Copperband Butterflyfish - Chelmon rostratus

Updated August 6, 2019
Author: Mike - FishLore Admin
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The Copperband Butterflyfish is one of the more difficult marine fish to keep in the home aquarium and is definitely not recommended for a saltwater beginner. Only introduce a Copperband to a long established tank (6 months or more) with peaceful tank mates. If you have a new tank and it is still going through the aquarium nitrogen cycle, you can kiss this baby good bye.

Copperband Butterflyfish Copperband Butterflyfish


They are very delicate and it can be very difficult to get them eating. Always ask to see this fish eating in the store before you buy it! You may need to experiment with various live foods, including brine shrimp and mysis shrimp. Some hobbyists have reported success using fresh clams on the half shell placed in the bottom of the tank to get them to start eating.

Physically, the Copperband Butterflyfish is a very beautiful white with copper bands running vertically on the sides of the body. They have a "false eye" towards the back of the dorsal fin and can get up to about 8 inches (20 cm). They should play nicely with other, peaceful tank mates but will not tolerate other butterfly fish in the same tank.

Copperbanded Butterflyfish Copperband Butterflyfish

Since they are so delicate they come down with the typical saltwater fish diseases. You need to take proper pre-cautions by using a quarantine tank before introducing them into your main tank. Take your time while acclimating them to the tank. Keep your Copperbanded Butterflyfish in the hospital tank for two weeks or so and watch for obvious saltwater diseases, like marine ich. This will also give them time to recuperate from transport and it may be easier to get your Copperbanded Butterfly eating without competition from other tank mates.

Copperband Butterflyfish Chelmon rostratus

Copperband Butterflyfish Care

Scientific Name : Chelmon rostratus

Common Names : Beaked Coralfish, Copper-banded Butterfly Fish

Care Level : Difficult

Size : Up to 8 inches (20 cm)

Life span : 4 years or longer

pH : 8.1 - 8.4

Temperature : 75°F - 82°F (25°C - 28°C)

Specific Gravity : 1.020 - 1.025

Carbonate Hardness (dKH) : 8 - 12°

Origin / Habitat : Indian Ocean, Indo-Pacific, Australia

Temperament / Behavior : They can be aggressive with other butterfly fish.

Breeding : Very difficult to breed in captivity.

Aquarium Size : 75 gallon (284 liters) minimum

Tank Mates : Use caution when selecting tank mates. Avoid keeping a Copperband Butterflyfish with other butterfly fish and they may not be a good choice for saltwater reef tanks. May nip at soft corals. Try to keep them with some of the more peaceful marine species.

Fish Disease : Saltwater Fish Disease - Diagnose, Symptoms and Treatment

Food : Primarily carnivorous, try to give your Copperband Butterflyfish a variety of marine foods, including brine and mysis shrimp. In the ocean they use their long jaws to probe for prey in crevices. They will eat aiptasia (glass anemones). It can be very difficult to get them to start eating. You may need to feed live foods exclusively until well acclimated to your tank and then try to wean them onto frozen and flake foods.

Tank Region : Usually middle to bottom

Gender : Difficult to determine the differences between males and females.

Forum : Saltwater Butterfly Fish Forum

Photo Credit : Photos copyright

Site References :

Copperband Butterflyfish Comments

From: Peter
I have an 8 month old tank, 300 litres with 2 bubble tip anenomes, 2 purple tips and 2 elegance corals, 1 open brain coral, 1 cose brain coral, 1 yellow tang, 1 sailfin tang, 3 anthias, 1 dottyback, 2 blue devil damsel fish and 2 porcelain crabs, 2 black clownfish, 1 orange clownfish, 1 boxing shrimp, 1 black hairy crab that is a nuisance. The copper band is new and I will let you know how the intro goes. The tank mates are all happy and the copperband ate today after 12 hours after being introduced into the tank.

