Teardrop butterflyfish (Chaetodon unimaculatus)

Classification (WoRMS)

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

Accepted name: Chaetodon unimaculatus · Authority: Bloch, 1787 · Taxonomic status: accepted · AphiaID: 218753.

Synonyms and superseded combinations recorded for this taxon: Chaetodon sphenospilus Jenkins, 1901; Heterochaetodon lepidochaetodon unimaculatus (Bloch, 1787).

Source: World Register of Marine Species (WoRMS) — https://www.marinespecies.org/aphia.php?p=taxdetails&id=218753 (CC BY 4.0). Accessed 2026-09-25.

Biology and life history (FishBase)

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

Maximum length: 20 cm · Common length: 16 cm · Depth range: 1–60 m · Habitat zone: reef-associated · Body shape: short and / or deep · Vulnerability index: 10 of 100 · Fishery importance: minor commercial · Aquarium trade: commercial.

FishBase notes: Occur in small groups in reef flats, clear lagoon and seaward reefs (Ref. 48636). Benthopelagic (Ref. 58302). Feed on soft and hard corals, also on polychaetes, small crustaceans, and filamentous algae. In Indonesia, usually seen at moderate depths, usually swimming in small groups.

Adults are mainly in depth 20-60 m (Ref. 48636). Oviparous (Ref. 205), monogamous (Ref. 52884). Form pairs during breeding (Ref. 205).

Source: FishBase species summary (SpecCode 5581) — https://www.fishbase.se/summary/Chaetodon-unimaculatus.html (CC BY-NC 3.0 — non-commercial use only). Accessed 2026-09-25.

Distribution and occurrence records (GBIF)

5,463 georeferenced occurrence records for Chaetodon unimaculatus are published through GBIF from 45 countries or marine areas. The map above plots 282 distinct locations from a sample of 3,000 records, omitting 26 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 (1,344); United States of America (901); French Polynesia (847); American Samoa (480); United States Minor Outlying Islands (316).

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

Source: GBIF Occurrence Search (taxonKey 2385331) — https://www.gbif.org/occurrence/search?taxon_key=2385331&has_coordinate=true (records CC0 / CC BY); WoRMS distribution records (MarineRegions) — https://www.marinespecies.org/aphia.php?p=taxdetails&id=218753 (CC BY 4.0); Natural Earth 110m basemap — https://www.naturalearthdata.com/ (public domain). Accessed 2026-09-25.

Conservation status (IUCN Red List)

The IUCN Red List assesses Chaetodon unimaculatus Bloch, 1787 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 165714) — https://www.iucnredlist.org/species/165714/0; GBIF IUCN Red List category endpoint (taxonKey 2385331) — https://api.gbif.org/v1/species/2385331/iucnRedListCategory. Accessed 2026-09-25.

Description and natural history (Wikipedia)

The teardrop butterflyfish has a whitish body with yellow dorsal, anal and pelvic fins, this yellow colour extends on to the back. The upper flank is marked with a large teardrop shaped black blotch and there is a wide, black, vertical bar though the eye.

There are delicate yellowish-orange chevrons on the flanks in front of the black teardrop and there is another black vertical band with runs from the rear of the dorsal fin, across the caudal peduncle to the rear of the anal fin. The dorsal fin contains 12-13 spines and 19-23 soft rays while the anal fin contains 3 spines and 18-20 soft rays. This species attains a maximum total length of 20 cm, although around 16 cm is more usual.

Distribution

The teardrop butterflyfish is found in the eastern Indian and western Pacific Oceans from Christmas Island and Cocos (Keeling) Island east as far as Hawaii, the Marquesas and Ducie Island, north as far as Southern Japan, and south to Lord Howe in the Tasman Sea and the central coast of New South Wales.

Habitat and biology

Teradrop butterflyfish are normally encountered in small groups in reef flats, clear lagoon and seaward reefs where they feed on soft and hard corals, as well as polychaetes, small crustaceans and filamentous algae. This is an oviparous species and they are monogamous with the sexes forming pairs to breed. These fishes may be found at depths of 1 to 60 m and they are most numerous where the leathery corals of the genera Sarcophyton and Sinularia grow.

Taxonomy

The teardrop butterflyfish was first formally described in 1787 by the german medical doctor and zoologist Marcus Elieser Bloch (1723-1799) with the type locality give as the East Indies, i.e. Indonesia. In the western Indian Ocean it is replaced by the yellow teardrop butterflyfish (Chaetodon interruptus), now a separate species but previously considered a subspecies of Chaetodon unimaculatus.

In its subgenus Lepidochaetodon it is sometimes considered a separate genus. It is only distantly related to other Chaetodon species such as the sunburst butterflyfish (Chaetodon kleinii) and the Tahiti butterflyfish (Chaetodon trichrous).

Utilisation

The teardrop butterflyfish is relatively common in the aquarium trade. It is caught by some artisanal fisheries.

Source: Wikipedia: Teardrop butterflyfish — https://en.wikipedia.org/wiki/Teardrop_butterflyfish (CC BY-SA 4.0). Accessed 2026-09-25.