Red-Tailed Black Shark: Tank Size, Tank Mates and How Many to Keep

The red-tailed black shark is jet black with a scarlet tail. It is striking and territorial, and it wants the tank floor to itself.

Adult size
5.9 in15 cm
Smallest tank
55 gallons208 liters
How many
One only
Temperature
72–81 °F22–27 °C
pH
6.5–7.8
Temperament
Aggressive
Swims
On the bottom
Heater needed
Yes

What size tank does a red-tailed black shark need?

At least 55 gallons (208 liters). The smallest standard tank that works is the 55 gallon. A bigger tank is always easier to keep stable. We give the size for an adult fish, because the small fish in the shop will grow. Scientific name: Epalzeorhynchos bicolor.

How many red-tailed black sharks in each tank size?

This is how many each standard tank carries comfortably if red-tailed black sharks are the only fish in it. Share the tank with other species and the number goes down.

Keep one red-tailed black shark per tank, whatever the size. Of the common sizes, these are big enough: 55 gallon, 75 gallon, 125 gallon.

Check red-tailed black sharks against your own tank and other fish

Good to know

  • Keep one per tank. Two will fight over the floor.

Tank mates for red-tailed black sharks

These animals like the same water, are a safe size, and have a temper that fits. It is a match on paper: always watch new tankmates for the first week.

Poor matches

  • Betta: Red-tailed black shark is aggressive and much bigger. Betta would be bullied.
  • Fancy goldfish: Goldfish do best with other fancy goldfish.

Questions and answers

What size tank does a red-tailed black shark need?

At least 55 gallons (208 liters). The smallest standard tank that works is the 55 gallon. A bigger tank is always easier to keep stable.

How many red-tailed black sharks should be kept together?

Just one. Red-tailed black shark adults fight each other in a home tank.

Can red-tailed black sharks live in a 10 gallon tank?

No. Red-tailed black shark needs at least 55 gallons (208 liters), and grows to 6 in (15 cm), far too long for a 20 inch tank.

What temperature do red-tailed black sharks need?

72–81 °F (22–27 °C), with a pH of 6.5–7.8. In most homes that means a heater.

Can red-tailed black sharks live with a betta?

It is not a good match. Red-tailed black shark is aggressive and much bigger. Betta would be bullied.

More fish

Adult size, tank size and water ranges follow the mainstream care consensus (Seriously Fish species profiles and FishBase maximum lengths). Where sources differ we use the more cautious figure. Stocking numbers come from our stocking calculator.