News / Species Spotlight / Revisited: Copperband Butterflyfish (02/05/14)

Revisited: Copperband Butterflyfish

by Charles J. Hanley III

Scientific Name: Chelmon rostratus

Common Name(s): Copperband Butterflyfish, Copperbanded Butterflyfish, Beaked Butterflyfish, Long-Nosed Butterflyfish, Beaked Coralfish, Orange-Stripe Butterflyfish.


Scientific Name: Chelmon rostratus

Common Name(s): Copperband Butterflyfish, Copperbanded Butterflyfish, Beaked Butterflyfish, Long-Nosed Butterflyfish, Beaked Coralfish, Orange-Stripe Butterflyfish.


At times, it seems like the aquarium hobby takes a very regimented view on husbandry issues. Take a look at some aquarium writings, and you will quickly see what I mean. Depictions of next species spotlight subject, the Copperband Butterflyfish (Chelmon rostratus), vary from exceptionally hard-to-keep coral eaters, to somewhat sensitive and basically reef-safe. You really cannot run the gamut more than thatthere is no way that all that can true, right? Wellno, not exactlythough the copperband may be one of the most unpredictable species of aquarium fish, at least from one individual to another. Hopefully, this article sheds some light on what is an unnecessarily confusing subject.

First, let us start with a basic description of the copperband. Like other butterflyfish, the copperband is a tall, slender fish that resembles a disc or a spade. Generally, fish with this morphology are very agile because the body functions almost like a sideways wing. They can dart around and make very sharp turns, an ability that helps copperbands maneuver in and out of the various nooks and crannies of a coral reef. Their long, narrow snouts allow them to probe deep into holes and crevices, where they seek out their preferred diet of Aiptasia anemones and polychaete worms. Copperbands have some of the most vivid and beautiful markings of any marine fish, with 5 vertical copper-orange bars set against a pearl-white background. The bars get wider, moving from the eye to the tail. Around the center of dorsal fin, these fish flash a deep black false eyespot that is typically surrounded by a thin rim of blue-white. At the base of the translucent caudal fin, a vertical black band spans the caudal peduncle. Due to their spade shape, butterflyfish are often confused with angelfish. However, they are distinguishable by the absence of a prominent operculum spine. Copperband butterflyfish are smaller than many other butterflies, reaching a maximum fork length of around 8 inches.

Natural Habitat and Ecology:

Copperband butterflyfish are found in a fairly wide geographical range within the tropical Indo-Pacific region. They inhabit waters as far west as the Andaman Sea, near eastern India, and as far east as Papua New Guinea. They are even found in the waters around Madagascar, and the eastern coast of the African continent. From north to south, they extend from Japans Ryuku Islands to Australias northeastern and northwestern coasts, including the Great Barrier Reef.

As previously mentioned, copperbands are found around tropical reefs, usually flitting in and out of tight spaces. They are a diurnal species which actively searches for food during the day. Their morphology is well-suited to the endeavor of plumbing crevices for tiny morsels of meaty food. Almost exclusively carnivorous, these butterflyfish are known to be picky eaters. In the wild, they primarily prey upon glass anemones (Aiptasia sp.) and polychaete tube worms. They also eat small crustaceans, and even coral polyps. At night, they rest in sheltered nooks on the surface of the reef. Usually found in waters between 1 and 25 meters deep, copperband butterflyfish prefer to inhabit silted inner and coastal reefs. They are even occasionally found in brackish estuaries.

Similar to many other species of butterflyfish, copperbands can form monogamous pair bonds. These bonds may last anywhere from a few months to life. Though they have similar appearances, there is some minor sexual dimorphism that distinguishes males from females. Compared to the female, the males forehead is steeper and the snout more horizontal. An individual will tolerate the presence of its mate, but will aggressively defend its territory from other butterflyfish. For this reason, and possibly others, copperband butterflyfish are not successfully bred in captivity.

Aquarium Care:

Admittedly, aquarium care can be tricky where copperbands are concerned. They are sensitive to water quality and it can be hard to get them to accept food. Fortunately, they are far from impossible, and it normally takes just a little extra TLC to keep them happy and healthy. At this point in the hobby, a majority of marine aquarists are more than capable of keeping a clean enough tank for these sensitive subjects. Food options are also so numerous that even picky fish can be enticed to eat. If you can fulfill a few basic requirements when choosing a copperband butterflyfish, you are likely to have success keeping it alive and healthy. A good approach always includes planning ahead, because an easy transition into a suitable environment will dramatically improve the odds of success. Here are some simple steps to take:

1) Consider Tank Size. It is generally recommended that copperband butterflyfish be kept in a tank with a minimum size of 75 to 100 gallons. Though size alone does not dictate needing a tank that large, the water quality demands are much more easily fulfilled in a greater volume. The additional space helps to slow parameter changes, as well as offset the excess feeding that a copperband is likely to need. The extra space for live rock also increases the butterflys feeding opportunities by providing more habitat space for polychaete worms and small crustaceans.

2) Ask Yourself Why you Want a Copperband. The recent trend amongst copperband owners is to use them as form of pest control to eliminate troublesome Aiptasia anemones. This makes sense, as glass anemones are a favorite food of copperbands in the wild. If you too are intending to do this, consider the amount of Aiptasia that are actually in your system. If your fish decides to eat them (an outcome that is not at all guaranteed with these picky eaters), it will do so voraciously, making short work of whatever Aiptasia are present. There is very little chance that a tank on its own has enough glass anemones and polychaetes to support this constantly grazing fish species.

