(Image credit: Erik Schlögl)
The blackback butterflyfish has the characteristically rounded rectangle butterflyfish body shape. Fins are white body with yellow edges. A black portion on the rear dorsal surface fades away to form black lines running diagonally towards the head and pelvic fin area. These solid lines eventually become dotted lines on the belly. A black band with yellow edges runs across its eyes. Fin edges on the caudal fin are transparent. Pectoral fins are also transparent with a yellow base.
When startled, or at night, the dorsal section of the butterflyfish changes colour to black with two white blotches. During the day these blotches can be vaguely seen.
Length: Up to 18 cm
Reef flats and edges; 1-30 m depth
In New South Wales, log if spotted in Port Stephens and south
Species names on the Redmap site are based on the Codes for Australian Aquatic Biota or CAAB (http://www.cmar.csiro.au/caab/). This is updated regularly and lists the approved common name, family, species name and more.
Find further information and images at FISHES OF AUSTRALIA http://www.fishesofaustralia.net.au/
Randall, John; Allen, Gerald; Steen, Roger (1997). Fishes of the Great Barrier Reef and Coral Sea. University of Hawaii Press. p. 164. ISBN 0-8248-1895-4.