Heniochus.
The Pennant Butterflyfish, also known as the Heniochus Butterflyfish or Schooling Bannerfish, is a striking and popular addition to the marine aquarium. Its body is primarily white with two broad, diagonal black bands. A long, flowing white dorsal filament extends from the anterior dorsal fin, giving it a distinctive banner-like appearance. The caudal fin is yellow.
A minimum of a 75-gallon tank is recommended for a single specimen, with larger tanks needed for groups. Provide plenty of live rock for grazing and hiding places. While generally considered more reef-safe than many other butterflyfish, they may occasionally nip at stony corals, soft corals, and clam mantles, especially if not well-fed.
There are no distinguishable differences in color between male and female. The Pennant Butterflyfish is a omnivore and requires a varied diet of marine algae, spirulina, high-quality butterflyfish preparations, mysis shrimp, and other meaty foods. They can grow up to 8 inches in length in an aquarium.