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FishfreshwaterModerate

Polka dot loach

Described only in 2004 and among the more strikingly marked loaches, with a pattern that changes substantially between juvenile and adult. It comes from fast water and shows it: this is a loach that wants current rather than a still planted tank.

Quick profile

Scientific name
Botia kubotai
Adult size
10–13 cm (3.9–5.1 in)
Lifespan
8–12 years
Temperature
23–27 °C (73–81 °F)
pH
6.5–7.5
Hardness
3–12 °dGH
Minimum tank
180 L (48 US gal)
Minimum length
120 cm
Swimming zone
Bottom
Social
Shoaling — at least 5
Diet
Omnivore
Overall confidence
low confidence

What keeping this species involves

Needs flow, oxygen and numbers. Given those it is hardy; without them it is a fish that hides and slowly loses condition.

Clear, fast, oxygen-rich streams over rock and gravel.

Identity and names

Common name
Polka dot loach
Scientific name
Botia kubotai
Family
Botiidae
Order
Cypriniformes
Class
Actinopterygii
Also sold as
Burmese border loach, angelicus botia, Botia kubotai

Adult size and growth

10–13 cm (3.9–5.1 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.

Water and tank requirements

A group patrols the whole base and needs both length and a set of caves; the current it needs also requires run to develop.

RequirementValueNotes
Temperature23–27 °C (73–81 °F)Stability matters more than hitting an exact figure.
pH6.5–7.5A stable pH outside the ideal band is usually better than an unstable one inside it.
General hardness3–12 °dGHCheck your supplier's published figure before choosing species.
Minimum volume180 L (48 US gal)A floor, not a recommendation.
Minimum footprint120 cm longA group patrols the whole base and needs both length and a set of caves; the current it needs also requires run to develop.
Water flowhighMatch the outflow to this rather than to the filter's rating.
Lid requiredRecommendedReduces evaporation and prevents accidents.
StructureSmooth rounded stone, driftwood and strong flow. Oxygen saturation matters more here than for most loaches.

Group size and social behaviour

Strongly social and hierarchical. Below about five, dominance falls on one or two fish continuously.

Structure
Shoaling
Minimum group
5

Behaviour

  • Works against the current rather than avoiding it.
  • The juvenile pattern of pale blotches breaks up into a finer reticulation with age, so adults look like a different fish.

Feeding

Diet type
Omnivore
Staples
Sinking pellets, Frozen bloodworm and mysis, Blanched vegetables
Supplements
Snails

Breeding

Strategy
Not achieved in home aquaria
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.

Risk this species poses to common tankmates
TowardsRiskWhat it means
Small fishnoneAnything 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.
Snailsnear-certainApplies 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.

  • A still, warm, heavily planted tank is the wrong environment; this species comes from fast, cool, oxygen-rich water.
  • Sensitive to ich medications at standard dose, in common with other scaleless-appearing loaches.

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
Ataran river system on the Thailand–Myanmar border
Habitat
Clear, fast, oxygen-rich streams over rock and gravel.

What the checklists say

2 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
Recorded as present, establishment means not stated2The 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.

ClaimValueEvidence typeConfidenceSource
scientific nameBotia kubotaiObserved / measuredhigh confidenceCatalogue of Life; GBIF — Global Biodiversity Information Facility
native rangeAtaran river system on the Thailand–Myanmar borderObserved / measuredmoderate confidenceGBIF — Global Biodiversity Information Facility
adult size10–13 cmAquarium-literature consensuslow confidenceAquariumHQ husbandry synthesis
lifespan8–12 yearsAquarium-literature consensuslow confidenceAquariumHQ husbandry synthesis
temperature23–27 °CAquarium-literature consensuslow confidenceAquariumHQ husbandry synthesis
ph6.5–7.5 pHAquarium-literature consensuslow confidenceAquariumHQ husbandry synthesis
general hardness3–12 °dGHAquarium-literature consensuslow confidenceAquariumHQ husbandry synthesis
minimum tank volume≥ 180 LAquariumHQ editorial positionmoderate confidenceAquariumHQ husbandry synthesis
minimum tank length≥ 120 cmAquariumHQ editorial positionmoderate confidenceAquariumHQ husbandry synthesis
minimum group size≥ 5AquariumHQ editorial positionlow 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 2026-08-12. 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 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. 2 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.