Gunther's Butterflyfish

Chaetodon guentheri has a body which is mainly white to pale yellow in colour and marked with small dark spots which create a pattern of irregular lines. The posterior part of the body, the soft-rayed part of the dorsal fin and the anal fin are yellow. A vertical black bar runs through the eye. The background colour to the body is whitest towards the head and becomes yellow towards the back and tail. The dorsal and anal fins also have a white band on the margin with a thin black band to the inside of that. The dorsal fin has 13 spines and 21-22 soft rays, while the anal fin contains 3 spines and 18 soft rays. This species attains a maximum total length of 18 centimetres (7.1 in).

Chaetodon guentheri is a species of the Western Pacific Ocean and it is found from southern Japan and Taiwan on the north south as far as New South Wales. It also occurs off Lord Howe Island, the Great Barrier Reef east to Tonga.

Chaetodon guentheri was first formally described in 1923 by the German zoologist Christoph Gustav Ernst Ahl (1898-1945) with the type locality given as Manado on Sulawesi in Indonesia. The specific name honours the German-born British zoologist, ichthyologist, and herpetologist Albert Günther (1830-1914) who first described this species as C. miliaris in 1871.