Beauty and brawn! The Purple Tang as beautiful as it is hardy, and quite mellow if given the proper tank size!
Probably one of the most recognizable fish, the Purple Tang has a bluish purple body that almost glows when well fed! They also have a yellow tail fin and yellow on the tips of their pectoral fins. Their long snout allows them to get in between crevices and cracks. When their dorsal and anal fins are extended, they are as tall as they are long! The male Purple Tang grows to 9.8,” and tangs grow to 80% of their total length within the first 4 to 5 years, then grow slowly after that. These tangs live from 30 to 45 years (Choat and Axe 1996). This tang is best left to intermediate aquarists due to the need for a very large tank and proper water parameters.
These beautiful tangs come from the Red Sea, which is a gulf. This is significant because gulfs have fluctuating salinity due to evaporation. This makes the Purple Tang pretty durable and is not bothered with slight variations in salinity. With that in mind, the salinity in the tank should be 1.023 to 1.025 for optimal color and health. They are not a beginner fish, however and still need good water quality. Purple Tangs look the most similar to the Yellow Tang, which is yellow all over.
Once acclimated, the Purple Tang is very hardy and disease resistant. It is also fairly easy to maintain with proper feeding and good water quality. However it is also rather rare and expensive. Choose juveniles since adults take more dedication to acclimate. This excellent prize is best for an experienced aquarist with deep pockets. Like all seven of the Zebrasoma species, though quite robust it has a tendency to develop Lateral Line Disease (LLD) if tank conditions or diet are neglected.
This semi-aggressive tang can be a good community fish, however it does get territorial and can be aggressive to new additions to the tank as it gets older. Keep it singly as it does not mix with others of the same genus in captivity unless the tank is hundreds of gallons. Purple Tangs need good nutrition along with lots of water movement to provide plenty of oxygen, good filtration, and regular water changes. It is also good at nibbling algae so can be asset in a reef environment, but this species has been known to nip at some of the large polyp stony corals and low growing soft corals like zoanthids, star polyps and some gorgonians. The bottom line, keep a sharp eye on its environment, diet, and behavior.
The Purple Tang is a good sized agile fish so will need plenty of space for swimming. They need a minimum tank length of 6 feet once they are adults, which translates to a minimum tank size of 125 gallons. They may be kept in a 75 gallon tank until they are 4 to 5,” and then should be moved promptly before they start to develop a bad attitude! There are some things that the Zebrasoma species have in common with all the surgeonfishes and tangs. They like plenty of water movement to provide an oxygen rich environment rather than a placid aquarium. They are quick and agile swimmers so will need lots of swimming space along with plenty of crevices among corals/ rocks to retreat into and for sleeping at night.
For more Information on keeping marine fish see:
Guide to a Happy, Healthy Marine Aquarium
- Kingdom: Animalia
- Phylum: Chordata
- Class: Actinopterygii
- Order: Perciformes
- Family: Acanthuridae
- Genus: Zebrasoma
- Species: xanthurum
- Aquarist Experience Level: Intermediate
- Aquarium Hardiness: Very Hardy
- Minimum Tank Size: 125 gal (473 L)
- Size of fish – inches: 9.8 inches (24.89 cm)
- Temperament: Semi-aggressive
- Temperature: 72.0 to 78.0° F (22.2 to 25.6° C)
- Range ph: 8.1-8.4
- Diet Type: Herbivore
- My Aquarium – Enter your aquarium to see if this fish is compatible!
Habitat: Distribution / Background
The Purple Tang or Yellowtail Tang, Zebrasoma xanthurum was described by Blyth, in 1852. The genus Zebrasoma means “horse body,” which comes from the word Zebra or horse in African and soma or body in Greek. The common names refer to it’s coloring, body type (sailfin) or location and they are: Purple Tang, Red Sea Sailfin, Yellow Tang, Yellowtail Sailfin Tang, Yellowtail Surgeonfish, and Yellowtail Tang.
They are found in the in the Red Sea and the Arabian Peninsula to the Persian Gulf. Purple Tangs live in rubble reefs and coral-rich areas. They are found more often on the outer islands of the Gulf of Oman and the Arabian Sea. In their natural habitat they are found at depths between 7 to 65 feet (2 – 20 meters) feeding on filamentous algae. Adults are at times found alone or in pairs and schools as they feed during the day. Juveniles are solitary and very secretive, dwelling among corals.
The Purple Tang is on the IUCN Red List for Endangered Species, listed under Least Concerned with a stable population trend.
