Senegal bichir
A living representative of a lineage that predates almost every other fish in this catalogue, with paired lungs and a row of separate dorsal finlets. It breathes air obligately — a bichir prevented from reaching the surface will drown — and it eats anything it can fit in.
Quick profile
- Scientific name
- Polypterus senegalus
- Adult size
- 30–35 cm (11.8–13.8 in)
- Lifespan
- 10–20 years
- Temperature
- 24–29 °C (75–84 °F)
- pH
- 6–8
- Hardness
- 4–20 °dGH
- Minimum tank
- 250 L (66 US gal)
- Minimum length
- 125 cm
- Swimming zone
- Bottom
- Social
- Loose group
- Diet
- Carnivore
- Overall confidence
- moderate confidence
What keeping this species involves
Hardy, extremely long-lived and undemanding about water quality by the standards of a fish this size. What it needs is space, surface access and tankmates it cannot swallow.
Slow, shallow, vegetated and often poorly oxygenated water.
Identity and names
- Common name
- Senegal bichir
- Scientific name
- Polypterus senegalus
- Family
- Polypteridae
- Order
- Polypteriformes
- Class
- Actinopterygii
- Also sold as
- dinosaur eel, Cuvier's bichir, Polypterus senegalus
Adult size and growth
30–35 cm (11.8–13.8 in) — Sold at 8–10 cm. Reaches around 30 cm.
Typical lifespan in an aquarium: 10–20 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: elongate with a large — a piscivore's mouth. Assigned from what is typical of Polypteridae, not examined for this species.
Water and tank requirements
A 30 cm bottom-dwelling fish that must reach the surface regularly: floor area for the animal and a clear path upwards from all of it.
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.
- TemperatureFollows the habitat this animal comes from
- Follows the water this animal is recorded from — lowland floodplain. Lowland floodplain generally runs 22–32°C, and the advised band of 24–29°C is consistent with it. This is AquariumHQ's reasoning from the habitat, not a measurement of the species.
- 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 6–8 is consistent with it. This is AquariumHQ's reasoning from the habitat, not a measurement of the species.
- 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 4–20 dGH is consistent with it. This is AquariumHQ's reasoning from the habitat, not a measurement of the species.
Scale: 20.5 to 33.5 °C.
Scale: 5.7 to 8.3 pH.
Scale: -0.7 to 22.7 dGH.
| Requirement | Value | Notes |
|---|---|---|
| Temperature | 24–29 °C (75–84 °F) | Stability matters more than hitting an exact figure. |
| pH | 6–8 | A stable pH outside the ideal band is usually better than an unstable one inside it. |
| General hardness | 4–20 °dGH | Check your supplier's published figure before choosing species. |
| Minimum volume | 250 L (66 US gal) | A floor, not a recommendation. |
| Minimum footprint | 125 cm long | A 30 cm bottom-dwelling fish that must reach the surface regularly: floor area for the animal and a clear path upwards from all of it. |
| Water flow | low | Match the outflow to this rather than to the filter's rating. |
| Lid required | Yes | This species jumps. |
| Structure | Sand, caves and open floor with an unobstructed route to the surface and an air gap above the water. |
Behaviour
- Rises to the surface at intervals to gulp air into paired lungs.
- Hunts by scent along the bottom, working slowly rather than chasing.
Telling males from females
Males have a broader, thicker anal fin. Reliable only on mature fish.
Feeding
Poor eyesight and a strong sense of smell; it hunts by scent and takes time to find food. Fast tankmates strip a tank before it arrives.
- Diet type
- Carnivore
- Staples
- Frozen prawn, mussel and krill, Earthworm, Sinking carnivore pellets
Breeding
- Strategy
- Egg-depositing among fine plants, the male cupping eggs in the anal fin
- Difficulty
- rarely achieved
- 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 | near-certain | 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 | 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.
- Must be able to reach the surface. A tank filled to the rim with no air gap, or one where cover blocks the route up, is dangerous.
- An escape artist. It leaves through gaps that look far too small and can survive out of water long enough to travel.
- Takes any tankmate that fits its mouth once grown, and its mouth is wide.
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
- Nile basin and West African river systems including the Niger and Chad basins
- Habitat
- Slow, shallow, vegetated and often poorly oxygenated water.
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 |
|---|---|---|
| Introduced | 2 | 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. |
No checklist AquariumHQ holds positively calls this species native anywhere, so the native range above rests on AquariumHQ’s own reading of the literature rather than on a cited checklist.
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 | Polypterus senegalus | Observed / measured | high confidence | Catalogue of Life; GBIF — Global Biodiversity Information Facility |
| native range | Nile basin and West African river systems including the Niger and Chad basins | Observed / measured | moderate confidence | GBIF — Global Biodiversity Information Facility |
| adult size | 30–35 cm | Aquarium-literature consensus | moderate confidence | AquariumHQ husbandry synthesis |
| lifespan | 10–20 years | Aquarium-literature consensus | moderate confidence | AquariumHQ husbandry synthesis |
| temperature | 24–29 °C | Aquarium-literature consensus | moderate confidence | AquariumHQ husbandry synthesis |
| ph | 6–8 pH | Aquarium-literature consensus | moderate confidence | AquariumHQ husbandry synthesis |
| general hardness | 4–20 °dGH | Aquarium-literature consensus | moderate confidence | AquariumHQ husbandry synthesis |
| minimum tank volume | ≥ 250 L | AquariumHQ editorial position | moderate confidence | AquariumHQ husbandry synthesis |
| minimum tank length | ≥ 125 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. 4 distribution statements held from GBIF checklists — introduced in 2 country. 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.
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 loose group, and the number it is kept in decides how it behaves.
- Predator and prey sizeIt takes fish that fit in its mouth, and its mouth grows with it.
- The kinds of water aquarium fish come fromThis record's water bands follow lowland floodplain, which is the kind of water this animal is recorded from.
- Rehoming an animal you can no longer keepThis animal reaches 35 cm. Most of the difficult rehoming cases are fish sold small that were always going to become impossible.
Group size and social behaviour
Tolerant of its own kind at similar sizes. A smaller bichir is food rather than company.