Adolfo's corydoras
A white-bodied corydoras with a black head stripe and an orange patch behind it, from the upper Rio Negro. It is closely similar to two other species sold under overlapping names, and it is a genuine blackwater fish rather than a general community corydoras.
Quick profile
- Scientific name
- Corydoras adolfoi
- Adult size
- 4.5–6 cm (1.8–2.4 in)
- Lifespan
- 5–8 years
- Temperature
- 23–27 °C (73–81 °F)
- pH
- 4.5–6.5
- Hardness
- 0–5 °dGH
- Minimum tank
- 80 L (21 US gal)
- Minimum length
- 80 cm
- Swimming zone
- Bottom
- Social
- Shoaling — at least 6
- Diet
- Omnivore
- Overall confidence
- moderate confidence
What keeping this species involves
Soft acidic water, fine sand and a proper shoal. It is not difficult to feed and it is more particular about chemistry than the corydoras most people have kept.
Small blackwater tributaries over sand and leaf litter, deeply shaded and extremely soft.
Identity and names
- Common name
- Adolfo's corydoras
- Scientific name
- Corydoras adolfoi
- Family
- Callichthyidae
- Order
- Siluriformes
- Class
- Actinopterygii
- Also sold as
- Corydoras adolfoi, adolfoi, Adolfo's cory, false duplicarius
Adult size and growth
4.5–6 cm (1.8–2.4 in)
Typical lifespan in an aquarium: 5–8 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: depressed — flattened top to bottom with a grazing or sucking mouth. Assigned from what is typical of Callichthyidae, not examined for this species.
Water and tank requirements
A shoaling substrate feeder. The floor area is the habitat and the shoal size sets how much of it is needed.
Temperature (°C)
Scale: 0 to 36 °C.
pH (pH)
Scale: 4 to 9.5 pH.
Hardness (°dGH)
Scale: 0 to 30 °dGH.
Why these ranges: Upper Rio Negro blackwater is extremely soft and acidic. This species is markedly less tolerant of hard alkaline water than the bronze or peppered corydoras, and the difference is why it is so often lost slowly in an ordinary community tank.
Where these figures come from
Habitat class
Blackwater
Tannin-stained water draining podzolic forest sand, carrying almost no dissolved mineral and a heavy load of humic and fulvic acid.
The defining property is the absence of mineral, not the colour. Water this soft has almost no buffering, so pH moves fast and a keeper's job is stability rather than chasing the wild figure.
- Conductivity
- 8–40 µS/cm
- Flow
- low
- Dissolved oxygen
- moderate
- 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.
- TemperatureReasoned on this record
- This record states its own reason for this band. See the water section.
- pHReasoned on this record
- This record states its own reason for this band. See the water section.
- General hardnessReasoned on this record
- This record states its own reason for this band. See the water section.
| Requirement | Value | Notes |
|---|---|---|
| Temperature | 23–27 °C (73–81 °F) | Stability matters more than hitting an exact figure. |
| pH | 4.5–6.5 | A stable pH outside the ideal band is usually better than an unstable one inside it. |
| General hardness | 0–5 °dGH | Check your supplier's published figure before choosing species. |
| Minimum volume | 80 L (21 US gal) | A floor, not a recommendation. |
| Minimum footprint | 80 cm long × 35 cm deep | A shoaling substrate feeder. The floor area is the habitat and the shoal size sets how much of it is needed. |
| Water flow | low | Match the outflow to this rather than to the filter's rating. |
| Lid required | Recommended | Reduces evaporation and prevents accidents. |
| Structure | Fine soft sand, leaf litter and wood with dim lighting. Botanicals hold the water chemistry as well as providing cover. |
Behaviour
- Sifts mouthfuls of sand and expels them through the gill openings, working forward in short bursts.
- Rises to the surface to gulp air at intervals, which is intestinal respiration and is normal rather than a sign of poor water.
Telling males from females
Females are broader across the body when viewed from above and slightly larger. The difference is only readable in mature fish.
Feeding
Sifts sand for invertebrates and detritus. It needs food that reaches the substrate and cannot survive on what other fish leave.
- Diet type
- Omnivore
- Staples
- Sinking pellets, Frozen bloodworm, Live blackworm, Frozen daphnia
Breeding
- Strategy
- Eggs placed on hard surfaces by the female after a T-position pairing
- Difficulty
- challenging
- Parental care
- none
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. |
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 interchangeably with Corydoras duplicareus and Corydoras imitator, which differ in the width of the black stripe. Their care overlaps closely enough that the confusion is not dangerous, and the price difference between them is substantial.
- Sharp gravel wears down the barbels, after which the fish cannot feed properly. Barbel loss is the clearest single indicator of an unsuitable substrate.
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
- Brazil — the upper Rio Negro around São Gabriel da Cachoeira
- Habitat
- Small blackwater tributaries over sand and leaf litter, deeply shaded and extremely soft.
What the checklists say
4 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 | 1 | A checklist states the species occurs here naturally. |
| Introduced | 1 | 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 | 2 | 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 adolfoi | Observed / measured | high confidence | Catalogue of Life; GBIF — Global Biodiversity Information Facility |
| native range | Brazil — the upper Rio Negro around São Gabriel da Cachoeira | Observed / measured | moderate confidence | GBIF — Global Biodiversity Information Facility |
| adult size | 4.5–6 cm | Aquarium-literature consensus | moderate confidence | AquariumHQ husbandry synthesis |
| lifespan | 5–8 years | Aquarium-literature consensus | moderate confidence | AquariumHQ husbandry synthesis |
| temperature | 23–27 °C | Aquarium-literature consensus | moderate confidence | AquariumHQ husbandry synthesis |
| ph | 4.5–6.5 pH | Aquarium-literature consensus | moderate confidence | AquariumHQ husbandry synthesis |
| general hardness | 0–5 °dGH | Aquarium-literature consensus | moderate confidence | AquariumHQ husbandry synthesis |
| minimum tank volume | ≥ 80 L | AquariumHQ editorial position | moderate confidence | AquariumHQ husbandry synthesis |
| minimum tank length | ≥ 80 cm | AquariumHQ editorial position | moderate confidence | AquariumHQ husbandry synthesis |
| minimum group size | ≥ 6 | 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 2026-08-29. 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. 4 distribution statements held from GBIF checklists — native in 1, introduced in 1 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.
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.
- Schooling and shoalingThis species is recorded as shoal, and the number it is kept in decides how it behaves.
- Wild conditions and aquarium recommendationsThe water band on this page is an AquariumHQ position with a stated reason, not a measurement of a river.
Group size and social behaviour
Shoals with its own species and joins mixed corydoras groups less readily than the common species do. A group of six of one species behaves better than six of six.