Bronze corydoras
The most widely kept corydoras, and the one most often kept wrongly — in twos or threes, on gravel. It is a social sand-sifter that needs a group and a substrate it can push its face into.
Quick profile
- Scientific name
- Corydoras aeneus
- Adult size
- 6–7 cm (2.4–2.8 in)
- Lifespan
- 5–10 years
- Temperature
- 22–26 °C (72–79 °F)
- pH
- 6–7.8
- Hardness
- 2–18 °dGH
- Minimum tank
- 75 L (20 US gal)
- Minimum length
- 60 cm
- Swimming zone
- Bottom
- Social
- Shoaling — at least 6
- Diet
- Omnivore
- Overall confidence
- high confidence
What keeping this species involves
Hardy and long-lived given sand, a group and its own food.
Shallow, slow, soft-bottomed streams and margins.
Identity and names
- Common name
- Bronze corydoras
- Scientific name
- Corydoras aeneus
- Family
- Callichthyidae
- Order
- Siluriformes
- Class
- Actinopterygii
- Also sold as
- bronze cory, green cory, aeneus cory, Osteogaster aenea
Name ambiguity
'Corydoras aeneus' as sold covers a complex of similar populations, several of which have since been described separately or moved to other genera. Husbandry across the complex is essentially the same.
Adult size and growth
6–7 cm (2.4–2.8 in)
Typical lifespan in an aquarium: 5–10 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
Floor area rather than volume: a group of six forages across the bottom together and needs the width as much as the length.
| Requirement | Value | Notes |
|---|---|---|
| Temperature | 22–26 °C (72–79 °F) | Stability matters more than hitting an exact figure. |
| pH | 6–7.8 | A stable pH outside the ideal band is usually better than an unstable one inside it. |
| General hardness | 2–18 °dGH | Check your supplier's published figure before choosing species. |
| Minimum volume | 75 L (20 US gal) | A floor, not a recommendation. |
| Minimum footprint | 60 cm long × 30 cm deep | Floor area rather than volume: a group of six forages across the bottom together and needs the width as much as the length. |
| Water flow | moderate | Match the outflow to this rather than to the filter's rating. |
| Lid required | Recommended | Reduces evaporation and prevents accidents. |
| Structure | Soft sand and shaded cover. Gravel prevents normal feeding and erodes the barbels. |
Behaviour
- Darts to the surface to gulp air and absorb oxygen through the gut — normal, and not a sign of poor water quality unless it becomes constant.
- Sifts mouthfuls of sand and expels it through the gills.
Telling males from females
Females are broader and larger when viewed from above.
Feeding
Not a scavenger and not a clean-up crew. Corydoras need their own food and will starve slowly in a tank where the leftovers are assumed to be enough.
- Diet type
- Omnivore
- Staples
- Sinking pellets and wafers, Frozen bloodworm and daphnia, Live blackworm
Breeding
- Strategy
- Eggs deposited on glass and plants after a T-position spawning embrace
- Difficulty
- straightforward
- Parental care
- none
A cool water change often triggers spawning, mimicking the onset of the rainy season.
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 | none | Anything that fits in the mouth is at risk once this species reaches adult size. |
| Adult dwarf shrimp | none | Cover reduces losses but rarely prevents them where the risk is high. |
| Shrimplets | moderate | Determines whether a shrimp colony can grow rather than merely persist. |
| Snails | none | Applies to snails you wanted as well as snails you did not. |
| Long or trailing fins | none | 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.
- Sharp gravel wears down the barbels; once eroded they do not fully recover and feeding is impaired.
- Sensitive to salt and to copper-based treatments.
- Discus tanks at 29–31 °C are too warm for this species, despite the two being frequently recommended together.
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
- Widespread in South America east of the Andes
- Habitat
- Shallow, slow, soft-bottomed streams and margins.
What the checklists say
19 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 | 11 | A checklist states the species occurs here naturally. |
| Introduced | 3 | 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 | 5 | 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 | Corydoras aeneus | Observed / measured | high confidence | Catalogue of Life; GBIF — Global Biodiversity Information Facility |
| native range | Widespread in South America east of the Andes | Observed / measured | moderate confidence | GBIF — Global Biodiversity Information Facility |
| adult size | 6–7 cm | Aquarium-literature consensus | high confidence | AquariumHQ husbandry synthesis |
| lifespan | 5–10 years | Aquarium-literature consensus | high confidence | AquariumHQ husbandry synthesis |
| temperature | 22–26 °C | Aquarium-literature consensus | high confidence | AquariumHQ husbandry synthesis |
| ph | 6–7.8 pH | Aquarium-literature consensus | high confidence | AquariumHQ husbandry synthesis |
| general hardness | 2–18 °dGH | Aquarium-literature consensus | high confidence | AquariumHQ husbandry synthesis |
| minimum tank volume | ≥ 75 L | AquariumHQ editorial position | moderate confidence | AquariumHQ husbandry synthesis |
| minimum tank length | ≥ 60 cm | AquariumHQ editorial position | moderate confidence | AquariumHQ husbandry synthesis |
| minimum group size | ≥ 6 | 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 2026-08-12. 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. 19 distribution statements held from GBIF checklists — native in 11, introduced in 3 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 sizeOne sourceBased on a verified authoritative source.1 citation, 1 independent origin
A single source: fishbase.
- 7.5–7.5 cm — FishBase · Maximum recorded · The range the species is recorded from · checked 2026-08-11
What this kind of claim needs: size a well-kept specimen reaches — no external source is required, provided AquariumHQ shows its reasoning. One authoritative source, which is what this kind of claim requires. Independent replication would be welcome and is not the standard.
What would improve this: Corroborate against a second, independent source.
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.
- 22–26 °C — AquariumHQ husbandry synthesis · Recommended for keeping · Recommended for keeping · checked 2026-08-11
- 25–28 °C — FishBase · Tolerated range · The range the species is recorded from · checked 2026-08-11Corrected on checking from 20–28 °C.
- 22–27 °C — Ornamental Aquatic Trade Association · Recommended for keeping · Recommended for keeping · checked 2026-08-11Corrected on checking from 22–26 °C.
- 17–27 °C — Ornamental Aquatic Trade Association · Recommended for keeping · Recommended for keeping · checked 2026-08-11
- 72–79 °F — UF/IFAS Extension — fish health and aquaculture publications · Recommended for keeping · Recommended for keeping
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.
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.
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.
Group size and social behaviour
Genuinely social. Groups of six or more forage as a unit, rest together and are visibly more active than pairs.