The Copperband Butterfly (Chelmon rostratus) goes by several common names, including; the Beaked Butterflyfish, Beaked Coralfish and Orange Stripe Butterfly. Although surprisingly affordable, when considering the exquisite beauty this fish possesses, this fish is not one for the beginner. Success in keeping this delicate species varies between individuals. They can be finicky eaters and require very high water quality so are not recommended for novice aquarists.
Increasing your chances of successfully keeping this species starts before you even purchase one. When choosing a specimen in the aquarium store, look for a ‘fleshed out’ individual. The skeleton of the fish should not be visible. Ask the dealer if the fish is eating, a reputable dealer will allow you to see the fish being fed, if you ask. Ensure that you are able to replicate in your aquarium whatever the dealer is feeding in theirs. For example, live brine shrimp may not be the most practical thing to feed on a daily basis.
The Copperband Butterfly can reach a size of 20cm and should be kept in a tank of no less than 260 litres. If keeping a pair, then no less than 480 litres should be provided. Pairs should be added together to avoid aggression. Do not add individuals separately, as the individual added first will attack the second. A small group may be kept in a larger system of at least 1500 litres. The aquarium should have plenty of open swimming space and plenty of live rock to provide caves for the Copperband to retreat to if it feels threatened. The Copperband Butterfly is often purchased to rid an aquarium of pesky Aiptasia, which it does with great efficiency.
Copperband Butterfly fish are peaceful in nature and should not be housed with aggressive tangs (See: Guide to Tangs), butterflyfish or angelfish. The Copperband Butterfly is not considered reef safe, as it will nip at most sessile invertebrates and will feed on benthic invertebrates, such as tubeworms and small crustaceans, coral polyps, polychaete worms, feather dusters etc. However, this does not mean that these fish cannot be kept in a reef tank, it just means that certain individuals may prove problematic.
Copperband Butterfly fish do well with a variety of other less aggressive species but can be aggressive towards others of its own kind and towards other Chelmon species. It will usually be fine with other butterflyfish species but the occasional adult may become aggressive.
The small size of the Copperband Butterfly’s mouth makes its feeding habits slightly complicated, as it can only grab small particles of food. They should be fed mostly a carnivorous diet, consisting of finely chopped Mysis and Brine shrimp and other finely chopped meaty preparations. Japanese Nori (Asakusa-nori) may also be favoured. If at first they are having difficulty eating, they may be enticed to eat live foods offered in a way that simulates their natural feeding environment. Bloodworms pushed into rocks and corals, or live clams and black mussels with their shells cracked open have been reported as successful for these difficult eaters. At first, they are not aggressive feeders and may need to be enticed to eat with live foods before being weened onto prepared foods.
Disease and Quarantine
Unfortunately, the Copperband Butterfly along with other butterfly species, are especially susceptible to marine disease, so it is highly recommended that you introduce these fish into your main aquarium only after using quarantine procedures.