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FishfreshwaterUndemanding

Bolivian ram

Larger, plainer and vastly more forgiving than the German blue ram — tolerant of ordinary temperatures and ordinary tap water, and long-lived with it. The dwarf cichlid to start with.

Quick profile

Scientific name
Mikrogeophagus altispinosus
Adult size
7–9 cm (2.8–3.5 in)
Lifespan
4–6 years
Temperature
22–28 °C (72–82 °F)
pH
6–7.8
Hardness
2–15 °dGH
Minimum tank
110 L (29 US gal)
Minimum length
80 cm
Swimming zone
Bottom
Social
Pair
Diet
Omnivore
Overall confidence
high confidence

What keeping this species involves

Hardy across normal community temperatures and hardness, unlike its more colourful relative.

Shallow, sandy, slow-flowing tributaries and pools.

Identity and names

Common name
Bolivian ram
Scientific name
Mikrogeophagus altispinosus
Family
Cichlidae
Order
Cichliformes
Class
Actinopterygii

Adult size and growth

7–9 cm (2.8–3.5 in)

Typical lifespan in an aquarium: 4–6 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 pair holding a substrate territory, with the tank space for other fish to stay out of it.

RequirementValueNotes
Temperature22–28 °C (72–82 °F)Stability matters more than hitting an exact figure.
pH6–7.8A stable pH outside the ideal band is usually better than an unstable one inside it.
General hardness2–15 °dGHCheck your supplier's published figure before choosing species.
Minimum volume110 L (29 US gal)A floor, not a recommendation.
Minimum footprint80 cm longA pair holding a substrate territory, with the tank space for other fish to stay out of it.
Water flowlowMatch the outflow to this rather than to the filter's rating.
Lid requiredRecommendedReduces evaporation and prevents accidents.
StructureFine sand, flat stones and cover.

Group size and social behaviour

Kept as a pair or singly; pairs form readily from a group of juveniles.

Structure
Pair

Behaviour

  • Sifts mouthfuls of sand constantly — sharp gravel prevents the behaviour and damages the mouth.

Telling males from females

Males are larger with more extended fin filaments; sexing juveniles is unreliable.

Feeding

Diet type
Omnivore
Staples
Frozen bloodworm and daphnia, Sinking granules, Live foods

Breeding

Strategy
Substrate spawner; both parents guard
Difficulty
straightforward
Parental care
guarding

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.

Risk this species poses to common tankmates
TowardsRiskWhat it means
Small fishlowAnything that fits in the mouth is at risk once this species reaches adult size.
Adult dwarf shrimphighCover reduces losses but rarely prevents them where the risk is high.
Shrimpletsnear-certainDetermines whether a shrimp colony can grow rather than merely persist.
SnailslowApplies to snails you wanted as well as snails you did not.
Long or trailing finsoccasionalFin damage is an entry point for secondary infection.
PlantsnoneTough 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.

  • Needs sand. This is a functional requirement, not an aesthetic one.

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 Madeira basin — Bolivia and western Brazil
Habitat
Shallow, sandy, slow-flowing tributaries and pools.

What the checklists say

8 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.

StatusPlacesWhat this means
Native2A checklist states the species occurs here naturally.
Introduced2A 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 stated4The 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.

ClaimValueEvidence typeConfidenceSource
scientific nameMikrogeophagus altispinosusObserved / measuredhigh confidenceCatalogue of Life; GBIF — Global Biodiversity Information Facility
native rangeUpper Madeira basin — Bolivia and western BrazilObserved / measuredmoderate confidenceGBIF — Global Biodiversity Information Facility
adult size7–9 cmAquarium-literature consensushigh confidenceAquariumHQ husbandry synthesis
lifespan4–6 yearsAquarium-literature consensushigh confidenceAquariumHQ husbandry synthesis
temperature22–28 °CAquarium-literature consensushigh confidenceAquariumHQ husbandry synthesis
ph6–7.8 pHAquarium-literature consensushigh confidenceAquariumHQ husbandry synthesis
general hardness2–15 °dGHAquarium-literature consensushigh confidenceAquariumHQ husbandry synthesis
minimum tank volume≥ 110 LAquariumHQ editorial positionmoderate confidenceAquariumHQ husbandry synthesis
minimum tank length≥ 80 cmAquariumHQ editorial positionmoderate confidenceAquariumHQ 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. 8 distribution statements held from GBIF checklists — native in 2, introduced in 2 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.

  • 5.6 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.

temperatureOne sourceAquariumHQ's own position, derived from evidenced inputs.1 citation, 1 independent origin

A single source: fishbase.

  • 22–26 °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. Derived from the observed range rather than copied from it. AquariumHQ advises 22–28 °C; FishBase records 22–26 °C. Lower bounds agree. The Bolivian ram is the cooler-water species of the two rams and the advice already reflects that; two degrees of headroom at the top is ordinary keeping latitude.

What would improve this: Corroborate against a second, independent source.

phPublished with one end of the range missingAquariumHQ's own position, derived from evidenced inputs.

A source published one end of the range and left the other unstated.

At least 7 pH — the source does not state an upper boundFishBase gives the pH range as "7.0 - ?". The lower bound is published and the upper is not, so this is recorded as a constraint — at least pH 7.0 — rather than completed with an invented ceiling.

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: Find a source that publishes the missing bound. Do not infer it.

general hardnessPublished with one end of the range missingAquariumHQ's own position, derived from evidenced inputs.

A source published one end of the range and left the other unstated.

At least 10 dGH — the source does not state an upper boundFishBase gives the dH range as "10 - ?". The lower bound is published and the upper is not, so this is recorded as a constraint — at least 10 dGH — rather than completed with an invented ceiling.

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: Find a source that publishes the missing bound. Do not infer it.

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.