From: Marine
I had a Copper band butterfly fish and it died. Take it from a fish expert, you better have PERFECT water quality. I have Raised brackish, freshwater, saltwater, and coldwater fish and I have never had a fish that required more maintenance. Believe me when I say this: LEAVE IT TO THE PRO'S!

From: Vic
I have a 90 gal tank with 100lbs live rock and 100 lbs live sand..about two inches at the bottom. I have about 75 snail, 25 blue leg hermit crabs, a diamond goby to keep the sand clean, a cleaner shrimp to take care of the ich that may come into the tank, and a copperbanded butterfly. They're really not that hard to keep if you ask me, just make sure your system is up and running and do water changes every other weekend and the fish should be just fine. I've owned two, and neither one had any problem eating at all... they know what the food bowl looks like, and are always very excited to eat with the other fish/shrimp in the tank.

From: Tyler
I have a 55 gallon tank with two false percs, a sailfin tang, a three stripe damsel and a coral beauty angelfish. Today I got a copperband. So far he is a great addition. As soon as I put him in the tank he made friends with everyone and stayed out in the open. I did a transfer about a week ago with all my stuff from my 29 into the 55. About twenty mins after I got the copperband he was already picking through the rocks looking for food. Yet he hasn't touched any pellets or frozen foods yet. So far so good and I really don't believe they are the difficult fish to keep everyone says they are.
There are a few problems here... No mention of a quarantine tank could spell disaster for the other fish in the tank if your new copperbanded butterfly has something, which may not show up for a few days.

Another problem is that you mention a transfer from a 29 gallon to your current 55 gallon. There had to be some sort of die-off (ammonia/nitrite spike) in the substrate during the transfer along with the addition of more substrate materials to cover the larger tank's bottom area. Hopefully it won't, but it could pose problems for your fish while your tank is stabilizing. Please test often and do water changes as needed.

The Sailfin Tang needs a much larger tank, over 125 gallons (473 liters) and preferably larger given the potential adult size of this species.

It could take a couple of days before the copperband starts eating. Keep trying the frozen foods and maybe with the other fish in the tank voraciously eating, the copperband will do the same. Hopefully you can get it eating some of the frozen foods soon. Do write us back in a month or so and let us know if you still think this fish is easy to keep.

From: Jamie S.
I just got a new copperband butterflyfish and it is no problem at all. It has already started to eat the frozen brine shrimp that I feed my other fish and it swims peacefully with the other fish. It has only been in my tank for around 5 hours and is very comfortable in its new tank, so I haven't had any problems so far - will let you know what happens with it.
Five hours is too soon to tell how it's going to go, but if it's eating already that can be a good sign.

From: John
I have had a 100 gallon tank set up for 2 years. No problems with CBB thus far. I got this fish for glass anenome problems. I did not feed the fish and within the first 3 days all tube worms were eaten (about 100) and only after this did the CBB start on the anenomes. There are some problem with an established large sailfin tang pecking on this fish.

From: Grant
I have a ton of aiptasia that I need to get rid of. My tank is a year and a half old 46 gallon with approximately 70 lbs of live rock and about 2 and 1 half inches of live sand. I have a Maroon Clownfish mated with an Ocellaris, a mandarinfish, and a Royal Gramma. Another experienced hobbyist recommended getting a 3-4 inch CBB to help control the aiptasia. I have assorted softies and 2 stalks of leather coral. Do you think a CBB would do okay if I get it to start eating? The aiptasia are very established and would probably be an almost constant food source. And if it picks at my Xenia, it's okay, because I have a lot anyways, as long as it doesnt wipe it out.
While they may go after the aiptasia there are other ways to rid your tank of this pest. Please read the previously linked article on aiptasia for more ideas on how to get rid of it. If you do decide to get a copperbanded butterfly, watch for picking at coral and signs of disease. Like many saltwater species, a period of time in a quarantine tank before introducing into your main display tank is needed for this fish as well.

