The longsnout butterflyfish (Prognathodes aculeatus) lives in tropical Atlantic waters at a depth down to 100 m. Most of the time it spends in grooves where there are many invertebrates. This species swims with sharp fluctuating movements. It actively feeds during the day and at sunset. Its diet consists of sea urchins, zooplankton, worms, and polyps.
The butterflyfish has a flat body with one high dorsal fin. A small mouth has tiny bristly teeth. The jaws extend into a long snout, which helps to find food in the reef cracks and at the bottom.
The upper half of the butterflyfish is yellow. Around the dorsal fin, the color changes to a brown-orange tone. The lower body and head are blond. There is a band from dark to yellow color that runs vertically from the top of the head to the eyes. At night, the color of the fish darkens, and in the daytime comes back. The pelvic and anal fins are yellow, the dorsal fin is black with a yellow edge, the caudal and pectoral fins are transparent.
Chaetodon aculeatus, Chaetodon unicolor, Chelmo pelta, Chelmon aculeatus