Smith's butterflyfish (Chaetodon smithi)

Classification (WoRMS)

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

Accepted name: Chaetodon smithi · Authority: Randall, 1975 · Taxonomic status: accepted · AphiaID: 273362.

Synonyms and superseded combinations recorded for this taxon: Chaetodon hemichrysus Burgess & Randall, 1978.

Source: World Register of Marine Species (WoRMS) — https://www.marinespecies.org/aphia.php?p=taxdetails&id=273362 (CC BY 4.0). Accessed 2026-09-23.

Biology and life history (FishBase)

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

Maximum length: 19 cm · Depth range: 0–80 m · Habitat zone: reef-associated · Body shape: short and / or deep · Vulnerability index: 10 of 100.

FishBase notes: Abundant in algal covered rocky reefs often in large aggregations (Ref. 9710). A mid-water plankton feeder (Ref. 4858). Oviparous (Ref. 205). Form pairs during breeding (Ref. 205).

Source: FishBase species summary (SpecCode 12648) — https://www.fishbase.se/summary/Chaetodon-smithi.html (CC BY-NC 3.0 — non-commercial use only). Accessed 2026-09-23.

Conservation status (IUCN Red List)

The IUCN Red List assesses Chaetodon smithi Randall, 1975 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 165675) — https://www.iucnredlist.org/species/165675/0; GBIF IUCN Red List category endpoint (taxonKey 2385384) — https://api.gbif.org/v1/species/2385384/iucnRedListCategory. Accessed 2026-09-23.

Description and natural history (Wikipedia)

Smith's butterflyfish has the anterior half of the body and associated fins are dark brown while the posterior half and fins are yellow. The posterior soft rayed part of the dorsal fin and the anal fin have blue margins. It attains a maximum total length of 18 cm. The separation of the two colour blocs on the body is irregular and the spines of the dorsal fin are also yellow over the brown anterior part of the body. It attains a maximum total length of 19 cm.

Smith's butterflyfish is endemic to the south western Pacific Ocean where it has only been recorded from the British Overseas Territory of Pitcairn Island and Rapa Iti and Marotiri, the Ilots de Basse, in French Polynesia. There has been a single confirmed record from Easter Island.

Smith's butterflyfish occur on rocky reefs with dense growth of algae and at least a little coral. It is often encountered in large aggregations in the middle of the water column where they feed on zooplankton. This oviparous species forms pairs for breeding.

This species was described in 1975 by the American ichthyologist John Ernest Randall (1924-2020) with the type locality given as off Young's Rock, Pitcairn Island. The type specimens were collected by the ichthyologist C. Lavett Smith, Jr. (1927-2015) of the American Museum of Natural History and whom Randall honoured with its specific name.

This species does appear in the aquarium trade but is extremely rare in that trade. It is on display at the Waikiki Aquarium.

Source: Wikipedia: Smith's butterflyfish — https://en.wikipedia.org/wiki/Smith%27s_butterflyfish (CC BY-SA 4.0). Accessed 2026-09-23.