Queen loach
A gold-and-black barred loach from the Ganges drainage, subtropical rather than tropical, and among the more assertive mid-sized botiids. It sparks a strong hierarchy and needs a group large enough to absorb it.
Quick profile
- Scientific name
- Botia dario
- Adult size
- 10–15 cm (3.9–5.9 in)
- Lifespan
- 8–12 years
- Temperature
- 20–26 °C (68–79 °F)
- pH
- 6.5–7.5
- Hardness
- 4–12 °dGH
- Minimum tank
- 200 L (53 US gal)
- Minimum length
- 120 cm
- Swimming zone
- Bottom
- Social
- Loose group — at least 5
- Diet
- Omnivore
- Overall confidence
- moderate confidence
What keeping this species involves
Hardy and straightforward to feed. What it needs is a group, a long tank and cooler water than most tropical communities provide.
Clear flowing rivers and streams over sand and gravel in the Himalayan foothills, cooling substantially in winter.
Identity and names
- Common name
- Queen loach
- Scientific name
- Botia dario
- Family
- Botiidae
- Order
- Cypriniformes
- Class
- Actinopterygii
- Also sold as
- Botia dario, Bengal loach, geto loach, dario loach
Adult size and growth
10–15 cm (3.9–5.9 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: fusiform — the ordinary torpedo with a small terminal mouth. Assigned from what is typical of Botiidae, not examined for this species.
Water and tank requirements
A group of assertive loaches. The floor area is what allows a subordinate fish to be out of the dominant one's line of sight.
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: Himalayan foothill rivers with a genuine cool season. The upper bound is set below the usual community figure because sustained warmth is associated with shorter lives across the subtropical botiids.
Where these figures come from
Habitat class
Hill stream and rapids
Fast, cool, oxygen-saturated running water over rock and gravel, typically at altitude or on a steep gradient.
Oxygen and flow are the requirement, not the chemistry. A hill-stream species in still water at the right pH is being kept badly, and the failure is slow enough that the keeper usually blames something else.
- Conductivity
- 50–300 µS/cm
- Flow
- high
- Dissolved oxygen
- near saturation
- 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 | 20–26 °C (68–79 °F) | Stability matters more than hitting an exact figure. |
| pH | 6.5–7.5 | A stable pH outside the ideal band is usually better than an unstable one inside it. |
| General hardness | 4–12 °dGH | Check your supplier's published figure before choosing species. |
| Minimum volume | 200 L (53 US gal) | A floor, not a recommendation. |
| Minimum footprint | 120 cm long × 40 cm deep | A group of assertive loaches. The floor area is what allows a subordinate fish to be out of the dominant one's line of sight. |
| Water flow | moderate | Match the outflow to this rather than to the filter's rating. |
| Lid required | Recommended | Reduces evaporation and prevents accidents. |
| Structure | Gravel and rounded stone with numerous caves and crevices, and smooth areas of sand for foraging. |
Behaviour
- Chases within the group in short bursts that establish rank and then subside.
- Turns on its side or lies flat to rest, which is normal loach behaviour and is regularly reported as a dying fish.
Telling males from females
No reliable external difference.
Feeding
An invertebrate feeder that takes prepared food readily and works the substrate persistently.
- Diet type
- Omnivore
- Staples
- Sinking pellets, Frozen bloodworm, Snails, Frozen daphnia
Breeding
- Strategy
- Not achieved in home aquaria; commercial stock is induced
- 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 | none | Anything that fits in the mouth is at risk once this species reaches adult size. |
| Adult dwarf shrimp | high | 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 | near-certain | Applies to snails you wanted as well as snails you did not. |
| Long or trailing fins | occasional | 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.
- Whitespot treatment at full dose is risky, as with the other botiids. Reduced dosing with close observation is the common approach.
- Sold as a small colourful loach and reaching fifteen centimetres. The barring fades with age and the adult is a plainer animal.
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
- Northern India, Bangladesh and Nepal — the Ganges and Brahmaputra drainages
- Habitat
- Clear flowing rivers and streams over sand and gravel in the Himalayan foothills, cooling substantially in winter.
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 | Botia dario | Observed / measured | high confidence | Catalogue of Life; GBIF — Global Biodiversity Information Facility |
| native range | Northern India, Bangladesh and Nepal — the Ganges and Brahmaputra drainages | Observed / measured | moderate confidence | GBIF — Global Biodiversity Information Facility |
| adult size | 10–15 cm | Aquarium-literature consensus | moderate confidence | AquariumHQ husbandry synthesis |
| lifespan | 8–12 years | Aquarium-literature consensus | moderate confidence | AquariumHQ husbandry synthesis |
| temperature | 20–26 °C | Aquarium-literature consensus | moderate confidence | AquariumHQ husbandry synthesis |
| ph | 6.5–7.5 pH | Aquarium-literature consensus | moderate confidence | AquariumHQ husbandry synthesis |
| general hardness | 4–12 °dGH | Aquarium-literature consensus | moderate confidence | AquariumHQ husbandry synthesis |
| minimum tank volume | ≥ 200 L | AquariumHQ editorial position | moderate confidence | AquariumHQ husbandry synthesis |
| minimum tank length | ≥ 120 cm | AquariumHQ editorial position | moderate confidence | AquariumHQ husbandry synthesis |
| minimum group size | ≥ 5 | 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.
- Predator and prey sizeIt takes adult dwarf shrimp, which decides what can share the tank.
- Wild conditions and aquarium recommendationsThe water band on this page is an AquariumHQ position with a stated reason, not a measurement of a river.
- How to read a compatibility verdictThis animal is recorded as nipping fins, which is one of the few compatibility factors with real reports behind it.
Group size and social behaviour
Establishes a firm hierarchy through chasing and display. Below five the dominant fish has one target and does not stop.