Roseline Shark

The Roseline Shark, also known as the Denison Barb or Red Line Torpedo Barb, is one of the most striking freshwater aquarium fish. Featuring a brilliant red line running from nose to tail with a contrasting black line below, these active swimmers are native to fast-flowing streams in India. They are peaceful but require space to swim and should be kept in schools of 6 or more. Due to overcollection in the wild, most specimens are now captive-bred.

Care Requirements

Tank Setup

Roseline Sharks need long tanks with strong flow and open swimming space.

Essential Setup:

• 55+ gallons minimum (4-foot length)
• Strong filtration/current
• Open swimming lanes
• Some plants for security
• Cooler water preferred

Water Quality

• Temperature: 60-77°F (15-25°C) - cooler than most tropical fish
• pH: 6.8-7.8
• Water Hardness: Moderate (5-15 dGH)
• Ammonia/Nitrite: 0 ppm
• Nitrate: <20 ppm

These fish prefer cooler, well-oxygenated water with good flow.

Feeding

Omnivores that need variety:

• High-quality flakes or pellets
• Frozen foods: bloodworms, brine shrimp
• Vegetables: blanched spinach, peas
• Algae wafers

Behavior & Compatibility

Very active, peaceful schooling fish:

• School size: 6+ minimum, 10+ ideal
• Active swimmers: Constant movement
• Peaceful: Good with similar-sized fish
• Jumpers: Secure lid required

Good Tank Mates:

• Giant Danios
• Rainbowfish
• Larger tetras
• Fast-moving community fish

Conservation Note

• Wild populations threatened by overcollection
• Buy captive-bred specimens
• More expensive due to breeding challenges
• Support sustainable aquarium trade

Breeding

Very difficult to breed in captivity:

• Most available fish are wild-caught or pond-raised
• Requires specific water parameters
• Large, mature specimens needed
• Commercial breeding improving