Two-colored Angelfish, Blue and Gold Angel, Oriole AngelfishFamily: PomacanthidaeCentropyge bicolorPhoto © Animal-World: Courtesy Greg Rothschild
The flashy Bicolor Angel is a dwarf angelfish with vibrant yellows and blues!
The Bicolor Angelfish Centropyge bicolor is one of the most easily recognized fish. Its bright yellow front half contrasting with the deep royal blue on its back half, gives it a striking coloration. A number of descriptive common names are used for this dwarf angel, including Two-colored Angelfish, Black and Gold or Blue and Gold Angelfish, Pacific Rock Beauty Angelfish, and the Oriole Angelfish. Oriole comes from the medieval Latin word “oriolus” which basically means “golden".
Although the Bicolor Angelfish is a very popular fish it is not necessarily a good angelfish for a reef aquarium. Out of all the dwarf angelfish the Bicolor is the least reef friendly. Getting a juvenile is your best bet, as they are ready eaters and can be more easily trained to aquarium fare. Larger specimens may tend to only feed some on algae, often preferring corals, large polyped corals, tunicates, sponges, and worms, and may nip the mantles of clams. Yet this angel makes up for its lack of coral compatibility with its brilliant coloration. It is a great addition for a "fish only with live rock" aquarium (FOWLR).
This is a good sized dwarf angelfish, reaching up to 5.9 inches (15 cm). This fish is not as easy to keep as many other angelfish. In its captive history, even advanced aquarists couldn't keep the Bicolor Angel beyond an acclimation period. But today, with more net catching methods being employed in collection, this beauty is now considered much easier to keep in captive systems.
A decent sized tank, at least 55-60 gallons, with algae growing on live rock is recommended. Make sure they are offered lots of hiding places and a diet which includes vegetable matter, small crustaceans, and worms. They are aggressive for a dwarf angelfish, especially in a tank under 75 gallons. Keeping with more semi-aggressive to aggressive fish would also be advisable.
For more Information on keeping saltwater fish see:
Marine Aquarium Basics: Guide to a Healthy Saltwater Aquarium
- Size of fish - inches: 5.9 inches (14.99 cm)
- Aquarium Hardiness: Moderately Difficult
- Range ph: 8.0-8.4
- Diet Type: Omnivore
- Minimum Tank Size: 55 gal (208 L)
- Temperature: 73.0 to 82.0° F (22.8 to 27.8° C)
- Temperament: Aggressive
The Bicolor Angelfish Centropyge bicolor was described by Bloch in 1787. Their range includes most of the Pacific ocean excluding Hawaii. They are found in the Indo-Pacific from East Africa to the Soamoan and Phoenix Island then up to southern Japan. They also range from southern Japan down to New Caledonia, including The Great Barrier Reef and all though Micronesia. This species is on the IUCN Red List as Least Concern (LC). This dwarf angelfish has a large population and wide distribution. Although they are harvested for the pet industry there are no major threats currently identified.
There are several common names that mostly describe the various color variations that are found in this dwarf, such as Black and Gold Angelfish, Blue and Gold Angelfish, Two-colored Angelfish, and the Pacific Rock Beauty Angelfish. The other common name, Oriole Angelfish or Oriole Dwarf Angel, comes from the medieval Latin word "oriolus" which basically means "golden." The Oriole is also the name of a bird that is black and orange or yellow.
Bicolor Angelfish range in depths between 3 to 80 feet (1- 25 m). Juveniles are seen at depths of 3 feet (1 m), while adults are generally at least 10 meters (33 ft.) deep. They are found in singly, in pairs, or in small groups inhabiting areas that have lots of hiding places, often going from one hiding place to the next. The can be found in protected seaward reef slopes, drop offs, rubble and coral areas, as well as lagoons and channels. They feed on worms, small crustaceans, benthic algae and weeds, hard coral polyps, sponges, and tunicates.
- Scientific Name: Centropyge bicolor
- Social Grouping: Varies - They occur singly, in pairs, or in harems. Harems range in size with one male having one to 7 adult females, and may have up to 9 immature females.
- IUCN Red List: LC - Least Concern
The Bicolor Angelfish have a slightly longer oval shape than other dwarf angelfish. These are one of the larger dwarf angelfish. They grow to a total length of about 6" (15 cm), which exceeds the length of other species by about 2". The have an average lifespan of about 12 years in the aquarium, though with proper care they could live for up to around 15 years.
