Chaetodon sedentarius also commonly referred as Reef Butterflyfish, Butterbun and Least Butterflyfish has a silver body, yellow and black dorsal fin, and yellow tail. There are two distinguishing vertical black bars on the body. One is on the head and runs down through the eye. The other one runs down along the rear of the body, including the rear portion of the dorsal and anal fins. Juvenile reef butterflyfish differ in coloration as the dark posterior area may be faded revealing two rounded spots.
The Reef Butterflyfish is a tropical western Atlantic species, found in the waters of the Carolinas to northern South America, including the Gulf of Mexico and the Caribbean Sea.
Cheatodon sedentarius gets its name from its flitting movements about the reef and its beautiful color pattern that resembles the movements and appearance of the insect. The reef butterfly is a highly compressed species, designed for maneuverability and short bursts of speed, not for endurance swimming.
Cheatodon sedentarius scraping and nipping at small invertebrates, including polychaete worms, shrimps, and amphipods, that make up its diet.
The Reef Butterflyfish, as its name suggests, is primarily a reef species. The reef provides plenty of hiding spaces for these fishes as well as good habitat for the small invertebrates on which it feeds. Its depth distribution coincides with the limits of coral growth; it can live in the shallows and as deep as the light restricts coral growth. Generally it inhabits deeper parts of the reef 15-40 meters than other species of butterflyfish in the area.
Butterflyfish are not recommended for reefs as they will pick at or eat a wide variety of corals, fan worms, and other invertebrates. Most Butterflyfish are known to pick at Aiptaisia, a parasitic anemone.
Chaetodon gracilis Günther, 1860