Denison barb - Sahyadria denisonii

Scientific name: Sahyadria denisonii

Common name: Denison barb

Family: Cyprinidae

Usual size in fish tanks: 12 - 15 cm (4.72 - 5.91 inch)

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Recommended pH range: 6.4 - 7.5

Recommended water hardness: 4 - 15°N (71.43 - 267.86ppm)

0°C 32°F30°C 86°F

Recommended temperature range: 20 - 26 °C (68 - 78.8°F)

The way how these fish reproduce: Spawning

Where the species comes from: South Asia

Temperament to its own species: peaceful

Temperament toward other fish species: peaceful

Usual place in the tank: Middle levels

General Information

The Denison barb (Sahyadria denisonii), also sold as the roseline shark or red line torpedo barb, is a fast-swimming shoaler endemic to the Western Ghats of southern India (Kerala and south Karnataka). In nature it inhabits clear, highly-oxygenated hill streams and upper river reaches with rock, boulders and riparian cover. Adult size is typically 12–15 cm (≈5–6″). Current taxonomy places the species in Sahyadria (ex-Puntius, Dawkinsia).

Food & Feeding

An omnivore that grazes and picks at invertebrates and biofilm. Use quality flakes or sinking micro-pellets as the staple; rotate frozen/live items (daphnia, brine shrimp, bloodworms in moderation) plus some plant matter (spirulina/algae wafers, blanched veg). Offer small portions 1–2× daily; they may nibble softer plants.

Sexing

External differences are subtle. Mature females are often fuller-bodied; males may show slightly stronger color. Venting is the most reliable method in adults.

Breeding

Egg-scattering spawner in nature. Home-aquarium spawnings are rare; most commercial production relies on hormone-induced breeding in farms. If attempting, use a long, well-oxygenated stream-style tank with cool end temperatures, strong current, and heavy plant/mop density; remove adults post-spawn.

Lifespan

Expect around 5–7 years with superb water quality and ample swimming space; longer is possible under optimal conditions.

Tank Requirements & Water Parameters

Group & space: keep in a shoal (≥6). Provide a long tank (min. 120 cm/4′; larger preferred) with open lanes for sustained swimming.
Flow & oxygen: emulate a fast, well-oxygenated stream (powerful filtration, added flow, high surface agitation). These fish decompensate in low-O₂, warm, stagnant water.
Water: pH ~6.4–7.5, hardness ~4–15 °dH; temperature 20–26 °C works well, with many keepers favoring the cooler/middle band for color and stamina.
Layout: rounded stones, wood, dense marginal planting or fake plants for cover; dark substrate and bright overhead light accent their stripe.
Maintenance: low nitrate, frequent water changes; tight lid (excellent jumpers).

Compatibility & Tank Mates

Peaceful, very active shoaler. Combine with similarly sized, fast, non-nippy fish (larger danios, barbs, rainbowfish, robust tetras). Avoid tiny tankmates that are easily outcompeted, and fin-dragging species that dislike current. Keep in numbers to diffuse skittishness.

Behaviour & Usual Place in the Tank

Middle water column (often ranging into upper levels), cruising against the current in open water and darting through rock lanes. Provide sight-line breaks to reduce chase behavior.

Conservation Note

S. denisonii is listed as Endangered on the IUCN Red List, primarily due to overharvest and habitat loss. Prefer captive-bred stock where available and avoid wild-caught juveniles from small, fragmented populations.

Short Description

Denison barb (Sahyadria denisonii) is a swift, shoaling Western Ghats cyprinid that needs cool-to-mild temperatures, high oxygen, strong current, and lots of room. Feed a varied omnivorous diet and keep in numbers; home breeding is uncommon and often replaced by hormone-induced commercial production.

Q&A

Puntius, Dawkinsia, or Sahyadria? Current genus is Sahyadria (Raghavan et al. 2013); Puntius/Dawkinsia appear in older sources and the trade.
Where exactly is it from? Fragmented populations in the Western Ghats (Kerala & south Karnataka) in clear, fast streams.
How big and how many? Plan for ~12–15 cm adults and a group of 6 in a long tank with strong flow.
Can I breed them? Rare at home; farms in India use induced spawning protocols.