Blue Tang

Looks how to spot one

Scaled, oval surgeonfish

An oval, flattened fish in rich royal blue, with a bold black pattern along the upper body that loops round to leave a blue patch on each side, a bit like an artist's palette. The tail is bright yellow in a triangle shape, and the pectoral fins are tipped yellow too. Young fish start out mostly yellow with blue near the eyes. A small, sharp spine sits on each side of the tail base. The blue becomes paler at night.24

Personality what they are like

Energetic and a bit shy at first. It likes to have a crevice or branching coral it can dash into when startled, and young fish in particular hide quickly. Males can be competitive with each other, circling and showing off their tail spines, so they do best with peaceful, non-look-alike company.43

Daily activity how busy a day looks

A strong, daytime swimmer that in the wild lives on clear outer reef slopes with moderate to strong current. It enjoys long open stretches to swim plus good water movement.12

Grooming and care the hands-on bits

Marine reef fish for an established saltwater aquarium. Typical reef-tank conditions are 24-27 C, salinity 1.022-1.025 specific gravity and pH around 8.2. Feed a varied diet several times a day, keep water stable, and provide strong water flow. Its tail spines are sharp, so move it with a container rather than bare hands. Nearly all blue tangs sold are still wild-caught, so choosing captive-bred fish when available supports wild reefs.5432

Home where they are happiest

Lives near the bottom on current-swept terraces of seaward reefs at about 2 to 40 m, using branching coral as cover. At home it needs a large, long marine tank with plenty of swimming space, solid rockwork with hiding places and strong flow. No minimum tank volume from a primary source was found.124

Food basics what goes in the bowl

An omnivore. Young fish eat mostly plankton, while adults feed on zooplankton and graze filamentous algae and microalgae from rocks and coral. A mix of marine algae and small meaty foods covers both sides.124

Company who they like around

Lives in pairs or loose groups of roughly 8 to 14 fish, and juveniles school near coral heads. Males can be rivals, so in home tanks one fish or a carefully planned group in a very large tank is usual.213

The story where it all began

Carl Linnaeus named the species in 1766, and it remains the only member of its genus. It has long been a favourite of marine aquarists and ranks among the most traded aquarium fish worldwide, with an estimated 95,000 imported in 2011, almost all collected from the wild. Fame came in 2003 when Dory, the forgetful and cheerful blue tang in Finding Nemo, made it one of the best known fish on the planet, followed by Finding Dory in 2016. Research later found that online interest jumped after the second film but imports did not rise noticeably. In 2016 biologist Kevin Barden of Rising Tide Conservation, working with the University of Florida, raised blue tangs in captivity for the first time after about six years of effort, a step towards farmed fish for the hobby.21

Recognised by the official bits

IUCN Red List

Least Concern (assessed 7 May 2010)1

Taxonomy

Only species in the genus Paracanthurus, family Acanthuridae; described by Linnaeus in 1766. Its closest relatives are the Zebrasoma tangs.2

Popularity Ranked the 8th most traded aquarium fish species worldwide; about 95,000 imported in 2011.