The Mertensii Butterfly (Chaetodon mertensii), also known as the Crowned Pearlyscale Butterfly, is a beautiful fish found among the reefs of the Indo-Pacific Ocean. They have a light silver body with vertical black stripes, a yellow posterior and yellow tips along their dorsal fin. They may be kept with other butterflies, though they may fight with others of their kind. They are not recommended for reef aquariums, as they may nip at soft corals and polyps. Their diet should consist of occasional seaweed, crustaceans and other vitamin-enriched preparations. They reach a maximum size of 6 inches and should not be kept with overly aggressive fish.