Red-tailed Black Shark

The Red-tailed Black Shark (Epalzeorhynchos bicolor) is one of the most visually striking freshwater fish in the aquarium hobby, famed for its jet-black body and vivid crimson tail. Despite its name and shark-like profile, it is actually a member of the carp family (Cyprinidae) and completely unrelated to real sharks. While it is critically endangered in its native waters of Thailand due to habitat loss, captive-bred specimens thrive worldwide in home aquariums.

Aquarium Care Overview

Red-tailed Black Sharks are energetic, bottom-dwelling swimmers. However, they possess a semi-aggressive and highly territorial temperament that requires careful planning.

Parameter	Recommended Level
Minimum Tank Size	55 gallons (4-foot length minimum)
Water Temperature	72°F to 80°F (22°C to 27°C)
pH Range	6.5 to 7.5
Water Hardness	Soft to medium (up to 15 GH)
Lifespan	5 to 8 years (sometimes up to 10)
Adult Size	5 to 6 inches (15 cm)

Behavior & Tank Mates

Strictly Solo: You should keep only one Red-tailed Black Shark per tank. They are fiercely hostile toward their own kind and other shark-like fish (such as Rainbow Sharks or Silver Sharks).
Territorial Maturity: As juveniles, they are relatively peaceful, but they become highly protective of their territory as they grow.
Ideal Tank Mates: Choose fast-moving, robust fish that occupy the upper zones of the aquarium, such as Danios, Barbs, Gouramis, and larger tetras.
Species to Avoid: Do not house them with slow-moving or long-finned species (like Angelfish or Guppies) that can be easily bullied.

🌿 Habitat Setup

To keep aggression low, break up sightlines across the bottom of the tank so your shark can claim a specific domain:

Hiding Places: Provide plenty of caves, large smooth stones, and driftwood to build safe hiding zones.
Substrate: A sandy or fine-gravel bottom prevents them from scratching their delicate sensory barbels while foraging.
Plants & Flow: Use hardy live plants like Anubias alongside strong filtration to replicate their native fast-flowing rivers.
Diet & Feeding
These fish are non-fussy omnivores that actively forage across the tank floor:
- Sinking Pellets & Flakes: High-quality sinking catfish pellets or algae wafers should form their daily staple.
- Protein Boosts: Supplement their diet with frozen or live foods like bloodworms, brine shrimp, and daphnia.
- Fresh Greens: They love grazing on fresh, blanched vegetables like zucchini, cucumber, or spinach once a week.