Saddle butterflyfish

Lore & Background

The saddle butterflyfish was first formally described in 1831 by the French anatomist Georges Cuvier, with the type locality given as Bora Bora in the Society Islands. It belongs to the large subgenus Rabdophorus, which might warrant recognition as a distinct genus. Within this group, it appears to represent a distinct lineage, with the dotted butterflyfish (Chaetodon semeion) perhaps the only somewhat closely related species. Next closest seems to be a group including the blackback butterflyfish (C. melannotus), spot-tailed butterflyfish (C. ocellicaudus) and yellow-dotted butterflyfish (C. selene), but these are already so distant that their ancestors must have diverged from the saddle butterflyfish's soon after the Rabdophorus lineage started to diversify.

Reader's Guide

The saddle butterflyfish is significant as one of the giants among its genus, reaching up to 30 cm in length, together with the lined butterflyfish. Its shape resembles certain angelfishes more than most of its relatives. The overall color is yellowish grey, with a large black spot bordered below by a broad white band on the back and wavy blue lines on the lower sides. The throat and the outline of the hind parts are bright yellow. Adults have a filament extending posteriorly from the upper part of the soft portion of the dorsal fin. It is found at depths between 0 and 30 m in coral reefs, feeding on filamentous algae, small invertebrates, coral polyps, and fish eggs. Its distribution spans the Indian and Pacific Oceans from Sri Lanka and the Cocos-Keeling Islands to the Hawaiian, Marquesan and Tuamotu islands, north to southern Japan, south to Rowley Shoals and New South Wales in Australia. The species' placement within the subgenus Rabdophorus suggests a distinct evolutionary lineage, with only the dotted butterflyfish as a possibly close relative.

Did You Know?

• The saddle butterflyfish can reach up to 30 cm in length, making it one of the largest butterflyfishes.
• It was first described in 1831 by French anatomist Georges Cuvier from a specimen collected at Bora Bora.