Pyramid butterflyfish (Hemitaurichthys polylepis)

Classification (WoRMS)

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

Accepted name: Hemitaurichthys polylepis · Authority: (Bleeker, 1857) · Taxonomic status: accepted · AphiaID: 277575.

Synonyms and superseded combinations recorded for this taxon: Chaetodon polylepis Bleeker, 1857.

Source: World Register of Marine Species (WoRMS) — https://www.marinespecies.org/aphia.php?p=taxdetails&id=277575 (CC BY 4.0). Accessed 2026-09-23.

Biology and life history (FishBase)

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

Maximum length: 18 cm · Depth range: 0–60 m · Habitat zone: reef-associated · Body shape: short and / or deep · Vulnerability index: 10 of 100 · Fishery importance: commercial · Aquarium trade: commercial.

FishBase notes: Occur in large schools that may extend several meters above the edges of steep current-swept outer reef slopes. Common (Ref. 9710). Benthopelagic (Ref. 58302). Feed on plankton (Ref. 3921). Oviparous (Ref. 205). Form pairs during breeding (Ref. 205).

Source: FishBase species summary (SpecCode 5586) — https://www.fishbase.se/summary/Hemitaurichthys-polylepis.html (CC BY-NC 3.0 — non-commercial use only). Accessed 2026-09-23.

Distribution and occurrence records (GBIF)

1,943 georeferenced occurrence records for Hemitaurichthys polylepis are published through GBIF from 30 countries or marine areas. The map above plots 288 distinct locations from a sample of 1,943 records, omitting 20 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: Australia (356); Indonesia (305); United States of America (220); French Polynesia (139); Northern Mariana Islands (128).

The full country table, WoRMS marine regions and the sampling notes are on this species' Distribution page.

Source: GBIF Occurrence Search (taxonKey 2385640) — https://www.gbif.org/occurrence/search?taxon_key=2385640&has_coordinate=true (records CC0 / CC BY); WoRMS distribution records (MarineRegions) — https://www.marinespecies.org/aphia.php?p=taxdetails&id=277575 (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 polylepis (Bleeker, 1857) 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 165672) — https://www.iucnredlist.org/species/165672/0; GBIF IUCN Red List category endpoint (taxonKey 2385640) — https://api.gbif.org/v1/species/2385640/iucnRedListCategory. Accessed 2026-09-23.

Description and natural history (Wikipedia)

The pyramid butterflyfish is a small-sized fish that can reach a maximum length of 18 cm.

Its body is compressed laterally with a rounded body profile, and its snout protrudes forwards slightly with a small protrusible (extendable) mouth. Its very characteristic livery leaves no doubt about the identification. A dark brown-yellow area, the colour of which may vary in intensity, fully masks the head and extends to a line from the first rays of the dorsal fin to the start of its pelvic fins.

The rest of its body is white, peduncle and caudal fin included. Insertion of yellow-orange areas at the top of the side form a characteristic pyramidal pattern, hence the name of the fish. The anal fin is also yellow-orange.

The pyramid butterflyfish is widespread throughout the tropical and subtropical waters of the central Indo-Pacific from Cocos Keeling and Christmas Island to Polynesia and from south Japan to New-Caledonia.

The pyramid butterflyfish appreciates the outer reef slopes from which it can swim out into open water to get its food. It can be seen at depths from 3 to 60 meters deep.

The pyramid butterflyfish lives in large schools, and feeds on plankton in open water out of its shelter reef.

The species as a planktivorous could be affected by climate-induced reductions in planktonic productivity. There do not appear to be any current threats to this species and it is listed as Least Concern (LC) by the IUCN.

Source: Wikipedia: Pyramid butterflyfish — https://en.wikipedia.org/wiki/Pyramid_butterflyfish (CC BY-SA 4.0). Accessed 2026-09-23.