Roseline Shark (Sahyadria denisonii)

Roseline Shark — Sahyadria denisonii

High-speed elegance with razor contrast

The Roseline Shark, also known as the Denison Barb, is one of the most recognizable river fish in the hobby. A sleek silver body is sliced by a bold black lateral stripe and topped with a vivid red streak that runs from the snout through the eye. The dorsal fin often carries red accents as well, and the forked tail may show yellow and black highlights. When kept in proper groups, the red intensifies and flashes dramatically as the school turns in unison.

Native to fast-flowing rivers of the Western Ghats in India, Sahyadria denisonii is built for constant motion. Its torpedo-shaped body and powerful tail make it an endurance swimmer that thrives in well-oxygenated water with steady current. Unlike true sharks, this species is a cyprinid barb, but its speed and streamlined profile give it that “shark-like” presence.

Growing to 5–6 inches, Roseline Sharks are peaceful yet energetic, making them perfect for large, active community or river-style aquariums.

Aquarium Setup

• Minimum Tank Size: 75 gallons (125+ gallons recommended for larger schools)

• Group Size: 6 or more strongly recommended

• Substrate: Sand, fine gravel, or river rock

• Flow: Moderate to strong current preferred

• Décor: Open swimming lanes with rock and wood structure along edges

• Lighting: Moderate to bright (enhances red stripe contrast)

• Filtration: Strong biological filtration required

• Oxygen: High dissolved oxygen essential

Tank Mates

Best with peaceful to semi-assertive species:

• Rainbowfish

• Larger tetras

• Loaches

• Peaceful cichlids

• Non-aggressive catfish

Avoid aggressive predators and fin-nipping species.

Water Parameters

• Temperature: 68–75°F (20–24°C)

• pH: 6.5–7.5

• Hardness: Soft to medium

• Water Quality: Clean, stable, and highly oxygenated

Diet

Omnivorous:

• High-quality pellets or flakes

• Frozen brine shrimp and bloodworms

• Small insects

• Occasional vegetable matter