Speckled butterflyfish

Lore & Background

The speckled butterflyfish is described as pale yellow with numerous small dark spots, a black bar extending above and below the eye, and a black margin to the anal fin. The largest recorded specimen was 13 centimeters (5.1 in) long. It is common in shallow exposed reef flats, lagoons, and seaward reefs, generally in relatively open areas with scattered corals, and may occasionally be found as deep as 36 meters (118 ft).

Adults usually swim in pairs, which form during breeding, while juveniles are more often seen in small aggregations and commonly mix with other similar-sized juveniles, especially of the sunburst butterflyfish (C. kleinii). The species is oviparous.

Phylogenetically, C. citrinellus is a distinct species most closely related to the fourspot butterflyfish (C. quadrimaculatus). Together they are basal in the subgenus Exornator, and might be intermediate between the core group of this subgenus and the species of the Rhombochaetodon (or Roaops) lineage. If that is correct, the latter would require to be merged into Exornator. If the genus Chaetodon is split up, Exornator might become a subgenus of Lepidochaetodon.

Reader's Guide

The speckled butterflyfish is significant for its role in understanding the evolutionary relationships within the genus Chaetodon. According to the source article, it is most closely related to the fourspot butterflyfish, and together they are considered basal in the subgenus Exornator. This placement suggests they may be intermediate between the core Exornator group and the Rhombochaetodon (or Roaops) lineage, a hypothesis that, if correct, would require merging the latter into Exornator. Furthermore, if the genus Chaetodon is split, Exornator might become a subgenus of Lepidochaetodon. Ecologically, the species is common in shallow Indo-Pacific reef environments, from the Red Sea and East Africa to Hawaii and Australia. Its diet includes small worms, benthic invertebrates, coral polyps, and filamentous algae. Adults form pairs during breeding, while juveniles aggregate and often mix with sunburst butterflyfish juveniles. The species is oviparous. Its maximum recorded length is 13 cm, and it can be found as deep as 36 meters.

Did You Know?

• The speckled butterflyfish is also known as the citron butterflyfish.
• Juveniles commonly mix with juveniles of the sunburst butterflyfish (C. kleinii).