A Yellowhead Angelfish will catch your eye not only for its looks, but also for its price!

The Yellowhead Angelfish Centropyge joculator is quite conspicuous because it is beautiful. This attractive dwarf angelfish is a bright yellow on the front half of the body, dark bluish black on the back half, and has a bright yellow tail. That dramatic color pattern is accented with a brilliant blue ring circling the back of the eye and blue edgings ontop and bottom fin. It also stands out because it is a rather pricey novelty and a rare find for the marine aquarist, all of which contribute to making it a very desirable fish.

This dwarf angelfish hails from the Cocos-Keeling Islands and Christmas Island of the southeastern Indian Ocean. It was first collected at Cocos-Keeling in 1974, so it also has the common namesof Coco’s Angelfish and Coco’s Pygmy Angelfish. The names Joculator Angelfish and Joculator Pygmy Angel are in reference to its scientific name. A more recent “pet name†describing captive bred specimens is Jock Angelfish. This dwarf has almost the same color pattern as its relative, the Bicolor AngelfishCentropyge bicolor from the Pacific Ocean. But the Bi-Color has a blue bar on the nape of its head, which is missing on this species, and it lacks the blue ring around the eye. This species is not as readily available as the Bi-Color but is a hardier.

Wild caught specimens reach 3 1/2 inches (9 cm) in length, though captive bred may attain lengths of about 4 1/2 inche. Stilleither size makes them great for the average fish tank. This little fish is a hardy aquarium inhabitant once it is acclimated. It will do much better in captivity than a Bicolor Angelfish for the same look, but the price will knock you off your feet! The Bi-color is a lot bigger, at about 6 inches in length, and a lot cheaper, but has a dismal survival rate in captivity. Once the Bi-color reaches adulthood its dietary needs are hard to meet. Yellowhead Angelfish are being captive bred, but even these are fetching a large sum of hundreds of dollars per specimen! They have been cultivated by Reef Culture Technologies (RCT) in Hawaii, yet even this amazing company has a very hard time culturing them up to a juvenile state, and they are producing only a few per clutch.

This fish is great for an intermediate aquarists who can provide proper housing and tank mates. Wild caught individuals will adapt to aquarium life and food quite readily if provided a tank that has plenty of hiding places. A captive raised specimen is very hardy and will settle easily into its new home. Like all dwarf angelfish, ifit is kept in a tank that is only 30 gallons, it will attack more passive tank mates. Keeping it in a tank of 30 gallons by itself can work, but a 55 gallon (208 l) or more would be safer if you want to keep more fish. They are aggressive towards peaceful passive fish, but in a larger tank they may be okay. Keeping them with the same size or larger semi-aggressive fish is advisable. A male/female pair can be kept in a tank that is at least 75 gallons (283 l).

Being very active it needs plenty of swimming space. It also needs lots of rockwork with many nooks and crannies to dart into. This is important to help them feel secure and avoid stress. Algae is a natural food for them, so light that is bright enough to support algae growth is appreciated as well as a rubble area that collects detritus.

A reef environment is actually ideal for this fish, but as with most of the pygmy angels it may damage some of the stony and soft coral species. They are safe with certain noxious species of soft corals, mushroom anemones, and anemones that are guarded by a clownfish. They will not bother most invertebrates except clams, since they feed of the slime they produce. However one aquarist reported a very well behaved Yellowhead Angelfish that did not bother his clams. They may be attracted toward the feathery appendages of Feather Dusters, Coco Worms, Christmas Tree Rock worms, and similar animals. Overall this is an individual behavior with each fish having its own tendencies, so if you wish to try it in a reef keep a close eye on your corals and other inhabitants to see how your fish will behave.

For more Information on keeping saltwater fish see:
Marine Aquarium Basics: Guide to a Healthy Saltwater Aquarium

Joculator Angelfish Spawning

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Yellowhead Angelfish (Centropyge Joculators) spawning in reef tank.

Awesome video of a male and female Yellowhead Angelfish pair spawning in a full blow reef tank. There are anthias, Ornate Angelfish (Genicanthus sp.), damselfish, and a nosy Long Nose Hawkfish. Very pretty and a great sight to see in captivity!! Accompanied by a rather humorous song.

