Thompson's butterflyfish (Hemitaurichthys thompsoni)

Classification (WoRMS)

Full classification as recorded by WoRMS: Kingdom: Animalia · Phylum: Chordata · Class: Teleostei · Order: Acanthuriformes · Family: Chaetodontidae · Genus: Hemitaurichthys.

Accepted name: Hemitaurichthys thompsoni · Authority: Fowler, 1923 · Taxonomic status: accepted · AphiaID: 277576.

Source: World Register of Marine Species (WoRMS) — https://www.marinespecies.org/aphia.php?p=taxdetails&id=277576 (CC BY 4.0). Accessed 2026-09-23.

Biology and life history (FishBase)

Measured values published by FishBase for Hemitaurichthys thompsoni. Only fields the database actually holds for this species are shown; these are database values, not aquarium guidance.

Maximum length: 18 cm · Depth range: 4–300 m · Habitat zone: reef-associated · Body shape: short and / or deep · Vulnerability index: 10 of 100 · Fishery importance: commercial · Aquarium trade: commercial.

FishBase notes: Found in coral reefs (Ref. 43239). Occur in schools above steep outer reef slopes at depths below 10 m to 300 m and sometimes above clear lagoon reefs at depths as shallow as 4 m. Uncommon (Ref. 9710). Benthopelagic (Ref. 58302). Feeds on zooplanktons (Ref. 89972). Oviparous (Ref. 205). Form pairs during breeding (Ref. 205).

Source: FishBase species summary (SpecCode 5587) — https://www.fishbase.se/summary/Hemitaurichthys-thompsoni.html (CC BY-NC 3.0 — non-commercial use only). Accessed 2026-09-23.

Distribution and occurrence records (GBIF)

649 georeferenced occurrence records for Hemitaurichthys thompsoni are published through GBIF from 7 countries or marine areas. The map above plots 42 distinct locations from a sample of 649 records, omitting 6 inland records that carry an institution's coordinates rather than a collection site; it shows where the species has been observed and reported, not a modelled range.

Most records by country or area: American Samoa (253); United States Minor Outlying Islands (210); Northern Mariana Islands (96); United States of America (48); French Polynesia (39); Cook Islands (2); Japan (1).

Source: GBIF Occurrence Search (taxonKey 2385648) — https://www.gbif.org/occurrence/search?taxon_key=2385648&has_coordinate=true (records CC0 / CC BY); WoRMS distribution records (MarineRegions) — https://www.marinespecies.org/aphia.php?p=taxdetails&id=277576 (CC BY 4.0); Natural Earth 110m basemap — https://www.naturalearthdata.com/ (public domain). Accessed 2026-09-23.

Conservation status (IUCN Red List)

The IUCN Red List assesses Hemitaurichthys thompsoni Fowler, 1923 as Least Concern (code LC). No trend, population estimate or threat analysis is given here, because none is available from this source without the Red List API; follow the source link for the full assessment, including its date.

Source: IUCN Red List of Threatened Species (taxon 154788) — https://www.iucnredlist.org/species/154788/0; GBIF IUCN Red List category endpoint (taxonKey 2385648) — https://api.gbif.org/v1/species/2385648/iucnRedListCategory. Accessed 2026-09-23.

Description and natural history (Wikipedia)

Hemitaurichthys thompsoni is a medium-sized butterflyfish, the body is uniformly bluish grey in colour and it has the typical short snout and compressed body of species within the genus Hemitaurichthys. The dorsal fin contains 12 spines and 25-17 soft rays while the anal fin has 3 spines and 20-21 soft rays. This fish attains a maximum total length of 16 cm.

Hemitaurichthys thompsoni is found throughout most of Oceania, from the Bonin Islands, Guam and the Northern Mariana Islands, Taongi and Wake Atolls, southwards through Polynesia from the Hawaii and Johnston Island to Samoa, the Cook, Society and Tuamotu Islands. It may be more widely distributed.

Hemitaurichthys thompsoni occurs on coral reefs where it is usually observed on the outer-reef, the fore-reef slopes and at drop-offs. It can be found at depths between 4 and 300 m. It aggregates in schools high in the water column. It is an omnivorous species which feeds on plankton, although they mostly feed on zooplankton, particularly copepods. They will also feed on coral. It is an oviparous species and the male and female form pairs when breeding.

Hemitaurichthys thompsoni was first formally described in 1923 by the American ichthyologist Henry Weed Fowler (1878–1965) with the type locality given as Honolulu Fish Market. The specific name honours the artist and modeller John W. Thompson who worked at the Bishop Museum in Honolulu between 1901 and 1928 and who purchased the type and brought it to the Museum. This species has been known to hybridise with the pyramid butterflyfish (H. polylepis) in Hawaii.

Hemitaurichthys thompsoni is collected for the aquarium trade on a limited basis. However, its rather plain and relatively dull colouration mean that it is not as popular as related species of butterflyfish.

Source: Wikipedia: Hemitaurichthys thompsoni — https://en.wikipedia.org/wiki/Hemitaurichthys_thompsoni (CC BY-SA 4.0). Accessed 2026-09-23.