Denison Barb
Sahyadria denisonii
Also known as: Roseline shark, Red-line torpedo barb, Denisonii barb
Quick Facts
- Adult size: 11-15 cm (4.3-5.9 inches)
- Minimum tank size: 200 litres (53 gallons)
- Lifespan: 5–8 years
- Temperament: peaceful
- Swimming level: middle
- Diet: omnivore
- Minimum group size: 6
- Difficulty: intermediate
Water Parameters
- Temperature: 18–25°C
- pH: 6.5–7.8
- Hardness (GH): 89–268 ppm (5–15 dGH)
Values above are general hardness (GH). For carbonate hardness (KH), the buffer that keeps pH stable, see the water parameters guide.
Care Summary
A spectacular and now-ubiquitous showpiece: a sleek, silver, torpedo-shaped barb streaked with a bold red and black line down the body and a flash of yellow and red in the tail, sold under the marketing name roseline shark. Denison barbs are active, peaceful schooling fish that demand both numbers and space, plus the cool, fast, oxygen-rich water of their native Western Ghats streams; kept too warm, too crowded, or in too small a group they fade and weaken. Worth knowing: the species was so heavily collected for the aquarium trade after its discovery that wild populations crashed and it is now classed as endangered, so seek out the farmed fish that today make up most of the supply. Given a large, cool, well-circulated tank and a proper shoal, few community fish are more striking.
Tankmates
A fast, active, peaceful schooling fish that must be kept in a group of at least six, ideally more, in a long tank with strong flow and high oxygen, conditions that reflect its origin in the cool, fast hill streams of southern India. Peaceful toward similarly-sized fish but boisterous and quick enough to stress timid or slow tankmates and to outcompete or eat nano species and shrimp, so it suits a community of robust, active fish: rainbowfish, larger barbs, clown loaches, and silver dollars. Its preference for cooler water (it does poorly kept too warm long-term) is a key compatibility factor, ruling out warm-water species like discus. Sub-adults school tightly; lone or paired fish are nervous and prone to jumping.
Compatible with
- Boeseman's Rainbowfish
- Congo Tetra
- Tiger Barb
- Clown Loach
- Bristlenose Pleco
- Silver Dollar
- Red Rainbowfish
- Red-Tailed Black Shark
Avoid keeping with
Common Problems
- stress and faded colour in groups smaller than 6
- poor health when kept too warm long-term
- jumping from open tanks
- predation on small tankmates and shrimp
Sources: seriouslyfish.com, fishbase.org · Last updated: 2026-06-20