3) Plan a Good Feeding Regimen. Copperbands are picky eatersthere are no two ways about it. Regardless of the severity of an Aiptasia outbreak, you will need to provide meaty meals every day. Though some individuals do well on frozen diets, they all prefer live food. In fact, many specimens will refuse to take anything but live offers. It is not impossible to wean the fish onto frozen foods, but again, individuals vary greatly. Interestingly, I discovered one anecdotal report of a copperband refusing Aiptasia, only to learn how to eat them when the aquarist inserted that fishs favorite food into an anemone at feeding time. The butterflyfish eventually acquired a taste for the polyp, and no longer needed to be enticed to feed upon them. Overall, a mixed diet of brine and mysis shrimp, algae, and squid meat will help ensure the proper nutrition. I always recommend soaking foods daily in an omega-3 fatty acid supplement like Selcon as well, and in fresh garlic oil at least once a week.

4) Evaluate Individuals at the Store Before Purchase. This is a solid recommendation for any livestock purchase, not just copperband butterflyfish. Ask the salesperson to feed the fish for you. Healthy animals should readily accept food, and should be active and alert. Look for a robust, full body shape, eye clarity, excellent coloration, and clean fins. Avoid fish that refuse to eat at the store, look thin or ragged, and have evidence of marine Ich, fin rot, and other visible lesions or parasites. It is also a good idea to try and buy larger specimens, as they tend to better acclimate to new surroundings.

5) Quarantine. Quarantine tanks not your style? It might be time to change that opinion. Using a quarantine period before introducing your copperband is an excellent idea. It gives you the opportunity to establish whether the fish has any health problems, and to treat it accordingly. There is no need to risk bringing pathogens into your main tank if a method exists by which the possibility is eliminated. The quarantine time is also a great chance to convert to frozen foods, if necessary. For a detailed explanation of quarantine procedures, check out this past article.

6) Keep the Peace. Copperband butterflyfish are territorial with other butterflyfish, so avoid putting more than one in a tank unless they are an established pair. Fortunately, this species is also quite peaceful with other types of fish, and so can be considered a good addition to a community tank. Some aquarists prefer to introduce fish two-at-a-time to better spread territorial aggression from previous inhabitants. It is critical to note that copperbands are reported to nip at coral polyps. This is not a true statement for all copperbands, and likely not even most of them. They are not nearly as notorious for eating corals as other species of butterflyfish, but individuals do vary. It may be that this species turns to eating coral polyps when adequate nutrition is not otherwise available. A well fed specimen is not likely to be a problem in a large reef tank.

7) Filtration, Filtration, Filtration. A combination of good water flow, efficient mechanical filtration, excess protein skimming, and UV sterilization are all excellent mechanisms for providing clean, parasite-free water. Clean water is imminently achievable in a number ways, but UV sterilization should be considered an absolute must for sensitive fish.

8) Maintain Stable Water Conditions. Specific parameters are not as critical as stability, as far as water quality goes. Standard fish-only or reef tank conditions are fine. Temperatures should be kept between 75 and 82 degrees Fahrenheit, pH maintained in the range of 8.1 to 8.4, and salinity kept from 1.020 to 1.024 SG. Though not appropriate for reef tanks, fish-only systems often benefit when salinity is lowered to the bottom end of the recommended range.

When caring for a copperband butterflyfish, the path to triumph is not mysterious or out of the ordinary. As long as they are kept with consistency and an excellent diet, there is no reason why most aquarists with a big enough tank could not have one. It is not a matter of whether or not the average person can fulfill their needs; it is about whether the average person is willing to do it on a daily basis.

Works Cited:

Anderson, Tim. Copperband Butterflyfish. Website. 2009. URL: <>

Anonymous. Copperband Butterfly Fish. Website. 2007. URL: < >

Anonymous. Copperband Butterflyfish. All About Fish, Website. 2008. URL: <>

Anonymous. Copperbanded Butterflyfish. Website. URL: <>

Froese, Rainer. Chelmon rostratus (Linnaeus, 1758). Catalog of Fishes. 2010. URL: <>

Gaines Kevin. Quarantine Procedures for New Fish and Invertebrates. Website. 2009. URL: <>

Goemans, B. and L. Ichinotsubo. The Marine Fish Health and Feeding Handbook. T.F.H. Publications; Neptune City. 2008.

Jennings, Greg. The New Encyclopedia of the Saltwater Aquarium. Firefly Books; Buffalo. 2007.

Leroy. Control of Aiptasia in Reef Aquariums Tanks. Website. URL: <>

Lieske, E. and R. Meyers. Coral Reef Fishes, Revised Edition. Princeton University Press; Princeton. 2002.

Oliver, Michael K. (editor). Simon & Schusters Guide to Freshwater and Marine Aquarium Fishes. Simon & Schuster; New York. 1977.

Staff. Probing for Food: Copperband Butterfly Fish. Ask Nature Beta Website. 2010. URL: <>

Tullock, J.H. Natural Reef Aquariums. T.F.H. Publications; Neptune City. 2001.