The Pyramid Butterflyfish is a deep-bodied, laterally compressed species marked by a brown-to-black head, brilliant yellow dorsal and anal fins, a white tail, and the broad white wedge along each flank that gives the fish its name. Adults reach roughly 7 inches. The species ranges widely through the Indo-Pacific, from the eastern Indian Ocean across Southeast Asia and southern Japan to Australia, Hawaii, and the Pitcairn Islands, where it occupies outer reef slopes and drop-offs. Unlike most butterflyfishes, it gathers in large open-water shoals that hover above current-swept reef faces, picking plankton from the water column rather than grazing on the reef itself.

Adult housing should begin at 100 gallons, with more volume strongly preferred for a pair or small group given how much time this fish spends cruising in the open. Design the layout around swimming room: a long, well-established system with generous water movement, an uncluttered midwater zone, and rockwork arranged to provide several retreats. Those hiding places matter most during the first weeks, since freshly imported specimens often behave shyly before settling in. This is a moderate-care species that rewards stable, mature water conditions and an experienced hand at the outset.