Red Tail Shark

The Red Tail Shark is an iconic freshwater aquarium fish featuring a velvety black body with a brilliant red tail fin. Native to Thailand, these fish are now extinct in the wild but thrive in aquariums worldwide. They are territorial bottom-dwellers that require their own cave or hiding spot and will fiercely defend it. Only one Red Tail Shark should be kept per tank unless the aquarium is very large (100+ gallons) with multiple territories. They are active algae eaters and bring striking contrast to planted tanks.

Care Requirements

Tank Setup

Red Tail Sharks need territories with caves or hiding spots.

Essential Setup:

• 30+ gallons minimum
• Caves, PVC pipes, driftwood
• Plants (may uproot tender plants)
• Moderate to strong filtration
• One territory per shark

Water Quality

• Temperature: 72-79°F (22-26°C)
• pH: 6.5-7.5
• Water Hardness: Moderate (5-15 dGH)
• Ammonia/Nitrite: 0 ppm
• Nitrate: <20 ppm

Feeding

Primarily herbivorous with algae preference:

• Algae wafers (daily)
• Spirulina flakes
• Vegetables: blanched zucchini, cucumber
• Occasional protein foods

Behavior & Compatibility

Territorial bottom-dweller:

• Claims territory: Usually a cave or hiding spot
• Defensive: Chases fish from territory
• Active: Constantly grazing on algae
• Aggression: Mainly toward similar-looking fish

Compatible With:

• Fast mid-to-upper level fish
• Robust community fish
• Medium cichlids

Never Keep With:

• Other Red Tail Sharks
• Rainbow Sharks
• Corydoras (may bully)
• Slow bottom dwellers

Conservation Note

• Critically Endangered: Extinct in the wild (IUCN)
• Cause: Habitat destruction in Thailand
• Aquarium population: All specimens captive-bred
• Importance: Support captive breeding programs

Color Enhancement

• Excellent water quality brings out best red
• Dark substrate enhances black body
• Varied diet maintains color
• Stress reduces red coloration

Breeding

Not bred in home aquariums:

• Commercial breeding operations
• Difficult to sex
• Egg scatterers