHQ husbandry synthesis · Stated minimum · Recommended for keeping · checked 2026-08-11
- 120 L — Ornamental Aquatic Trade Association · Stated minimum · Recommended for keeping · checked 2026-08-11Corrected on checking from 110 L.
- 75 L — UF/IFAS Extension — fish health and aquaculture publications · Stated minimum · Recommended for keeping
What this kind of claim needs: minimum tank size — no external source is required, provided AquariumHQ shows its reasoning. No authority publishes this. AquariumHQ derives it, and the derivation is recorded with its inputs and assumptions.
What would improve this: Editorial resolution. More reading will not settle this on its own.
minimum tank lengthAquariumHQ's judgement — no authority publishes thisAquariumHQ's own position, derived from evidenced inputs.
No external authority publishes this. The rationale carries the reasoning.
What this kind of claim needs: minimum tank size — no external source is required, provided AquariumHQ shows its reasoning. No authority publishes this. AquariumHQ derives it, and the derivation is recorded with its inputs and assumptions.
What would improve this: Keep the rationale current. There is no source to find.
minimum group sizeAquariumHQ's judgement — no authority publishes thisAquariumHQ's own position, derived from evidenced inputs.
No external authority publishes this. The rationale carries the reasoning.
What this kind of claim needs: group size — no external source is required, provided AquariumHQ shows its reasoning. No external source is required for this class. AquariumHQ's position stands on its stated reasoning.
What would improve this: Keep the rationale current. There is no source to find.
Guides relevant to this species
Chosen from this record's own traits rather than listed on every page.
- Predator and prey sizeIt takes fish that fit in its mouth, and its mouth grows with it.
- Territorial behaviourIt defends ground, and the shape of what it defends decides the tank more than the volume does.
- How to read a compatibility verdictThis animal's fins are a target, and most compatibility verdicts about that are derived rather than observed.
Group size and social behaviour
Juveniles are kept as a group of six or more and allowed to pair naturally. Once a pair forms, the remaining fish are usually driven out and need somewhere else to go — plan for that before buying the group.