Thai National Parks

Species of Thailand

Eastern triangle butterflyfish

Chaetodon baronessa

Georges-Frédéric Cuvier, 1829

:Not to be confused with the Triangle Butterflyfish (C. triangulum) and the Triangulate Butterflyfish (C. trifascialis).

The Eastern Triangle Butterflyfish, Chaetodon baronessa, is a species of butterflyfish (family Chaetodontidae). It is found in the central Indo-West Pacific region from the Cocos-Keeling Islands and Indonesia in the eastern Indian Ocean to Fiji and Tonga, north to southern Japan, south to New Caledonia and New South Wales in Australia.

It grows to a maximum of 16 cm long. The body has a pattern of alternating cream and grey-brown to purple chevron-shaped bars. There are three dark bars on the head, including one running across the eye.

The Triangle Butterflyfish (C. triangulum) is its western sister species, replacing C. baronessa in the Indian Ocean. The triangle butterflyfishes and the Hooded Butterflyfish (C. larvatus) form the subgenus Gonochaetodon. If Chaetodon is split up as some researchers propose, this group might go into Megaprotodon as other high-backed and square-bodied species, but its exact relationships are still not well known.

The Eastern Triangle Butterflyfish is found in seaward and lagoon coral reefs. They usually swim around in pairs and are territorial. This species feeds exclusively on the polyps of the tubular Acropora corals.

This article uses material from Wikipedia released under the Creative Commons Attribution-Share-Alike Licence 3.0. Eventual photos shown in this page may or may not be from Wikipedia, please see the license details for photos in photo by-lines.

Scientific classification

Chaetodon baronessa

Common names

  • English:
    • Eastern triangle butterflyfish
    • Eastern triangular butterflyfish
    • Pacific triangular butterflyfish
    • Triangular butterflyfish


  • Chaetodon barronessa, Georges-Frédéric Cuvier (1829)

Conservation status

Least Concern (IUCN3.1)

Least Concern (IUCN3.1)


Please help us review our species pages if wrong photos are used or any other details in the page is wrong. We can be reached via our contact us page.

Chaetodon baronessa

Range Map