  • Kingdom: Animalia
  • Phylum: Chordata
  • Class: Actinopterygii
  • Order: Perciformes
  • Family: Pomacanthidae
  • Genus: Centropyge
  • Species: joculator
Yellowhead Angelfish – Quick Aquarium Care
  • Aquarist Experience Level: Intermediate
  • Aquarium Hardiness: Moderately hardy
  • Minimum Tank Size: 30 gal (114 L)
  • Size of fish – inches: 3.5 inches (8.99 cm)
  • Temperament: Semi-aggressive
  • Temperature: 72.0 to 79.0° F (22.2 to 26.1&deg C)
  • Range ph: 8.1-8.4
  • Diet Type: Omnivore
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Habitat: Distribution / Background

The Yellowhead Angelfish Centropyge joculator are found in the Southeastern Indian Ocean at the Cocos-Keeling Islands and Christmas Island. It was discovered and then described within a year of its first collection by Smith-Vaniz and Randall in 1974. They were first collected in the Cocos-Keeling Islands by an expedition from the Philadelphia Academy of Sciences, and later at Christmas Islands by Dr. Gerald Randall and Roger Steene. Smith-Vaniz and Randall also described Colin’s Pygmy AngelfishC. colini collected from the same area at that time.

This species is on the IUCN Red List as Least Concern (LC) because although it has a limited distribution it has a large population. They are collected in limited numbers for the pet industry but there no major threats currently identified. Other common names it is known by are Joculator Pygmy Angel, Coco’s Pygmy Angelfish, Joculator Angelfish, Coco’s Angelfish, and Cocos Islands Pygmy Angelfish. A more recent “pet name†is Jock Angelfish, found online in reference to captive bred specimens

They occur at depths between 26 to 230 feet (8 – 70 m), but are most commonly found at 49 feet (15 m) or deeper. They are found on steep outer reef slopes and drop offs among areas of coral and rubble. The species is abundant in their natural habitat and seen singly or in a small group; harems consist of five to six adults along with a few juveniles. In the wild they feed on benthic weeds and algae, zoobenthos or hard coral polyps, sponges, ascidians (sea squirts), and tunicates.

  • Scientific Name: Centropyge joculator
  • Social Grouping: Varies – Found singly or in harems of five to six individuals along with a few juveniles.
  • IUCN Red List: LC – Least Concern

Description

The Yellowhead Angelfish has the typical shape for a dwarf species with a small elongated oval shaped body, but with more truncated rounded fins than most. Males also have slightly more elongated dorsal and anal fins than females. Reef Culture Technologies (RCT) in Hawaii reports their adults reaching 4.5â€, but most wild caught will be smaller at about 3.5†(9 cm) in length. Their typical lifespan is 6 years but they could live longer with proper care.

This fish is described by its common name ‘yellowhead’, reflecting this bold aspect of its appearance as it reaches full size. The bright yellow to gold area reaches from the snout to about 1/3 of the body, then it abruptly changes to a blackish blue colorwhichis followed by a bright yellow to gold tailfin. There is a blue ring around eye in the shape of a “C†anda little tiny blue spine on the cheek. The pectoral, fins,pelvic fins, and the first three or four dorsal spines are yellow, then the rest of the dorsal and anal fins are blackish blue with blue outer edges. Juveniles at about the age of 125 days, look very similar to the adults except for their size and they have a little eyespot on the back of the dorsal fin.

This dwarf angel looks very similar to the Bicolor Angelfish Centropyge bicolor from the Pacific Ocean. Both have a body color that is yellow in front, a dark bluish black to the back, and a yellow tail. However the Bicolor is much larger, reaching about 6†in length, and has a blue mark on the nape of its head. It lacks the blue ring around the eye seen on the Yellowhead.

This fish is also similar to the juvenile form of its very close relative, the Hotumatua’s Angelfish Centropyge hotumatua. But the Hotumatua’s differs in that it has a prominent blue to black spot just behind the eye, less yellow on the head area, and a deep brown body that lightens to a tannish yellow as an adult.

  • Size of fish – inches: 3.5 inches (8.99 cm) – They are typically 3.5″ (9 cm) in length, though Reef Culture Technologies (RCT) in Hawaii reports their adults reaching 4.5†(11.4 cm).
  • Lifespan: 6 years – Most Centropyge will reach 10 years or more in captivity in proper conditions.

Fish Keeping Difficulty

The Yellowhead Angelfish will be moderately hardy once acclimated and issuggested for an intermediate aquarist. To acclimate this fish when you first acquire it, you need to help it feel secure. Do this by providing multiple hiding places and keep it with a few active, but non-aggressive fish, such as flasher wrasses or chromis damsels. They can entice it to come out and explore, also encouraging it to accept prepared foods. A captive raised specimen is very hardy and will settle easily into its new home.

This fishalso likes a bit warmer aquarium than other dwarf angels, preferring over 81° F (27° C). So If you have a finicky eater try increasing the temperature slightly. Do not let pH drop below 8.0 the nitrates need to be kept low with regular water changes. Any nitrites can be lethal. Once it is successfully acclimatized it will become a very hardy fish.

  • Aquarium Hardiness: Moderately hardy
  • Aquarist Experience Level: Intermediate

Foods and Feeding

The Yellowhead Angelfish is an omnivore. In the wild they feed on benthic weeds, algae, zoobenthos, an other invertebrates. In the aquarium variety is the key. Feed flake, pellet and frozen preparations with sponge material and spirulina, along with enriched brine and mysis shrimp in a freeze dried or frozen form. It does well on naturally growing algae and accumulated detritus in the tank, as a supplemental food source.