- Scopas or Twotone Tang, Zebrasoma Scopas: This brown tang has a shorter mouth, however they have been known to interbreed with each other..
- Yellow Tang , Z. flavescens: This all yellow tang also has the same shape and has a white peduncle spine. These two species interbreed.
- Black Longnose Sailfin Tang, Zebrasoma rostratum: This black tang has a slightly longer mouth, however they have been known to interbreed with each other, and it is black, not dark brown.
- Scientific Name: Zebrasoma xanthurum
- Social Grouping: Varies – Adults: Solitary, pairs, small schools Juveniles: Solitary
- IUCN Red List: LC – Least Concern
The Purple Tang has a disk like shaped body similar to all surgeonfish, but with giant dorsal and anal fins. When the fins of the sailfin tangs are fully extended, the height of these fish is about the same as the length. Like all the sailfin tangs, the Purple Tangs have a slightly extended snout. True to their name, the body is a beautiful dark blue to purple and the caudal fin is a bright yellow. There are black spots on the head and the front portion of the body extending onto the adjacent fins, and black scribbly horizontal lines on the rest of the body and fins with the exception of the caudal fin. There is also a yellow accent on the edge of the pectoral fins.
On each side of the caudal peduncle is a single spine or “scalpel” used for defense or dominance. When not in use the spine is folded down into a groove. Caution needs to be exercised when handling surgeonfish as a cut from its scalpel can cause discoloration and swelling of the skin with a high risk of infection. The pain lasts for hours then still ends up having a dull ache. They grow up to 9.8″ (25 cm), and will reach 80% of that length or 7.8″ within the first 4 years of life, then grow much slower after that. Zebrasoma can live up to 45 years or more (Choate and Axe, 1996).
- Size of fish – inches: 9.8 inches (24.89 cm)
- Lifespan: 45 years – 30 to 45 years (Choat and Axe 1996), possibly less in captivity.
Fish Keeping Difficulty
The Purple Tang is a great addition to the marine aquarium and fairly easy to keep if its diet and environment are well maintained. The Rea Sea, where these fish are found have more evaporation than the large oceans so they can handle some fluctuations in salinity, but the salinity should be 1.023 minimum. They do well in an environment that has consistent water, quality, temperature, decor and fellow tank mates. It can be housed in a fish only tank or in a reef environment, but on occasion they have been known to nip various corals/inverts. (See Social Behaviors) Provide plenty of space, especially for adult specimens, along with lots of rocks/ corals with crevices for retreating, feeding from and for sleeping. All surgeonfish need an aquarium with plenty of aeration, a strong current will help to provide good oxygenation.
Surgeonfish and tangs are continuous feeders and they need to be provided a proper diet. They are susceptible to nutritional disorders which may cause color loss and LLD (lateral line disease) and bacterial infections resulting from poor water quality. Consequently they will need vigorous filtration, protein skimming, and regular small water changes. Tangs do not produce as much skin mucus on their bodies as other fish and can be susceptible to diseases such as Marine Ich and Marine Velvet. Surgeonfish are definitely a candidate for quarantine when you first receive them. (See Diseases)
- Aquarium Hardiness: Very Hardy
- Aquarist Experience Level: Intermediate – Due to expense and specific needs of this fish.
Foods and Feeding
The Zebrasoma genus are primarily herbivores. In the wild, Purple Tangs feed almost exclusively on filamentous algae which they scrape from hard surfaces. Stomach contents on fishbase.org only reveal algae and nothing else. This genus can store fat in their body cavities so may go through periods of non-feeding.
In the aquarium the majority of their intake will be vegetable matter, and they will eat some copepods living within the algae they eat, but they do not need meaty foods as a main meal. Provide lots of marine algae, prepared frozen formulas containing algae or spirulina, frozen brine and mysid shrimp, and flake foods. Japanese Nori or other seaweed can be adhered to the aquarium glass with a vegetable clip. An occasional live rock with micro and macro organisms will be greatly appreciated. Culturing macro algae like chaetomorphia in the tank is also a great idea. Feed 3 times a day in smaller amounts instead of a large quantity once a day. As continuous grazers, they will benefit from this and it will also keep the water quality higher over a longer period of time.
Having an extra tank to grow macro algae is the best option for free food!
- Diet Type: Herbivore
- Tablet / Pellet: Yes
- Live foods (fishes, shrimps, worms): Some of Diet
- Vegetable Food: All of Diet – Natural marine sources are best, such as macro algae and even Nori sheets used to wrap sushi.