They are commonly referred to as the Two-colored Angelfish because the front 1/3 of their body is yellow to gold and the back 2/3 is dark to royal blue. There's is a blue "mask" that runs over the forehead to the top of each eye. At times this fish can have a more "dusky" look to yellow in the facial area. The pectoral, pelvic and tail fins are yellow with the dorsal and anal fins being blue and coming to a point at the ends. Juveniles look similar, except there are darker bars in the blue area.
- Size of fish - inches: 5.9 inches (14.99 cm) - Small juveniles adjust easier to captivity and will eat a wider range of foods.
- Lifespan: 12 years - An average lifespan is 12 years, but they may live up to 15 years with good care.
The Bicolor Angelfish is moderately difficult to keep, but with proper care they could be put at the intermediate aquarist level. They are probably one of the most aggressive dwarf angelfish, so choose tank mates wisely. Obtaining a small juvenile will result in higher success since they will accept a wider variety of foods.
Two-colored Angelfish were considered difficult to keep in the past due to use of cyanide poisoning to capture them. Now netting methods are used to capture these fish, thus enabling a greater success in captivity. While the Bicolor Angelfish is not as "algae" needy as other dwarfs, they still need live rock with algae. Although they are 2" longer than other dwarfs, their tank size can stick to the same 55-60 gallons, since their adult personality will lend itself to eating more "meaty" foods as well as other varieties of flake with spirulina and sponge material
- Aquarium Hardiness: Moderately Difficult - They do best with live rock arranged in a manner that provides lots of hiding places and naturally growing algal foods.
- Aquarist Experience Level: Intermediate
Though an omnivore, the Bicolor Angelfish will eat more "meaty" foods than other dwarf angelfish. They will eat some algae, say about 30% but as they get older they will feed on any corals, worms, sponges or corals you have. It is important that you feed angelfish varieties of live, frozen, and prepared formula foods. Feeding them good prepared foods with spirulina algae, along with mysis, finely shaved fresh or frozen shrimp and angelfish food that has sponge material included. There are several good commercial foods available including Formula II and Angel Formula.
- Diet Type: Omnivore - Offer a diet with Spirulina algae and sponge material included.
- Flake Food: Yes
- Tablet Pellet: Occasionally
- Live foods (fishes, shrimps, worms): Some of Diet - Live foods are not necessary, but are appreciated.
- Vegetable Food: Some of Diet - Vegetable matter makes up about 30% of their diet. Juveniles eat more algae than adults. As adults they will eat closer to 20% algae, so feed according to age.
- Meaty Food: Most of Diet - Protein foods make up about 70% of their diet as adults, and a bit less when they are juveniles
- Feeding Frequency: Several feedings per day - Feedings depend on the size of the tank. Generally they should be fed 2 to 3 times a day, with less in a tank with a lot of natural algae sources. However, if it is a larger tank with more algae for them to forage from, then feed 1 to 2 times day.
The Bicolor Angelfish is moderately difficult to keep. Water quality and size are important. As with all angelfish, keeping pH to a 8.0 minimum is also very important. They are not as forgiving in water quality, as say a clownfish, so doing water changes to match your particular tanks inhabitants are important. If the tank is 55 to 60 gallons, a bi-weekly change of 10% to 15% would be good. If your tank is over 100 gallons, maybe every 3 weeks to a month do a 20% change, and so on.
- Water Changes: Bi-weekly - A 10% to 15% water change bi-weekly to keep water clean is suggested unless tank is over 100 gallons, then 20% every 3 weeks to a month.
The tank needs to be at least 55 gallons for this dwarf angelfish. A tank that is longer, rather than taller is needed due to them swimming near the bottom most of the time. Nano tanks are out, not even when they are young. If keeping a mated pair then 75 to 100 gallons would be appropriate, and over 150 for 2 fish that are unsexed. Provide water parameters of: 73-82° F, pH 8.0-8.4, sg 1.023-1.025.
Providing live rock with plenty of hiding places, especially near the bottom of the tank is helpful to keeping them happy. The live rock that should having algae growing on it before you purchase your Bicolor Angelfish. Try to have your tank up and running for at least 6 months before considering a dwarf angelfish. Add dwarf angels to the tank at the same time and as last additions.
- Minimum Tank Size: 55 gal (208 L) - 55 gallons or more is recommended. Although larger than other dwarf angels, the Bicolor does not need as much algae, thus a similar tank size to a typical dwarf is acceptable.
- Suitable for Nano Tank: No
- Live Rock Requirement: Typical Plus Hiding Places - Hiding places are key to helping dwarf angelfish feel secure. A good amount of live rock to supply natural foods is also important.
