Blue Hippo Tang

Paracanthurus hepatus

Also known as Blue Tang, Regal Tang, Pacific Blue Tang, Palette Surgeonfish, Hippo Tang

SaltwaterFish

Blue Hippo Tang (Paracanthurus hepatus) — DerHans04 · CC BY-SA 3.0

Care at a glance

Temperature: 73–81°F (23–27°C)
pH: 8.1–8.4
Adult size: 11.8 in (30 cm)
Minimum tank: 180 gal (680 L)
Temperament: Mostly peaceful
Social behavior: Social
Swim level: Middle
Difficulty: Difficult
Breeding: Hard
Rarity: Common
Reef safe: Reef safe
Origin: Indo-Pacific, from East Africa and the Red Sea across to the central Pacific including the Great Barrier Reef
Family: Acanthuridae

Overview

A large, fast, open-water swimmer that is reef safe because it ignores corals and inverts when kept well fed on algae and meaty foods. It is generally peaceful toward other fish, but it can squabble with its own kind and other tangs in tight quarters, so give it room and add it with care. Its real challenge is health rather than aggression: it stresses badly during shipping and is one of the most ich-prone fish in the hobby, so a proper quarantine and a stable, low-stress tank are essential. When frightened it can play dead by lying on its side, and the tail spine is sharp.

In the wild

Found on clear seaward reefs where there is current, usually in loose groups that hover above staghorn coral and dart into the branches when threatened. Juveniles stay close to a single coral head while adults range more widely to feed on plankton and algae in the water column and off the rock. In the aquarium it needs a long tank with strong flow, high oxygen, open swimming lanes, and rockwork with crevices it can wedge into when startled.

Good to know

Paracanthurus hepatus is the only species in its genus and carries the same folding tail spine as other surgeonfish. Unlike the strictly herbivorous tangs it feeds heavily on zooplankton in the wild, so it is both a grazer and a planktivore. It has been bred in captivity and captive-bred juveniles are now sold, but the larvae are difficult to raise so most stock is still wild caught. Adults can reach about 30 cm.

Did you know

When alarmed it will wedge into a rock crevice and lock itself in place with its spines, and it sometimes lies motionless on its side as if dead to avoid predators.