Severum
A deep-bodied, disc-shaped cichlid sometimes sold as a hardy substitute for discus, which it is not — it is larger, less demanding about water and considerably more likely to eat the planting. Uniquely among the large New World cichlids here it is a mouthbrooder.
Quick profile
- Scientific name
- Heros severus
- Adult size
- 20–25 cm (7.9–9.8 in)
- Lifespan
- 10–15 years
- Temperature
- 24–29 °C (75–84 °F)
- pH
- 5.5–7
- Hardness
- 1–12 °dGH
- Minimum tank
- 300 L (79 US gal)
- Minimum length
- 120 cm
- Swimming zone
- Midwater
- Social
- Pair
- Diet
- Omnivore
- Overall confidence
- low confidence
What keeping this species involves
Hardy and very long-lived. The commitment is the size and the decade or more it will occupy the tank.
Slow blackwater and clearwater river margins with submerged wood.
Identity and names
- Common name
- Severum
- Scientific name
- Heros severus
- Family
- Cichlidae
- Order
- Cichliformes
- Class
- Actinopterygii
- Also sold as
- banded cichlid, Heros severus, gold severum
Name ambiguity
Heros is an unresolved group and much of what is sold as 'severum' is one of several undescribed or recently separated species. The gold and red strains are captive colour forms rather than distinct species.
Adult size and growth
20–25 cm (7.9–9.8 in) — Sold at 4–5 cm. Reaches around 20 cm and is deep-bodied with it.
Typical lifespan in an aquarium: 10–15 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.
Water and tank requirements
A deep-bodied 20 cm fish needs height as well as length — one of the few records where vertical space genuinely matters — and a pair needs a defensible area within it.
| Requirement | Value | Notes |
|---|---|---|
| Temperature | 24–29 °C (75–84 °F) | Stability matters more than hitting an exact figure. |
| pH | 5.5–7 | A stable pH outside the ideal band is usually better than an unstable one inside it. |
| General hardness | 1–12 °dGH | Check your supplier's published figure before choosing species. |
| Minimum volume | 300 L (79 US gal) | A floor, not a recommendation. |
| Minimum footprint | 120 cm long | A deep-bodied 20 cm fish needs height as well as length — one of the few records where vertical space genuinely matters — and a pair needs a defensible area within it. |
| 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 wood structure, dim light and tannin-stained water. Soft plants are eaten. |
Behaviour
- Uses the middle and upper water rather than the floor, unusually for a large cichlid.
- Grazes soft plant material persistently.
Telling males from females
Males develop facial markings and longer fin extensions with age. Juveniles cannot be sexed reliably.
Feeding
Substantially herbivorous. A protein-only diet is associated with digestive problems.
- Diet type
- Omnivore
- Staples
- Sinking cichlid pellets, Blanched vegetables, Frozen mysis and prawn
Breeding
- Strategy
- Mouthbrooding, unusually for the group
- Difficulty
- challenging
- Parental care
- mouthbrooding
Heros severus in the strict sense broods in the mouth; the species sold alongside it under the same name are substrate spawners, which is one way to tell what you actually have.
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 | moderate | 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 | consumes | 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 4 cm as a community fish and reaches 20 cm with a body deep enough to need real height. Very few tanks it is sold into can hold an adult.
- Eats soft plants. Keeping it and keeping a planted tank are alternatives.
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
- Upper Rio Negro and Orinoco drainages
- Habitat
- Slow blackwater and clearwater river margins with submerged wood.
What the checklists say
16 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 | 3 | A checklist states the species occurs here naturally. |
| Introduced | 4 | 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 | 9 | 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 | Heros severus | Observed / measured | high confidence | Catalogue of Life; GBIF — Global Biodiversity Information Facility |
| native range | Upper Rio Negro and Orinoco drainages | Observed / measured | moderate confidence | GBIF — Global Biodiversity Information Facility |
| adult size | 20–25 cm | Aquarium-literature consensus | low confidence | AquariumHQ husbandry synthesis |
| lifespan | 10–15 years | Aquarium-literature consensus | low confidence | AquariumHQ husbandry synthesis |
| temperature | 24–29 °C | Aquarium-literature consensus | low confidence | AquariumHQ husbandry synthesis |
| ph | 5.5–7 pH | Aquarium-literature consensus | low confidence | AquariumHQ husbandry synthesis |
| general hardness | 1–12 °dGH | Aquarium-literature consensus | low confidence | AquariumHQ husbandry synthesis |
| minimum tank volume | ≥ 300 L | AquariumHQ editorial position | moderate confidence | AquariumHQ husbandry synthesis |
| minimum tank length | ≥ 120 cm | AquariumHQ editorial position | moderate 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 2026-08-12. 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. 16 distribution statements held from GBIF checklists — native in 3, introduced in 4 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 sizeAquariumHQ'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: size a well-kept specimen reaches — 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.
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.
temperatureAquariumHQ'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.
phAquariumHQ'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.
general hardnessAquariumHQ'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.
minimum tank volumeAquariumHQ'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 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.
Group size and social behaviour
Pairs from a growing group. Adults introduced to each other as strangers often do not settle.