There are several good commercial foods available including Formula II and Angel Formula. Adding Selcon, a concentrated nutritional supplement, to the freeze dried variety of foods as it can help deliver vitamins to your dwarf angelfish. Feed frequently at first with various foods, including algae. Once acclimated feed an adult at least twice a day, but for a tiny juvenile provide it with foods three to four times a day.

  • Diet Type: Omnivore – They are an omnivore, leaning more toward algae consumption. Offer a diet with Spirulina algae and sponge material included.
  • Flake Food: Yes
  • Tablet / Pellet: Yes
  • Live foods (fishes, shrimps, worms): Some of Diet – Feed mostly as a treat, but live brine shrimp (gut loaded) and live black worms may help illicit a feeding response in finicky fish.
  • Vegetable Food: Half of Diet
  • Meaty Food: Half of Diet
  • 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.

Aquarium Care

The Yellowhead Angelfish is moderately hardy, but still needs good water. Water quality and tank size are important. The larger the tank, the less often water quality will deteriorate and fewer water changes will need to be done. Keeping up with your water testing will tell you when your tank needs a water change.

Sudden massive water changes can cause trouble. In a 30 gallon (113 l) tank a suggested water change of 5%-10% every week will keep the quality up. If the tank is 55 to 60 gallons, a bi-weekly change of 10% to 15% would be good. If your tank is over 75 gallons, every 3 weeks to a month do a 20% change. A consistent pH level of 8.1 to 8.4 pH is recommended for optimum health.

  • Water Changes: Bi-weekly – A weekly water change of 5-10% is suggested for a 30 gallon tank, but 10-15% bi-weekly for 55 gallons is fine, and about 20% every 3 weeks to a month for tanks over 75 gallons.

Aquarium Setup

This is one of the hardier Centropyge. Keeping it in a tank with plenty of hiding places will help it to adapt easily to captivity,andthey will eventually start eating prepared foods. If keeping in a tank that is only 30 gallons, it is best kept alone. Otherwise, with its aggressive nature it will tend to guard its home against any other fish, especially peaceful fish and other algae eating fish. To house it with other fish the tank should be at least 55 gallons (208 l). A male/female pair should be kept in a tank that is at least 75 gallons (283 l) to provide enough space and natural foods.

As with all angelfish, the tank needs to be mature, at least 6 months old or more to provide plenty of algae growth. They need plenty of places to hide within the live rock, as well as an area that has rubble rock to provide a trap for detritus, which is also a natural food source for them. Enough light to provide natural algae growth is recommended. Tank size has a lot to do with water quality,andthese fisheat a lot so produce a lot of waste. Smaller tanks will need a lot more attention,they will have less stable water quality for this very expensive fish.

  • Minimum Tank Size: 30 gal (114 L) – A 30 gallon tank would only be acceptable if it is the only fish in the tank. 55 gallons (208 l) or more would be needed with other fish, and a male/female pair need at least 75 gallons.
  • Suitable for Nano Tank: No
  • Live Rock Requirement: Typical Plus Hiding Places – Hiding places are key to helping dwarf angelfish feel secure, and a good amount of live rock to supply natural foods is also important.
  • Substrate Type: Any – An area of rubble to hold detritus, which is a natural food source, is advisable. Clean area as needed during water changes.
  • Lighting Needs: Any – Providing enough light to promote algae growth is advisable.
  • Temperature: 72.0 to 79.0° F (22.2 to 26.1&deg C)
  • Specific gravity: 1.023-1.025 SG – Angelfish in general do not do well under 1.023 for long periods of time.
  • Range ph: 8.1-8.4 – Angelfish will deteriorate when pH levels are under 8.0 for extended periods of time.
  • Brackish: No
  • Water Movement: Any – While they enjoy brisk water movement, they like a calmer area with a lower flow in areas where they graze.
  • Water Region: Bottom – Will swim in mid areas of the tank when comfortable.

Social Behaviors

The Yellowhead Angelfish is recommended for fish only tanks, as well as select reef aquariums. They are more aggressive than most dwarf angelfish. If you want to keep it with other fish the tank should be at least 55 gallons. A male and female pair can be kept in a tank that is at least 75 gallons (283 l) or more with several hiding places. Do not keep with similar colored fish such as the Bicolor Angelfish.

Yellowhead Angelfish juvenile, Coco's Pygmy Angelfish
Yellowhead Angelfish (Juvenile) Photo © Animal-World: Courtesy Hiroyuki Tanaka

It is an active fish and can get along together with more aggressive species such as triggers, large wrasses, and larger and rather territorial angelfish like Pomacanthus and Holacanthus. Other angelfish such as members of Centropyge, Apolemichthys, Genicanthus, Chaetodontoplus and Pygoplites could be good tank mates in larger tanks over 75 gallons (283 l).

