Pearlscale Butterflyfish

The Pearlscale Butterflyfish is a fancy fellow with its pearly white scales edged in black!

The Pearlscale Butterflyfish Chaetodon xanthurus is a very pretty fish. It’s moderate in size at about 5 1/2 inches (14 cm) in length but has an eye catching color pattern. Its body has black edged pearly scales that give it a cross-hatched or netted pattern overall. Itis accented with a black eyebar to the front and a bright orange red on the rear. Thus it is known by several other descriptive common names including Yellowtail Butterflyfish, Crosshatch Butterflyfish, Netted Butterflyfish, Orange Butterflyfish, and Crowned Pearlscale Butterflyfish.

This butterflyfish comes from Indonesia and the Philippines,so is also commonly known as the Philippines Chevron Butterflyfish. Despite its striking appearance this species is difficult to distinguish from some of its relatives. As a group these fish are members of the the “xanthurus – species complex”, and they can only be identified if you know where they were collected. The very similar “look alikes” are the popular Mertens ButterflyfishChaetodon mertensii and the Red Sea Chevron Butterflyfish (Red Pearlscale Butterflyfish) Chaetodon paucifasciatus, and they are each identified by where they come from rather than looks.

This butterflyfish is moderately hardy and makes a good choice for an intermediate aquarist with some experience. It needs a good sized aquarium that is well established. A 55 gallon tank is the minimum size for a single fish, and a bigger tank will be needed if you want to keep more than one. Decorate the tank with rocks and/or corals with many hiding places along with plenty of swimming space. It swims freely and usually spends a good deal of its time in the open water, moving in and out of crevices.

These are peaceful fish but they are also often shy. They can be kept in a community tank with other peaceful inhabitants, but shouldn’t be kept with more pugnacious fish or they may refuse to eat. Subdued lighting can help initially in acclimating more timid individuals. After a period of adaptation they usually prove to be sturdy aquarium fish. More than one can be kept if they are introduced to the tank at the same time and they can also be housed with other butterflyfishes.

Keeping this butterflyfish in a reef environment is a judgment call. Many reef-keepers hope to keep it in a mini reef and they can be kept with some of the more noxious soft corals, but like many butterflyfish it can be a coral eater. It is relatively safe with stony corals as long as the reef tank is large, well stocked, and they are provided with a proper and nutritious diet. However it does eat corals in nature and may snack on live polyps, so keep a watchful eye.

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

Habitat: Distribution / Background

The Pearlscale Butterflyfish Chaetodon xanthurus was described by Bleeker in 1857. It is found in Indonesia, the Philippines, and north to the Ryukyu Islands of Japan. This species is on the IUCN Red List as Least Concern (LC). They have a wide distribution and there are no major threats currently identified. Other common names they are known by include Philippines Chevron Butterflyfish, Yellowtail Butterflyfish, Crosshatch Butterflyfish, Netted Butterflyfish, Orange Butterflyfish, Crowned Pearlscale Butterflyfish, Pearlscale Butterfly, Cross-hatch Butterflyfish, Yellow-tailed Butterflyfish, and Pearlyscale Butterflyfish.

This fish is a member of the “xanthurus – species complex”.. This complex is comprised of the Pearlscale Butterflyfish and two other species.They are very similar in appearance yet the regions where each of these fish are found do not generally overlap. The other two are the Red Sea Chevron Butterflyfish (Red Pearlscale Butterflyfish) Chaetodon paucifasciatus and the Mertens ButterflyfishChaetodon mertensii. A fourth member once considered part of this complex is the Madagascar Butterflyfish Chaetodon madagascariensis, but it is now recognized as synonym of Chaetodon mertensii rather than as a distinct species.

These butterflyfish are found at depths between 33 – 164 feet (10 – 50 m). Their natural habitat ranges from clear coastal to outer reef slopes and drop-offs where there are live coral reefs. Juveniles are shy and solitary and will usually be found staying close to sheltered areas. They usually live alone or in pairs and feed on small benthic invertebrates and algae.

• Scientific Name: Chaetodon xanthurus
• Social Grouping: Solitary – They are usually seen alone or in pairs, and juveniles are solitary.
• IUCN Red List: LC – Least Concern

Description

The Pearlscale Butterflyfish has a somewhat elongated, disc shaped body that is laterally compressed and it has a protruding snout tipped with a small mouth. The dorsal fin is continuous and it has a truncated tail fin. This species grows to a length of 5 1/2 inches (14 cm). The lifespan for most of the Chaetodon species is between 5 – 7 years, but sometimes longer with proper care.

