Chelmon muelleri

Chelmon muelleri, commonly known as the Blackfin coralfish, is a medium-sized butterflyfish which looks very similar to the more well-known C. rostratus. Their base colour is silvery-white with silvery-grey small spots making scribbled horizontal lines. Over this white base colour, they've 4 vertical rusty brown bands with a little faint black outline. The pelvic fins are black and they've a very long nose/mouth to pick food from small crevices which has some yellow on it. 

These fish are quite peaceful to most other fish, but might haress similar looking fish. They live usually in pairs over algae covered mud bottoms. In an aquarium they can best be kept alone unless a proven pair can be found. They're real omnivores feeding on small benthic invertebrates in nature, and are well known Aiptasia eaters (although some individuals might refuse to eat them). Unfortunately, like C. rostratus they're notoriously hard to wean onto food after shipping. Only buy fish that have a fat belly and do eat, and even then be prepared it might stop eating once you add them to your tank. Tempt them with live artemia or mysis, before switching them to a varied diet of frozen food. They can be a little shy in the beginning, so make sure it eats well before adding aggressive and fast eating fish to the tank. Except for tubeworms, most individuals only nip on corals but don't do real damage, but rogue individuals might haress soft coral and LPS!