Black kuhli loach
An unbanded chocolate-brown kuhli loach, sold alongside the striped species and often assumed to be a colour form of them. It is a separate species with the same burrowing habits and the same absolute need for soft substrate and company.
Quick profile
- Scientific name
- Pangio oblonga
- Adult size
- 7–9 cm (2.8–3.5 in)
- Lifespan
- 8–12 years
- Temperature
- 23–28 °C (73–82 °F)
- pH
- 5.5–7
- Hardness
- 1–8 °dGH
- Minimum tank
- 60 L (16 US gal)
- Minimum length
- 60 cm
- Swimming zone
- Bottom
- Social
- Loose group — at least 6
- Diet
- Micropredator
- Overall confidence
- moderate confidence
What keeping this species involves
Peaceful, hardy and long-lived, needing soft substrate, a group and food that reaches the floor. None of that is difficult and all of it is regularly not provided.
Slow shaded forest streams and swamp margins over silt and leaf litter, in soft acidic water.
Identity and names
- Common name
- Black kuhli loach
- Scientific name
- Pangio oblonga
- Family
- Cobitidae
- Order
- Cypriniformes
- Class
- Actinopterygii
- Also sold as
- Pangio oblonga, Acanthophthalmus javanicus, chocolate kuhli, black eel loach
- Former or synonymous names
- Acanthophthalmus javanicus, Pangio javanicus
Adult size and growth
7–9 cm (2.8–3.5 in)
Typical lifespan in an aquarium: 8–12 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: eel-like with a small terminal mouth. As the kuhli loach.
Water and tank requirements
A burrowing group species. The floor area supports the group and the sand depth matters more than the volume above it.
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: Shaded lowland forest streams across a wide Asian range, soft and acidic. The species tolerates harder water and is found in soft, and the band follows the habitat.
Where these figures come from
Habitat class
Soft forest stream
Shaded, mineral-poor running water under forest canopy, with leaf litter and moderate tannin loading but without true blackwater chemistry.
The commonest habitat class in the aquarium trade and the one the conventional community-tank setting actually fits. Soft and slightly acidic, without the extremes that make blackwater difficult.
- Conductivity
- 20–120 µS/cm
- Flow
- low
- Dissolved oxygen
- moderate
- Seasonality
- moderate
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 | 23–28 °C (73–82 °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 | 1–8 °dGH | Check your supplier's published figure before choosing species. |
| Minimum volume | 60 L (16 US gal) | A floor, not a recommendation. |
| Minimum footprint | 60 cm long × 35 cm deep | A burrowing group species. The floor area supports the group and the sand depth matters more than the volume above 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 | Soft sand deep enough to bury in, leaf litter, wood and dense planting. Dim light brings the fish out during the day. |
Behaviour
- Buries in sand and under leaf litter through the day, emerging in numbers after dark.
- Occasionally swims in loose vertical spirals through open water, usually before a change in weather or after a large water change.
Telling males from females
Females are broader across the body when mature and the ovaries are sometimes visible through the flank. Males have a thicker second pectoral ray.
Feeding
Sifts substrate for small invertebrates and detritus. It feeds at night and is easily out-competed during the day.
- Diet type
- Micropredator
- Staples
- Sinking micro pellets, Frozen bloodworm, Frozen daphnia, Live blackworm
Breeding
- Strategy
- Eggs scattered among plant roots near the surface
- Difficulty
- rarely achieved
- Parental care
- none
Occasional aquarium spawnings are reported and are not reliably repeatable. Most trade stock is wild-caught.
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.
- Carries a small erectile spine beneath the eye that catches in nets. Move it in a container rather than lifting it out.
- Coarse gravel prevents burrowing entirely and can trap the fish. Sand is a requirement for every Pangio in this catalogue.
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
- India, Bangladesh, Myanmar, the Malay Peninsula, Sumatra, Java and Borneo
- Habitat
- Slow shaded forest streams and swamp margins over silt and leaf litter, in soft acidic water.
What the checklists say
3 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 |
|---|---|---|
| Recorded as present, establishment means not stated | 3 | 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 | Pangio oblonga | Observed / measured | high confidence | Catalogue of Life; GBIF — Global Biodiversity Information Facility |
| native range | India, Bangladesh, Myanmar, the Malay Peninsula, Sumatra, Java and Borneo | Observed / measured | moderate confidence | GBIF — Global Biodiversity Information Facility |
| adult size | 7–9 cm | Aquarium-literature consensus | moderate confidence | AquariumHQ husbandry synthesis |
| lifespan | 8–12 years | Aquarium-literature consensus | moderate confidence | AquariumHQ husbandry synthesis |
| temperature | 23–28 °C | Aquarium-literature consensus | moderate confidence | AquariumHQ husbandry synthesis |
| ph | 5.5–7 pH | Aquarium-literature consensus | moderate confidence | AquariumHQ husbandry synthesis |
| general hardness | 1–8 °dGH | Aquarium-literature consensus | moderate confidence | AquariumHQ husbandry synthesis |
| minimum tank volume | ≥ 60 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 | 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 checkableLimited evidence — treat with caution.
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. 3 distribution statements held, and not one of them states an establishment means. Presence without native-or-introduced is not a native-range claim, so this stays below requirement rather than being read as one.
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 loose group, and the number it is kept in decides how it behaves.
- Scientific and trade namesThis species has been published under more than one accepted name.
- 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
Strongly gregarious and largely invisible in small numbers. A group of six or more is what turns a hidden fish into a visible one.