The adult C. xanthurus has white scales edged in black over much of its body. This black coloring gives it an overall reticulated pattern, often referred to as cross-hatched or netted,and it enhances each scale with a pearly sheen. The rear of the body and back half of the tail fin are an orangish-yellow, and the base of thetail fin is white

• Size of fish – inches: 5.5 inches (13.97 cm)
• Lifespan: 5 years – The average lifespan of Chaetodon species is between 5 – 7 years, and possibly longer with proper care.

Fish Keeping Difficulty

This fish is medium hard to keep and is suggested for an intermediate aquarist. They are rather shy so shouldn’t be kept with more belligerent fish or they may refuse food. Subdued lighting can help initially in acclimating more timid individuals and offering live foods may help ensure they are feeding well. After a period of adaptation they usually prove to be sturdy aquarium fish.

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

Foods and Feeding

The Pearlscale Butterflyfish are omnivores, in the wild they feed on benthic invertebrates and algae. In the aquarium it is important that you feed a good variety. Offer a vitamin enriched meaty diet, dried flakes, shrimps, tablets and frozen foods of all kinds including Formula I, Formula II, Angel Formula and spirulina. Several sponge based frozen foods are now available and can also be fed to butterflyfish. Japanese Nori will also be favored. Feed it at least twice a day, and if it is a tiny juvenile feed it three to four times everyday.

• Diet Type: Omnivore
• Flake Food: Yes
• Tablet / Pellet: Yes
• Live foods (fishes, shrimps, worms): Some of Diet
• Liquid Foods: Some of Diet
• Vegetable Food: Some of Diet
• Meaty Food: Some of Diet
• Feeding Frequency: Several feedings per day – Offer various foods quite frequently at first. Once acclimated adults need at least 2 feedings a day and juveniles need 3 to 4.

Aquarium Care

Acclimate with subdued lighting initially for more timid individuals and offer live food to help ensure they are feeding. Once adapted no special care or technique is needed to maintain this fish in the aquarium. Frequent water changes are not necessary, rather normal water changes at 10% biweekly or 20% monthly are fine. Sudden massive water changes can cause trouble.

• Water Changes: Bi-weekly – Change 10% biweekly or 20% monthly, avoid sudden massive water changes.

Aquarium Setup

These fish need a lot of space to accommodate their size and to swim, they can reach about 5 1/2 inches in length. A 55 gallon tank is the minimum size for a single fish, and a bigger tank will be needed if you want to keep more than one. The tank should be well decorated with rocks and/or corals with many hiding places.

In a reef environment this fish can be kept with some of the more noxious soft corals. This fish does not have a reputation as a coral eater but it may take polyps of some stony coral species, so it is not strongly recommended for coral-rich reefs. The best success is a large reef that is well stocked and a proper and nutritious diet is provided.

• Minimum Tank Size: 55 gal (208 L)
• Suitable for Nano Tank: No
• Live Rock Requirement: Typical Plus Hiding Places
• Substrate Type: Mix – Sand + Coral
• Lighting Needs: Moderate – normal lighting – It can also be kept under bright light as long as some dark areas are provided.
• Temperature: 72.0 to 81.0° F (22.2 to 27.2&deg C)
• Specific gravity: 1.020-1.025 SG
• Range ph: 8.1-8.4
• Brackish: No
• Water Movement: Weak – Water movement is not a significant factor. It can tolerate a rather strong flow but slow-moving water is recommended.
• Water Region: All – It swims freely and usually spends time in the open water.

Social Behaviors

The Pearlscale Butterflyfish is safest kept in a large fish only (FO) or fishonly with live rock (FOLR) community tank. In a reef it does well with soft corals and may be safe with stony corals. However it may eat coral polyps in nature and could snack on the polyps in the aquarium, so keep a watchful eye.

This butterflyfish is prone to being shy if kept with other more aggressive tankmates, andit may then refuse to eat. More than one individual can be kept if they are introduced to the tank at the same time. They can also be housed with other butterflyfishes.

Smaller, non-aggressive fishes like cardinalfish, gobies, tilefish, sometimes other species butterflyfish, fairy basslets, fairy and flasher wrasses are good candidates as tank mates. Larger and rather territorial angelfish like Pomacanthus and Holacanthus can be kept together with this species. Also other angelfish like members of Centropyge, Apolemichthys, Genicanthus, Chaetodontoplus and Pygoplites also can be good tank mates. Small but very territorial fishes like dottybacks should be avoided. Such fish as basses or scorpionfish, even if they are small enough, should also be avoided.

