All fish / Chaetodontidae

Eastern triangle butterflyfish

Chaetodon baronessa

Also known as triangle butterflyfish, baroness butterflyfish, triangular butterflyfish, eastern triangular butterflyfish, baronessa butterfly, ミスジチョウチョウウオ, kepe-kepe segitiga, 曲纹蝴蝶鱼, 三角蝴蝶鱼

A deep, roughly triangular butterflyfish with a pattern of chevron-like purplish brown and cream lines, a yellow-edged rear and dark bars through the eye. It is admired for its unusual shape and subtle colours, but its specialised diet makes it a fish for experts only.

Care at a glance

Care level

Hard

Temperament

Peaceful

Adult size

14 cm

Temperature

24 to 28 °C

pH

8.1 to 8.4

Smallest tank

400 litres

Keep as

Singly or as a mated pair

Diet

Carnivore: obligate coral polyp feeder (mainly Acropora); rarely weans onto mysis or other frozen foods

Swims

Middle of the tank

Lifespan

5 to 10 years

Water

Marine (saltwater)

Wild range

Eastern Indian Ocean and western Pacific: Indonesia, Philippines, Great Barrier Reef to Fiji and Japan

Breeding

It spawns as pairs releasing eggs into open water, and the larvae go through a long planktonic stage. It has not been bred in home aquariums.

Good to know

It feeds almost entirely on live Acropora and other stony corals, so most specimens starve in captivity and it will destroy a reef tank; it is best left in the wild. Do not confuse with the Indian Ocean triangle butterflyfish, Chaetodon triangulum.