How big does Red-tailed Shark get?

Red-tailed Shark reaches an adult standard length of 12–15 cm (excluding the caudal fin). Size the tank for that, not for the juvenile you bring home — the difference is often several times over, and upgrading later costs more than buying once.

What water does Red-tailed Shark need?

22–28 °C, pH 6.5–7.5, 2–15 dGH. At 6 °C wide it is one of the more forgiving ranges.

What is the smallest tank for Red-tailed Shark?

At least 100 L, and no shorter than 80 cm. That is the floor for long-term keeping, not for short-term survival: volume buys water stability and length buys swimming room, and neither substitutes for the other. It is not a schooling fish, so a single specimen or a pair is fine.

What is Red-tailed Shark like to keep?

Temperament: aggressive. Difficulty: beginner. It occupies the bottom and is omnivore. With plants it is "Leaves plants alone".

Can Red-tailed Shark be kept with its most common tank mate?

The checker returns "Not recommended together". Red-tailed Shark and Flying Fox is a recorded conflict in this atlas. Predation, territorial fighting or conspecific aggression is the usual outcome, and a bigger tank does not change it.

G-01 / 41Freshwater

Red-tailed Shark红尾黑鲨

Epalzeorhynchos bicolor · Cyprinidae

Jet black with a single red tail and deeply territorial: two in a tank fight until one remains.

Illustration to come

G-01 / 41 · Red-tailed Shark Epalzeorhynchos bicolor

SpecificationsFish atlas

Name: 红尾黑鲨
Scientific name: Epalzeorhynchos bicolor
Family: Cyprinidae
Origin: Chao Phraya basin, Thailand
Adult size: 12–15 cm
Temperament: Aggressive
Diet: Omnivore
Water level: Bottom
Level: Beginner
Min. tank: 100 L
Min. length: 80 cm
Plant safe: Leaves plants alone

Water requirementsFreshwater

Temp.22–28 °C

pH6.5–7.5

Hardness2–15 dGH

Units: temperature in °C, hardness in German degrees (dGH / dKH), marine salinity as specific gravity at 25 °C, volume in litres. These are the values recorded for the species and do not follow the site unit switcher.

Keeping notes

1Extremely territorial: two in a tank fight until one remains, so keep a single fish.
2Harasses flying foxes, Crossocheilus and bottom dwellers, so choose fast mid-water tankmates.
3Reaches 15 cm; use a tank at least 80 cm long with wood caves as territory.
4Juveniles are brightest and adults darken with age, which is normal rather than illness.
5Omnivorous on wafers and pellets in neutral to slightly hard water at 22-28 °C.

Check a tank mate

Jump straight to the verdict for Red-tailed Shark against this one — no need to pick it again.

Frequently asked questions

How big does Red-tailed Shark get?: Red-tailed Shark reaches an adult standard length of 12–15 cm (excluding the caudal fin). Size the tank for that, not for the juvenile you bring home — the difference is often several times over, and upgrading later costs more than buying once.
What water does Red-tailed Shark need?: 22–28 °C, pH 6.5–7.5, 2–15 dGH. At 6 °C wide it is one of the more forgiving ranges.
What is the smallest tank for Red-tailed Shark?: At least 100 L, and no shorter than 80 cm. That is the floor for long-term keeping, not for short-term survival: volume buys water stability and length buys swimming room, and neither substitutes for the other. It is not a schooling fish, so a single specimen or a pair is fine.
What is Red-tailed Shark like to keep?: Temperament: aggressive. Difficulty: beginner. It occupies the bottom and is omnivore. With plants it is "Leaves plants alone".
Can Red-tailed Shark be kept with its most common tank mate?: The checker returns "Not recommended together". Red-tailed Shark and Flying Fox is a recorded conflict in this atlas. Predation, territorial fighting or conspecific aggression is the usual outcome, and a bigger tank does not change it.