- Substrate Type: Any - All dwarf angelfish seem to appreciate a small area of the tank with rubble on which to forage for algae and other edibles.
- Lighting Needs: Any - Lighting should be strong enough to support algae growth. If tank has low lighting, making sure direct sunlight hits the tank to support this natural food is suggested
- Temperature: 73.0 to 82.0° F (22.8 to 27.8° C)
- Breeding Temperature: 77.0° F - At a temperature of 77° F larvae will hatch in 16 hours after spawning, but it will take longer if the water is cooler.
- Specific gravity: 1.023-1.025 SG - Angelfish in general do not do well under 1.023 for long periods of time.
- Range ph: 8.0-8.4 - Angelfish will deteriorate quickly under 8.0.
- Brackish: No
- Water Movement: Any - They like some areas of strong and weak movement. A weaker movement would be appreciated along the bottom for feeding.
- Water Region: Bottom - They will also inhabit mid level areas of the tank.
The Bicolor Angelfish is probably one if the most aggressive dwarf angelfish, if not the most aggressive. Add them last to any system, and if getting more than one, add two simultaneously. Keeping them in a tank that is closer to 75 gallons is advisable since it will allow them to have their territory without feeling they need to attack everyone that happens to swim by. In a 55 gallon tank they will chase pretty much anything that feels threatened by them.
Peaceful fish, as well as slow moving fish will not work well with them unless, again the tank is much larger than 55 gallons. Even some of the smaller semi-aggressive fish like anthias could be chased for this reason. Be cautious with anthias, since they will hide all the time when they do not feel safe, they will wither and die from starvation. Keep with larger semi-aggressive fish like larger tangs and large fish that will not be bullied, yet not too large that they would eat the Bicolor.
Keeping this fish with other dwarf angelfish should only be done in a much larger tank, an aquarium over 100 gallons and preferably up to 150 gallons. This is due to the aggressive nature of the Bicolor. House them with dwarfs that are different in color, size and shape. Adding the Bicolor last once the others have become established is the best bet. Make sure your tank has lots of algae growing and lots of caves and hiding places formed within the rock, if you are doing a dwarf angelfish tank.
Like all dwarf angelfish, they can be kept with the more toxic corals. They just don't taste so good to the Bicolor Angelfish! These include some soft coral genera from the Leather Coral families such as the Sinularia, Sarcophytom, Cladiella, and Paralemnalia; and one from the Xenia family, the Effatounaria genus. Most people have success with Mushroom Anemones and an anemone well guarded by a pugnacious clownfish can survive in the same tank at times. As for Large Polyped Corals (LPS) and clams, these will usually be nipped at until they close up and eventually starve. Polyps are a crap shoot since a well fed fish will usually not bother them. If you have a huge polyp population of some kind and the fish are not decimating it, then look at it as free food for your dwarf angelfish. Starfish, feather dusters and other fluffily appendaged creatures may be tasted, so monitor them. Snails, crabs and large shrimp are usually okay but are best added before the Bicolor Angelfish.
- Venomous: No
- Temperament: Aggressive - One of the most aggressive Centropyge angelfish.
- Compatible with:
- Same species - conspecifics: Sometimes - A male/Female pair can be kept in a tank over 75 gallons (284 l), or 2 of unknown sex in a tank over 100 gallons (378 l).
- Peaceful fish (gobies, dartfish, assessors, fairy wrasses): Threat
- Semi-Aggressive (anthias, clownfish, dwarf angels): Monitor - They will harass smaller fish like clowns and anthias if kept in a tank that is too small.
- Aggressive (dottybacks, 6-line & 8-line wrasse, damselfish): Safe
- Large Semi-Aggressive (tangs, large angels, large wrasses): Safe
- Large Aggressive, Predatory (lionfish, groupers, soapfish): Monitor - Safe unless the tankmate is large enough to eat the Bicolor Angelfish.
- Slow Swimmers & Eaters (seahorses, pipefish, mandarins): Threat - Angel fish will out compete slow moving fish for food.
- Anemones: Monitor - As long as a pugnacious clownfish is guarding the anemone, it should be okay.
- Mushroom Anemones - Corallimorphs: Monitor - They may eat waste exuding from mushrooms, which is not harmful, just keep an eye on the fish.
- LPS corals: Threat - They may graze on the slime they exude preventing them from opening fully, which can cause eventual death of the coral.
- SPS corals: Monitor - They may graze on the slime they exude preventing them from opening fully, which can cause eventual death of the coral.
