Teardrop butterflyfish

Lore & Background

The teardrop butterflyfish was first formally described in 1787 by the German medical doctor and zoologist Marcus Elieser Bloch, with the type locality given as the East Indies (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, and it is only distantly related to other Chaetodon species such as the sunburst butterflyfish (Chaetodon kleinii) and the Tahiti butterflyfish (Chaetodon trichrous).

The species has a whitish body with yellow dorsal, anal and pelvic fins, the yellow extending onto the back. The upper flank is marked with a large teardrop-shaped black blotch, and there is a wide black vertical bar through the eye. Delicate yellowish-orange chevrons appear on the flanks in front of the black teardrop, and another black vertical band 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.

Teardrop 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. They are oviparous and monogamous, with the sexes forming pairs to breed. They may be found at depths of 1 to 60 metres and are most numerous where the leathery corals of the genera Sarcophyton and Sinularia grow.

Reader's Guide

The teardrop butterflyfish is relatively common in the aquarium trade, making it a notable species for marine aquarists. It is also caught by some artisanal fisheries, indicating its role in local subsistence or small-scale commercial fishing. Its distribution spans the eastern Indian and western Pacific Oceans, from Christmas Island and Cocos (Keeling) Island east to Hawaii, the Marquesas and Ducie Island, north to southern Japan, and south to Lord Howe in the Tasman Sea and the central coast of New South Wales. This wide range underscores its adaptability to various reef environments, including reef flats, clear lagoons, and seaward reefs. The species' feeding habits—consuming soft and hard corals, polychaetes, small crustaceans, and filamentous algae—highlight its ecological role as a generalist omnivore on coral reefs. Its monogamous breeding behavior and oviparous reproduction contribute to its life history, while its preference for areas with leathery corals of the genera Sarcophyton and Sinularia suggests a specific habitat association. The taxonomic history, including its former subspecies status and distant relation to other Chaetodon species, adds scientific context to its classification.

Did You Know?

• It attains a maximum total length of 20 centimetres (7.9 in).
• It is monogamous, with sexes forming pairs to breed.