TankBud

Red-tailed black shark

Epalzeorhynchos bicolor

FreshwaterFish

Red-tailed black shark (Epalzeorhynchos bicolor)
Astellar87 · CC BY-SA 4.0

Care at a glance

Temperature
68–79°F
20–26°C
pH
6.5–7.5
Adult size
4.7 in
12 cm
Minimum tank
30 gal
115 L
Temperament
Mostly peaceful
Social behavior
Solitary
Own kind
One per tank
Tankmates
With caution
Swim level
Bottom
Difficulty
Medium
Breeding
No record
Rarity
Common
Family
Cyprinidae
Origin
Thailand

Overview

This is a solitary, territorial fish that holds the bottom and chases off its own kind and anything that looks similar, so keep just one per tank. It does best in a larger community with active mid and upper water fish that stay out of its zone, and plenty of hiding spots to break up its territory. Feed sinking pellets, algae wafers, and the occasional frozen treat like bloodworms or brine shrimp. Good oxygen and current keep it comfortable.

In the wild

Red-tailed black sharks come from the Chao Phraya basin in Thailand, living in clear, flowing rivers and streams over rock and sand with plants and roots for shelter. In the tank they like steady flow, good oxygen, and plenty of caves and wood to claim and hide in. Keep the pH from 6.5 to 7.5 and temps in the low to mid 20s C. Give them a 115 liter tank or larger with broken-up territory.

Good to know

This is a member of the carp family, Cyprinidae, reaching about 12 cm, with a jet-black body and a bright red tail. It is an egg-layer that rarely breeds in home tanks. The IUCN lists it as Critically Endangered in the wild because of habitat loss, so nearly every fish in the trade is commercially farmed rather than wild-caught.

Did you know

Once common in Thai rivers, it was feared extinct in the wild for years before small populations turned up again, and it remains Critically Endangered. The hobby owes its supply almost entirely to farms, mostly in Southeast Asia, a rare case of aquaculture keeping a species available while its native range stays in trouble.

Common questions

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

A Red-tailed black shark needs at least 30 gal (115 L). It spends most of its time in the bottom.

What temperature and pH does a Red-tailed black shark need?

A Red-tailed black shark is comfortable at 68–79°F (20–26°C) with a pH of 6.5–7.5.

How big does a Red-tailed black shark get?

An adult Red-tailed black shark reaches about 4.7 in (12 cm).

Related species