Redtail Shark

A jet-black, red-tailed cyprinid that patrols the bottom like a shark. Strictly one per tank — they relentlessly chase their own kind — and bottom-level tank mates need the space to stay clear of it.

• Minimum footprint: 40 gallons; a 55+ gallon tank gives real swimming room.
• Preferred swimming zone: bottom of the water column.
• Happy alone or as a compatible pair; avoid crowding with conspecifics.
• Care level: moderate.

• Temperature: 72–79°F
• pH: 6.5–7.5
• Hardness: 5–15 dGH (Moderate)

Stable parameters matter more than perfect ones — aim for consistency before chasing an exact number.

semi-aggressive

bottom-dwellerterritorialsolitaryactivealgae-grazer

An omnivore — offer a staple flake or pellet plus regular frozen or live foods (daphnia, bloodworm, brine shrimp) and some vegetable matter for balance.

No outright-compatible species in our current database — check individual pairings with the compatibility tool.

• Neon Tetra — Occasional chasing or fin nipping is possible.
• Glowlight Tetra — Occasional chasing or fin nipping is possible.
• Ember Tetra — Occasional chasing or fin nipping is possible.
• Serpae Tetra — Occasional chasing or fin nipping is possible.
• Celestial Pearl Danio — Occasional chasing or fin nipping is possible.
• Cherry Shrimp — Occasional chasing or fin nipping is possible.

Standard tanks at or above the recommended 55 gallons:

• 55 gallon 48 × 13 × 21″
• 75 gallon 48 × 18 × 21″
• 90 gallon 48 × 18 × 25″
• All tank sizes

• Start from a 40 gallon minimum and plan the full group size before you buy.
• Activity level is high, which affects how much of the tank it uses and how much it adds to the bioload.
• Zoning matters: this species lives mostly in the bottom zone, so choose tank mates that occupy other levels.

Compatibility depends on tank size, water chemistry, temperament, and adult size. Run a full check against any species in our database.

• FishBase(Scientific Database, accessed 2026-09-20)
• SeriouslyFish(Specialist Publication, accessed 2026-09-20)
• Practical Fishkeeping(Specialist Publication, accessed 2026-09-20)
• Aquarium Forge editorial guidelines(Editorial Interpretation, accessed 2026-09-22)

Data reviewed: September 2026 · Data version: 2026.11
Editorial note: Minimum tank recommendations may vary by source and husbandry approach. Our figures synthesise the sources above for planning purposes.