TankBud

One species · 1 variety

Rainbow shark

Epalzeorhynchos frenatum

FreshwaterFish

Rainbow shark (Epalzeorhynchos frenatum)
MerlinSenger at German Wikipedia · CC BY-SA 3.0

Care at a glance

Temperature
68–79°F
20–26°C
pH
6.5–7.5
Adult size
5.9 in
15 cm
Minimum tank
63 gal
240 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, Laos, Cambodia

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One setup covers every line on this page: care is the species' care.

Overview

The rainbow shark is a territorial bottom dweller that needs a roomy tank and tank mates chosen with caution. It suits a keeper past the beginner stage.

Did you know

Rainbow sharks get more aggressive as they mature. They are especially rough on anything that resembles them, including red-tailed sharks and other rainbow sharks.

Caring for the rainbow shark

Give a rainbow shark a roomy tank of at least 63 gal (240 L), with a sand or smooth gravel bottom. Add caves, rocks and wood for it to claim as territory, and break up clear sight lines with decor. Hiding spots matter, since this fish wants a base to defend.

Keep the water at 68 to 79°F (20 to 26°C) and a pH of 6.5 to 7.5. It eats algae, sinking pellets and frozen foods.

Keep one per tank, since it is solitary and territorial toward its own kind and similar-looking fish. It lives on the bottom, so house it with active fish of the middle and upper levels that it can largely ignore. Avoid other bottom dwellers, which it will harass.

Rainbow sharks are rarely recorded breeding in home aquariums. Most in the trade are raised commercially with hormones.

Good to know

The rainbow shark is a member of the Cyprinidae, the carp and minnow family, and not a true shark. It is named for its tall, sail-like dorsal fin. The wild population has declined, though aquarium stock is plentiful.

In the wild

Rainbow sharks come from rivers and streams in Thailand, Laos and Cambodia. They graze biofilm and algae off the bottom there and patrol a patch of riverbed.

From published sources

Tank mates

Each fish here is named as a tank mate for the rainbow shark by at least two published care guides. Keep one rainbow shark per tank, add it last, and choose tank mates that swim above the bottom.

Sources: Seriously Fish, Aquarium Source, Fishkeeping World, Imperial Tropicals.

Check the full mix in the stocking calculator

Common questions

What size tank does a rainbow shark need?

A rainbow shark needs at least 63 gal (240 L). It spends most of its time in the bottom.

What temperature and pH does a rainbow shark need?

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

What does a rainbow shark eat?

A rainbow shark eats algae, along with sinking pellets and frozen foods.

How big does a rainbow shark get?

An adult rainbow shark reaches about 5.9 in (15 cm).

How does a rainbow shark breed?

Rainbow sharks are rarely recorded breeding in home aquariums. Most of those in the trade are raised commercially with the help of hormones.

What fish can live with the rainbow shark?

Published care guides name tiger barb, cherry barb, neon rainbowfish and zebra danio, among others. Keep one rainbow shark per tank, add it last, and choose tank mates that swim above the bottom.

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