- Gorgonians, Sea Fans: Monitor - They may graze on the slime they exude preventing them from opening fully, which can cause eventual death of the coral, but still monitor for individual preferences.
- Leather Corals: Monitor - Safe with most from the Sinularia, Sarcophytom, Cladiella, and Paralemnalia genera, but still monitor for individual preferences.
- Soft Corals (xenias, tree corals): Monitor - Safe with most from the genus Effatounaria, but still monitor for individual preferences.
- Star Polyps, Organ Pipe Coral: Monitor - May pick at appendages of these corals if not well fed.
- Zoanthids - Button Polyps, Sea Mats: Threat
- Sponges, Tunicates: Threat
- Shrimps, Crabs, Snails: Safe - Only the smallest decorative shrimp may be at risk. Large cleaner shrimp should be left alone.
- Starfish: Monitor - May pick at appendages if not well fed.
- Feather Dusters, Bristle Worms, Flatworms: Monitor - May pick at appendages if not well fed.
- Clams, Scallops, Oysters: Threat - They may graze on the slime they exude preventing them from opening fully, which can cause eventual death.
- Copepods, Amphipods, Mini Brittle Stars: Safe - Will not decimate populations as it is not a obligate eater of these foods.
These fish are protogynous, the male and female can actually reverse their sexual orientation within 18 to 20 days. The only distinguishing feature to separate the male and female is that the male forms a dark line through and under the eyes during courtship.
As of yet they have not been bred in captivity. In the wild, the Bicolor Angelfish will reach sexual maturity at 2.4 to 2.7 inches (60 to 69 mm). It has been observed that all Centropyge dwarf angelfish have a similar spawning routine. Centropyge spawning typically consists of the male and female circling each other upon meeting, followed by the male making grunting noises. The male will then swim upwards off the bottom, and hover, tilting his body toward her at a 45 to 90 degree angle.
If she is ready to spawn, the female will join the male and both will soar together. When the soaring behavior is complete, this varies between dwarf angelfish species, the male will nuzzle her belly for up to 18 seconds, followed by the male flickering his pectoral fins and opening and closing his mouth. Suddenly, they are belly to belly, releasing gametes, producing fertilized eggs. These eggs are on their own and will not be protected by either parent. The pair will then rush back to the bottom with the male chasing the female for a short time, then moving onto the next receptive female.
- Ease of Breeding: Difficult - The small mouths of the larvae make them very hard to raise in captivity.
Providing a dwarf angelfish with plenty of places to hide and clean water is the best way to prevent illness. Calm fish are healthy fish. If not stressed, they will have a stronger immune system to prevent infections. Like other saltwater angelfish, dwarf angelfish can suffer any disease that captive saltwater environments have to offer. Fish problems can be broken into one of (or a combination of) these types: parasites, bacterial and fungal disease, or physical ailments (wounds and injuries). To learn all about fish problems and find specific answers, see Aquarium Fish Diseases and Treatments.
The best and first defense to prevent diseases is a quarantine period before introducing a new fish. Quarantine tanks should be bare with a PVC tube where the fish can hide. Do regular water changes every day or so. Secondly, fresh water dips can also help to kill anything that is on their body that may spread. PH and temperature must be the same (just use baking soda to bring up the PH if you have soft water but use a test). Start with 5 minutes and up to 15 minutes if they are not showing any signs of distress. This is really only needed if you see anything on their body or if the back fin is starting to fray.
Dwarf angelfish diseases and treatments:
- Parasitic and Protozoan diseases
Dwarf angelfish are prone to parasites like White Spot Disease Cryptocaryon irritans, also known as Marine Ich, Saltwater Ich, or Crypt. Another common disease is Marine Velvet or Velvet Disease Oodinium ocellatum, (syn: Amyloodinium ocellatum or Branchiophilus maris), which is a parasitic skin flagellate. These are two of the most common diseases.
- Symptoms of White Spot Disease are constant scratching and flashing, culminating with numerous white dots all over the body and fins. These dots disappear for a few days, only to return with double the number. This results in the fish suffocating from these parasites blocking the gills from providing oxygen.
- Symptoms of Marine Velvet are a peppery coating giving a yellow to light brown "dust" on body, clamped fins, respiratory distress (breathing hard as seen as frequent or quick gill movements), cloudiness of eyes, glancing off decor or substrate, and possible weight loss.
- Treatment of parasites
For external parasites you can slowly increasing the temperature of your tank to at least 82° F (28° C). That will prevent the parasite from completing its life cycle which includes the attachment to fish. A further combination of the higher temperatures with medicated food will provide timely relief.