• Venomous: No
• Temperament: Peaceful
• Compatible with:
  • Same species – conspecifics: Yes – They should be introduced to the tank at the same time.
  • Peaceful fish (gobies, dartfish, assessors, fairy wrasses): Safe
  • Semi-Aggressive (anthias, clownfish, dwarf angels): Monitor – They are prone to being shy if kept with other more aggressive tankmates.
  • Threat
  • Large Semi-Aggressive (tangs, large angels, large wrasses): Monitor
  • Large Aggressive, Predatory (lionfish, groupers, soapfish): Threat
  • Monitor
  • Anemones: Safe
  • Mushroom Anemones – Corallimorphs: Safe
  • LPS corals: Monitor
  • SPS corals: Monitor
  • Gorgonians, Sea Fans: Monitor
  • Leather Corals: Safe
  • Soft Corals (xenias, tree corals): Safe
  • Star Polyps, Organ Pipe Coral: Safe
  • Zoanthids – Button Polyps, Sea Mats: Safe
  • Sponges, Tunicates: Safe
  • Shrimps, Crabs, Snails: Threat
  • Starfish: Monitor
  • Feather Dusters, Bristle Worms, Flatworms: Threat
  • Clams, Scallops, Oysters: Threat
  • Copepods, Amphipods, Mini Brittle Stars: Threat

Sex: Sexual differences

No sexual difference is noted for this species. Butterflyfish species studied up to this time indicate that these fish are gonochoristic, meaning that each fish is either a male or a female and they do not change sex.

Breeding / Reproduction

This species has not been cultivated in captivity. In the wild butterflyfish are pelagic spawners that release many tiny eggs into the planktonic water column where they float with the currents until they hatch. Once hatched the fry are in a post-larval where their body, extending from the head, is covered with large bony plates.

Marine butterflyfish have not reportedly been spawned successfully in captivity. There are however, reports of some success in rearing wild collected larvae of some of the corallivorous butterflyfish. It is hoped these captive reared fish will be adapted to accept aquarium foods, and thus broaden the species selections that can be sustained in captivity. For more information see, Marine Fish Breeding: Butterflyfish.

• Ease of Breeding: Unknown

Fish Diseases

Many of the Chaetodon members are often very colorful and attractive to aquarists. Unfortunately some of them are rather difficult to keep for a long period. Some are exclusively coral eaters, and sometimes they suffer from “ich” (white spot disease) and other infectious diseases. Problems with disease are reduced in a well maintained aquarium. Any additions to a tank can introduce disease, so it’s advisable to properly clean or quarantine anything that you want add to an established tank prior to introduction.

Diseases that marine Butterflyfish are susceptible to include Marine Ich(white spot disease), Marine Velvet, Uronema marinum, and Lymphocystis. Some can be treated successfully with medical care or copper drugs, but some species hate sudden changes of water including PH, temperature, or any drug treatment. In the wild a cleaner wrasse (Labroides sp.) will help them by taking parasites from their bodies, however these wrasses are extremely difficult to sustain in captivity. Alternative fish such as Neon Gobies (Gobiosoma spp.) can help them by providing this cleaning service in the home aquarium.

The Pearlscale Butterflyfish may be sensitive to some drugs. Be sure to observe this fish closely when medicating it, so you can remove it if it shows signs of stress. For information about saltwater fish diseases and illnesses, see Aquarium Fish Diseases and Treatments.

Availability

The Pearlscale Butterflyfish, also called the Philippines Chevron Butterflyfish or Yellowtail Butterflyfish, is available from time to time. It may be found online and sometimes in pet stores and is usually moderately priced.

References

• Animal-World References: Marine and Reef
• Chaetodon xanthurus (Bleeker, 1857) Pearlscale butterflyfish, Fishbase.org
• Chaetodon xanthurus, The IUCN Red List of Threatened Species
• Helmut Debelius, Rudie H. Kuiter, World Atlas of Marine Fishes, Hollywood Import & Export. Inc., 2006
• Scott W. Michael, Angelfishes & Butterflyfishes: Reef Fishes Series , Microcosm Ltd, 2004
• Butterflyfish Compatibility With Corals, Orphek.com, Copyright 2009 – 2012
• Robert M. Fenner, The Conscientious Marine Aquarist: A Commonsense Handbook for Successful Saltwater Hobbyists , TFH Publications, 2001
• Mark Allen, Roger Steene and Gerald R. Allen, A Guide to Angelfishes and Butterflyfishes , Odyssey Publishing, 1998
• Dr. Warren E. Burgess, Dr. Herbert R. Axelrod, Raymond E. Hunziker III, Dr. Burgess’s Atlas of Marine Aquarium Fishes, T.F.H Publications inc., 1990
• Roger Steene, Gerald R. Allen, Hans A. Baensch, Butterfly and Angelfishes of the World, Volume 1, John Wiley & Sons, 1980