Eastern Triangle Butterflyfish

Chaetodon baronessa

Fish
IUCN: Least concern

Usual depth5–10 m
Water temperature23–30 °C
Best monthsJune, September, and October
How commonOccasional

Photo credit: (c) Bernard DUPONT, some rights reserved (CC BY) · CC BY · iNaturalist

About this species

The eastern triangle butterflyfish, also known as the baroness butterflyfish, is a species of marine ray-finned fish, a butterflyfish belonging to the 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.

Text from the Wikipedia article “Eastern triangle butterflyfish”, licensed CC BY-SA 4.0. Read the article

Where and when

Where it has been recorded

Worldwide

Loading the map

Best months

Worldwide (open data)

January: 171 records
February: 114 records
March: 206 records
April: 194 records
May: 208 records
June: 295 records
July: 208 records
August: 165 records
September: 255 records
October: 340 records
November: 212 records
December: 164 records

Depth and water temperature

Depth

Mostly recorded at 5–10 m · Deepest record: 747 m

0–10 m: 559 records
10–20 m: 140 records
20–30 m: 3 records
30–40 m: 0 records
40–50 m: 0 records
50–60 m: 0 records
60–70 m: 0 records
70–80 m: 0 records
80–90 m: 0 records
90–100 m: 0 records
100–110 m: 0 records
110+ m: 3 records

Water temperature

Recorded in surface water of 23–30 °C

22–24 °C: 1 records
24–26 °C: 5 records
26–28 °C: 95 records
28–30 °C: 73 records

Photos

(c) Debra Baker, some rights reserved (CC BY) · CC BY · iNaturalist
no rights reserved · CC0 1.0 · iNaturalist
(c) Ditch Townsend, some rights reserved (CC BY-SA) · CC BY-SA · iNaturalist
(c) Jan Ebr & Ivana Ebrová, some rights reserved (CC BY) · CC BY · iNaturalist
no rights reserved · CC0 1.0 · iNaturalist
(c) Ben Costamagna, some rights reserved (CC BY) · CC BY · iNaturalist
(c) Zara, some rights reserved (CC BY) · CC BY · iNaturalist

Names and classification

English: Eastern Triangle Butterflyfish, Eastern Triangular Butterflyfish, Pacific Triangular Butterflyfish, Triangular Butterflyfish

Names in 2 more languages

Japanese: Mikadochochouo, Mikado-chochô-uo, ミカドチョウチョウウオ
Simplified Chinese: 三角紋蝶, 天王蝶, 天皇蝶, 曲紋蝴蝶魚

Other scientific names: Chaetodon barronessa

Similar species

Sunburst butterflyfish
Chaetodon kleinii
Vagabond butterflyfish
Chaetodon vagabundus
Forcepsfish
Forcipiger flavissimus
Horned Bannerfish
Heniochus varius

Sources and credits

Names and taxonomy: WoRMS (CC BY 4.0) and the GBIF Backbone (CC BY 4.0). Photos: iNaturalist observers, each under the licence shown (CC0, CC BY or CC BY-SA).

Depth, temperature, months and maps: records from OBIS and GBIF under CC0 or CC BY.
Descriptions: Wikipedia, licensed CC BY-SA, each linked to its article.
Conservation status as published by GBIF (IUCN Red List).
1,748 open-data records from 1921 to 2023.
Species data updated October 26, 2026.

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