5590 Heniochus monoceros Cuvier, 1831 Chaetodontidae Butterflyfishes Acanthuriformes Teleostei Masked bannerfish Indo-Pacific: East Africa to the Tuamoto Islands, north to southern Japan, south to New South Wales and Tonga. AMNH 90123 Heniochus monoceros 15 N 124 E 2014 Heniochous monoceros 54.4 m