From: Steve
I wish I read all this before I got my copperband butterfly. I've had him for 3 days so far and he is a beautiful fish and seems to feel himself like at home in my tank, but doesn't seem to care about any foods I offer. He started picking at filter worms immediately, but that's all he is interested in so far. I wonder if he'll ever start eating anything else. I think the ones that eat frozen foods right away must have been in a fish store for a while and got used to it. Getting worried that after the filter worms are gone he might starve to death. Wish me luck on this one.

From: Julia
A comment for Grant. I have 3 peppermint shrimp that ate all of my aiptasia in a few days. You probably don't need a copperband to get rid of those.

From: Justin74
After buying a few that did not make it, and conversing with others and now have kept 2 over a year each(first one died due to power outage. I find the odds are much better when purchasing one that is at the very minimum 3". Any smaller and the odds are really stacked against you, and ultimately them. I speculate it may have something to do with an undeveloped pallet. However both have defintately been nothing but short of finicky. The only prepared food mine will eat is mysis shrimp. And only peck at flake or brine, and dont give pellets even a glance. Both have been model citizens in my reef and with my RBTA and Derasa clam. Although some have experienced different, in that regard they can be a flip of the coin!

From: Kenneth
I've had mine in QT for 2 weeks and is doing great! The first week I couldn't get him to eat anything, but then I tried some frozen blood worms and he started picking at them a little but once they settled to the bottom he wouldn't mess with them. One day of that, and the next day when I put them in he ate them all before they hit the bottom. As long as they moved as if they were alive he wanted them, but if they stopped moving he didn't care so much. Now after 2 weeks he will eat blood worms, a little brine shrimp, and some flake food. No pellets yet, but will chomp on any aptasia I put in there so I'm sure he will clean up my display as soon as I put him in there.
Very cool and excellent job putting them in QT first. Makes it easier to experiment with foods and provides a place for them to settle down from being transported without getting harassed from tank mates and adapt to aquarium life. It can be quite difficult to get them eating. It is also a good idea to ask to see them eat in the dealer's tank before you purchase them. They should go after mysis, brine, rod's food, or similar.

From: Richard - Aiptasia control
My wife and I purchased a CBB for Aiptasia control 3 weeks ago. We have a two year old 55 gallon reef with 2 Maroon Clowns, 3 Bengaii Cardinals, a Lawnmower Blenny and various crabs and snails. My tank was overrun with aiptasia that came in on a frag that I just didn't jump on quick enough. Asked what the life expectancy of a CBB was, one of the employees at the reef shop cynically told us "about 4 days after you run out of Aiptasia". It took the fish to start eating, though he seemed comfortable enough in the tank. It took about a week for the CBB to eat all the Aiptasia in the tank. He also had a parasite of some kind in his gills that was causing him to scrape on rocks an swim around looking irritated. My wife ran out and got a cleaner shrimp, and the problem was gone in a day (we'd been meaning to replace our old one anyway, cleaner shrimp). The Butterfly also ate all of our featherdusters and fanworms, but that's a small price to pay I guess. Now there hasn't been an Aiptasia to be found for a solid week and I was worried he would either starve or go after the Xenia. So far he had ignored the frozen stuff and the flake that we normally feed the tank with. Yesterday he finally nibbled at some Mysis along with the other fish, and today he showed a healthy appetite with more of the same. We will start introducing other foods, and hopefully we can keep it healthy. I'm pretty happy with this fish, it has a great personality, flits around scanning the rocks and substrate, not hyper but active for sure, gets along fine with other non-aggressive fish, and is relatively reef safe.
Yep, aiptasia can reach plague proportions quickly in nutrient rich tanks. Glad to hear it's done a good job for you. Also, +1 on picking up the cleaner shrimp too. I keep at least one in any tank with any of my more prized/expensive saltwater fish. They do way better than any medicinal control hands down in my opinion. If you can't get some some live meaty foods (feeder shrimp, brine, etc) then do try the frozen marine foods to keep the Copperband eating. Good luck with your fish!