Parasites on marine fish kept with live rock or in any type of reef environment can be extremely difficult to treat. Typical treatments like copper and formalin solutions, as well as quinine based drugs are harmful to other marine creatures. However drugs such as metronidazole provide an effective and safe treatment for several protozoan and anaerobic bacterial diseases.
Metronidazole works by ceasing the growth of bacteria and protozoa. Metronidazole is an antibiotic for anaerobic bacteria with anti-protozoal properties. This drug is reef safe, and medications are either added to the water or mixed with the fish food. Some available products that contain metronidazole include Seachem Metronidazole, Seachem AquaZole, Thomas Laboratories' Fish Zole and National Fish Pharmaceutical's Metro-Pro.
The Seachem Metronidazole medications works well in combination with another Seachem product called Focus, which is a bonding agent. This treatment can be used in a reef aquarium since the medication is bound to the food, which even if the corals eat, will not hurt them. Mix Focus in a ratio of 5 to 1 with their Metronidazole (5 parts Focus to one part Metro), then mix this with 1 tablespoon of food. Feed the medicated food to the fish 3 times a day for at least a week or until symptoms are gone.
- Treatment of parasites
- Bacterial Diseases
As with all dwarf angels, they are also vulnerable to bacterial and fungal diseases. Bacterial infections are often a secondary infection resulting from damage caused by a parasitic or protozoan disease. One of concern is the Vibrio bacteria, which starts as an internal infection, turns into Dropsy, Popeye, Bleeding or Red Streaks on the skin. It is a very fast acting bacteria that will kill your angelfish in days. One way it typically starts is with an innocently frayed back fin. This disease will quickly spread and kill a fish within 2 days.
- Treatment of bacterial diseases
Fresh water dips are an important step to kill anything that is on their body that may spread. PH and temperature must be the same (just use baking soda to bring up the PH if you have soft water but use a test). Start with 5 minutes and up to 15 minutes if they are not showing any signs of distress. This is really only needed if you see anything on their body or if the back fin is starting to fray. Only treat in 1/2 doses any medications containing cleated copper as all angelfish are sensitive to this element in it's free form.
For dropsy, popeye, fin/tail rot and septicemia, which are at time secondary infections, another product you can use along with Seachems Metronidazole or alone is Seachems Kanaplex. You still need to use Focus to bond the Kanaplex to the food. Kanaplex, when used with Metronidazole in the same food, would be 2 scoops of Focus, 1 scoop of Kanaplex and 1 scoop of Metronidazole, yet this combination should only be fed once a day for 7 days, since Kanaplex should only be used for 7 days maximum. If you need to continue past 7 days, use only Metronidazole in a separate mixture for further treatment. This product can also be added to the water (without focus) if the fish is not eating.
- Treatment of bacterial diseases
- Physical Ailments
Physical Ailments are often the result of the environment, either water conditions or incompatible tankmates. Poor quality water conditions can lead to fish gasping, not eating, jumping out of the tank, and more. Dwarf angelfish when very stressed or being picked on will hover in the upper corner of the tank and should be removed if the fish bullying your angelfish is not. Tank mate problems can result in nipped fins and bite wounds..
- Treatment for physical ailments
Look for and remove bully fish.
Products on the market to help include stress relievers like Melafix, Wound Treat, and Bio Bandage.
- Treatment for physical ailments
The Bicolor Angelfish are usually easy to find online and in stores. They are moderately priced. They are also commonly called Two-colored Angelfish, Blue and Gold Angelfish, and Oriole Dwarf Angelfish.
- Animal-World References: Marine and Reef
- Centropyge bicolor Bicolor angelfish, Fishbase
- Centropyge bicolor, IUNC Red List, International Union for Conservation of Nature and Natural Resources
- Scott W. Michael, Angelfishes & Butterflyfishes: Reef Fishes Series , Microcosm Ltd, 2004
- Scott W. Michael, Marine Fishes: 500+ Essential-To-Know Aquarium Species, T.F.H Publications inc., 1999
- Mark Allen, Roger Steene and Gerald R. Allen, A Guide to Angelfishes and Butterflyfishes , Odyssey Publishing, 1998
- Bob Goemans, Centropyge bicolor, Aquarium Library, Saltcorner.com
- Roger Steene, Gerald R. Allen, Hans A. Baensch, Butterfly and Angelfishes of the World, Volume 1, John Wiley & Sons, 1980