FishfreshwaterDemanding

Denison's barb

A powerful torpedo-shaped barb that needs current, oxygen and a great deal of length. Heavy collection for the aquarium trade contributed to its decline in the wild, and it is assessed as threatened.

Quick profile

Scientific name: Sahyadria denisonii
Adult size: 11–15 cm (4.3–5.9 in)
Lifespan: 5–8 years
Temperature: 18–25 °C (64–77 °F)
pH: 6.5–7.8
Hardness: 3–15 °dGH
Minimum tank: 350 L (92 US gal)
Minimum length: 150 cm
Swimming zone: Midwater
Social: Shoaling — at least 6
Diet: Omnivore
Overall confidence: moderate confidence

What keeping this species involves

Needs cool, fast, well-oxygenated water and a very large tank. Almost always sold into conditions that cannot support the adult.

Fast, cool, highly oxygenated hill rivers over rock and gravel.

Identity and names

Common name: Denison's barb
Scientific name: Sahyadria denisonii
Family: Cyprinidae
Order: Cypriniformes
Class: Actinopterygii
Also sold as: roseline shark, red-line torpedo barb, Miss Kerala
Former or synonymous names: Puntius denisonii

Adult size and growth

11–15 cm (4.3–5.9 in)

Typical lifespan in an aquarium: 5–8 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 shoal of six fish reaching 15 cm that swim continuously against current. Nothing under 150 cm is defensible for adults, and this species is routinely sold into 100 cm tanks.

Requirement	Value	Notes
Temperature	18–25 °C (64–77 °F)	Stability matters more than hitting an exact figure.
pH	6.5–7.8	A stable pH outside the ideal band is usually better than an unstable one inside it.
General hardness	3–15 °dGH	Check your supplier's published figure before choosing species.
Minimum volume	350 L (92 US gal)	A floor, not a recommendation.
Minimum footprint	150 cm long × 50 cm deep	A shoal of six fish reaching 15 cm that swim continuously against current. Nothing under 150 cm is defensible for adults, and this species is routinely sold into 100 cm tanks.
Water flow	high	Match the outflow to this rather than to the filter's rating.
Lid required	Yes	This species jumps.

Behaviour

Swims constantly against flow; a still tank leaves it listless.

Feeding

Diet type: Omnivore
Staples: Dry foods, Frozen bloodworm and brine shrimp, Vegetable matter

Breeding

Strategy: Egg-scattering in cool flowing water
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
Towards	Risk	What it means
Small fish	low	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	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.

Wild populations declined under collection pressure for the aquarium trade; prefer captive-bred stock.
Regularly sold as a 6 cm juvenile with no mention of the adult size or the flow requirement.

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: Western Ghats rivers, Kerala and Karnataka, India
Habitat: Fast, cool, highly oxygenated hill rivers over rock and gravel.

Legal status and responsible practice

What AquariumHQ has recorded, by jurisdiction, with the instrument each entry comes from and how far the check went. Ecological risk and legal status are separate: a species can be ecologically risky and legally unrestricted, or restricted where it could never establish.

EU

Not verified by AquariumHQpossession

No restriction was identified in the sources AquariumHQ checked for the EU as of 2026-08-11. That is not a finding that keeping, selling or moving this species is lawful there: sub-national rules, permit regimes and trade-specific requirements exist that these sources do not cover, and lists are amended. Check with the relevant authority before acquiring, selling or moving any animal.

Instrument recorded, species entry not re-checked · last checked 2026-08-11 · AquariumHQ has recorded the instrument and what it does, but has not re-confirmed this species' entry against the current consolidated text. Listings are amended, so treat this as a pointer to the right law rather than as a confirmation of the current position, and check with the authority before acting.

GB

Not verified by AquariumHQpossession

No restriction was identified in the sources AquariumHQ checked for Great Britain as of 2026-08-11. That is not a finding that keeping, selling or moving this species is lawful there: sub-national rules, permit regimes and trade-specific requirements exist that these sources do not cover, and lists are amended. Check with the relevant authority before acquiring, selling or moving any animal.

US

Not verified by AquariumHQpossession

No restriction was identified in the sources AquariumHQ checked for the United States at federal level as of 2026-08-11. That is not a finding that keeping, selling or moving this species is lawful there: sub-national rules, permit regimes and trade-specific requirements exist that these sources do not cover, and lists are amended. Check with the relevant authority before acquiring, selling or moving any animal.

Never release aquarium life into the wild

Aquarium animals, plants, and aquarium water must never be released into ponds, rivers, canals, drains or the sea — not even in a country where the species is sold freely. Released fish and invertebrates establish populations that displace native species, and released plants and water carry pathogens, parasites and fragments capable of spreading without any animal at all. If you can no longer keep an animal, rehome it through an aquarium society, a retailer that accepts returns, or another keeper.

Rehome through a local aquarium society, a specialist retailer or another keeper.
Unwanted plants go in household waste or a hot compost heap, never in a watercourse or a garden pond.
Never empty a bucket of tank water into a drain that discharges to open water.
If an animal is beyond rehoming, ask an aquatic veterinarian about humane euthanasia rather than releasing it.

Legal status is recorded from the sources named and was correct on the verification date shown. Rules change, and sub-national rules often differ from national ones. Check the current position with the relevant authority before acquiring, selling or moving any animal or plant.

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	Sahyadria denisonii	Observed / measured	high confidence	Catalogue of Life; GBIF — Global Biodiversity Information Facility
native range	Western Ghats rivers, Kerala and Karnataka, India	Observed / measured	moderate confidence	GBIF — Global Biodiversity Information Facility
adult size	11–15 cm	Aquarium-literature consensus	moderate confidence	AquariumHQ husbandry synthesis
lifespan	5–8 years	Aquarium-literature consensus	moderate confidence	AquariumHQ husbandry synthesis
temperature	18–25 °C	Aquarium-literature consensus	moderate confidence	AquariumHQ husbandry synthesis
ph	6.5–7.8 pH	Aquarium-literature consensus	moderate confidence	AquariumHQ husbandry synthesis
general hardness	3–15 °dGH	Aquarium-literature consensus	moderate confidence	AquariumHQ husbandry synthesis
minimum tank volume	≥ 350 L	AquariumHQ editorial position	moderate confidence	AquariumHQ husbandry synthesis
minimum tank length	≥ 150 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 2026-08-12. One authoritative backbone is what this class requires.