Exploring the Unique Chelmon muelleri: The Blackfin Coralfish
I was lucky enough to spot an adult Chelmon muelleri while visiting DeJong Marinelife last year. Although not a super rare import, the pictured fish stood out for its size, health and presence in one of their broodstock tanks, and the fact that it was part of a pair.
Known as the Blackfin Coralfish, Muller’s Coralfish, or the Australian Copperband, Chelmon muelleri is indeed related to the Copperband butterflyfish, and looks like it, at a glance. It has the characteristic body shape, orange vertical bars and ocellus of the Copperband, only muelleri has a shorter snout, develops dark shading on the latter half of its body, and adults develop a distinctive nuchal hump.
They inhabit the Coastal reefs and estuaries of Queensland and northwestern Australia, taking them into harbors and even brackish waters. Their habitats consist of algae and mud, where they dine on small benthic invertebrates. As to where this would leave them with coral polyps (and Aiptasia,) I don’t know, but judging by the fact that I’ve never seen one in a reef aquarium, I’m going to say they’re not reef safe. They’re almost too nice for the rough and tumble of the average fish-only saltwater aquarium too, so the ideal theme, for me, would be one that replicates a harbour with some jetty posts perhaps, and seaweed.
They attain a length of 18cm and this one was fully grown. And if you like people with titles, it Chelmon muelleri is named in honour of Baron Dr Sir Ferdinand Jacob Heinrich von Müller (1825–1896), who was a German-born Australian botanist, geographer, explorer, physician, and naturalist. It was first placed within the genus Chaetodon when first described in 1879. Its congeners in Chelmon are C.rostratus and C.marginalis. It resembles some members of Coradion too.