They have been known to chase after tangs and damselfish that are indigenous to the area they are found in, quite possibly to keep them away from their food source. Keeping with smaller cardinalfish, gobies, tilefish, butterflyfish, fairy basslets, fairy and flasher wrasses, needs to be monitored. Their aggression toward these more peaceful fish will be heightened in smaller tanks, under 55 gallons. Adding this dwarf angelfish after these more peaceful fish in a larger tank may be successful. Small but very territorial fishes like dottybacks should be monitored unless in very large tanks, but with the high cost of the Yellowhead Angelfish, it would be wise to just say no.

As with most dwarf angelfish, exercise caution when adding them to a reef tank. If they are well fed, they should leave most corals alone. Noxious soft corals, mushroom corals, and an anemone with a clownfish guarding it should all do well. If you want to try stony corals just keep an eye on them and be ready to remove any that your Yellowhead Angelfish decides will make a great lunch. The behavior of each individual fish will be different. If you do want to keep it in a reef observe its behavior towards the corals closely, removing it to a fish only tank if it tends to pick at them for any length of time.

  • Venomous: No
  • Temperament: Semi-aggressive – Probably one of the more aggressive of the semi-aggressive dwarf angelfish.
  • Compatible with:
    • Same species – conspecifics: Sometimes – A known male and female pair in a tank that is at least 75 gallons (283 l).
    • Peaceful fish (gobies, dartfish, assessors, fairy wrasses): Monitor – Will attack peaceful fish in tanks under 55 gallons.
    • Semi-Aggressive (anthias, clownfish, dwarf angels): Monitor – Will attack similar sized fish in tanks under 55 gallons (208 l).
    • Monitor – Although in larger tanks the Yellowhead Angelfish may do fine with these fish, any risk to this expensive fish may be something to rule out.
    • Large Semi-Aggressive (tangs, large angels, large wrasses): Safe
    • Large Aggressive, Predatory (lionfish, groupers, soapfish): Monitor – Safe unless the fish is large enough to eat your dwarf angelfish.
    • 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 – May eat waste exuding from mushrooms, keep an eye on the fish.
    • LPS corals: Monitor – May eat the slime layer that some LPS produce, so watch coral for signs of staying closed.
    • SPS corals: Monitor – May eat the slime that some SPS produce, so watch coral for signs of staying closed.
    • Gorgonians, Sea Fans: Monitor – May nip at tentacles watch coral for signs of staying closed.
    • Leather Corals: Safe – 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 nip at tentacles watch coral for signs of staying closed.
    • Zoanthids – Button Polyps, Sea Mats: Monitor – May nip at polyps if not well fed.
    • Sponges, Tunicates: Threat
    • Shrimps, Crabs, Snails: Safe
    • Starfish: Monitor – May nip at food the starfish has in its tentacles if not well fed
    • Feather Dusters, Bristle Worms, Flatworms: Monitor – May nip at feathery appendages if not well fed.
    • Clams, Scallops, Oysters: Monitor – Some have stated success with clams, but keep an eye out for clam not staying open and feeding.
    • Copepods, Amphipods, Mini Brittle Stars: Safe – Will not decimate populations as it is not a obligate eater of these foods.

Sex: Sexual differences

No sexual difference in color is noted, but males are larger than females and the dorsal and anal fins are elongate on males than on females.

Breeding / Reproduction

The Yellowhead Angelfish has been cultivated at Reef Culture Technologies (RCT) in Hawaii in April of 2006. The report shows that their breeding pairs were producing large fertile spawns, and the larvae had a good survival number up to the settlement stage. The problem arose during the long process between the time of the larvae settling to the metamorphosis to the juvenile stage. During this time, which was taking over 50 days, they died off until there were only a few individuals that came through to the juvenile stage. It seems that the longer the period between settlement and complete metamorphosis, the higher the mortality rate.

In their natural habitat, the pygmy angelfish form a harem dominated by one large male with between one and five smaller mature females and up to nine juveniles. At dusk during the lunar month the male will conduct an elaborate mating ritual and then spawn with each of the females individually. Each female gets a turn with the male to rise up several feet above the reef and release the eggs and sperm together directly into the water column. The eggs are fertilized and continue to rise up to the plankton rich surface. For more information see Marine Fish Breeding.

  • Ease of Breeding: Difficult – Has been bred in captivity, though very difficult.

Fish Diseases

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:

  1. 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.
  2. 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.
  3. 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.

Availability

The Yellowhead Angelfish is rarely available at retailers, but at times can be found online for a very high price, currently in the hundreds of dollars range.

References