- Feeding Frequency: Several feedings per day
A quick and agile swimmer it will spend a good deal of its time in the open water and moving in and out of crevices.
-Medium sized up to 90 gallons, perform 15% bi-weekly.
-Large Tanks 100 gallons and over, once water is aged and stable can be changed 10% bi-weekly to 20% monthly, depending on bioload.
Fish only tanks:*
-Medium sized up to 90 gallons, perform 20% to 30% monthly depending on bioload.
-Large Tanks 100 gallons and over, once water is aged and stable can be changed 20% to 30% every 6 weeks depending on bioload.
For more information on maintaining a saltwater aquarium see: Saltwater Aquarium Basics: Maintenance. A reef tank will require specialized filtration and lighting equipment. Regular water changes done bi-weekly will help replace the trace elements that the fish and corals use up.
*Note: If this is the ONLY fish in the tank, with no corals or other fish you can get away 20% monthly.
- Water Changes: Bi-weekly
Your active Purple Tang needs a minimum tank size of 125 gallons as an adult, which is the smallest commercial 6 foot long tank. Juveniles should be okay is a 4′ tank that in at least 75 gallons, however they should be moved to the larger tank once they are 4-5″ long. To feel secure they also need rocks/ corals with many nooks and crannies to hide in and to wedge themselves into at night for sleeping. This fish may bother some corals and inverts if it is not fed well. It will mainly graze on algae if it is available. Keep corals glued down, as their quick speeds may topple a coral or two. Because they thrive well in tanks with algae growth, the tank should be mature and if it is a fish only tank, provide lighting to help algae growth. The temperature they prefer is 72 to 78˚F (22 to 26˚C), normal ocean salinity of at least 1.023, and a pH that is 8.1 to 8.4. All of these parameters should be stable and should not fluctuate. Provide an area of strong linear water flow for them to swim against and be sure the water quality stays high. They are found on all levels of the tank. Tangs produce a lot of waste, so the larger the tank, the easier it is to keep clean. A strong skimmer and good filtration is recommended for long term health.
- Minimum Tank Size: 125 gal (473 L) – Six feet long minimum
- Suitable for Nano Tank: No
- Live Rock Requirement: Typical Plus Hiding Places
- Substrate Type: Any
- Lighting Needs: Moderate – normal lighting – Enough to promote algae growth.
- Temperature: 72.0 to 78.0° F (22.2 to 25.6° C)
- Breeding Temperature: – Unknown
- Specific gravity: 1.023-1.025 SG – Coming from the Red Sea, salinity can be higher than 1.023
- Range ph: 8.1-8.4
- Brackish: No
- Water Movement: Strong
- Water Region: All
Purple Tangs are about a 6 on the scale of 1 to 10, with 10 being the most aggressive for the Zebrasoma genus. While they are listed as more aggressive, they do not bother other fish, unless they are eating the same foods. There should only be one per tank, and no others from this genus.
If you wish to house them with other tangs, choose those who eat different foods. For example, those from the Bristletooth group like the Yelloweyed Kole Tang, is a perfect complimentary tang to add if the tank is over 100 gallons and the Bristletooth is added first. You may also pair this tang with different genus’ as long as there are no similarities. One example of mixing genus in a very large tank, over 300 gallons without incident would be to house a Naso Tang, Yelloweyed Kole Tang, and a Hippo Tang. Adding them together as juveniles best, rather than adding a new one later on. Though a large aquarium can help alleviate many problems, be aware of the social behaviors of any species you are considering to prevent compatibility problems. Adding a tang to a tank that already has tangs that have staked out there territory can cause problems, however, rearranging rock work can help alleviate the stress. There will be aggression towards the new tang, so keep an eye on their behavior and remove them if they are constantly hiding or up in the corner of the tank.
Purple Tangs do get cantankerous with age, sometimes they start bullying other non-tang fish, and they can be intolerant of new additions to the tank. When it comes to other fish, Purple Tangs are usually fine while young, although a fish that is not a tang but has a similar palate for filamentous algae may get picked on as the tang “guards” his crop of algae. Avoid triggers, puffers, and other aggressive fish which can stress your Purple Tang out. If your tang is “posturing” and using his scalpel to whack a tank mate, then remove that tank mate or the tang.
The great thing about the Purple Tang is that they will graze on various algae, so can be an asset to a reef environment. The downside is that have been known to nip on large polyp stony corals. They have been known to occasionally go after star polyps, gorgonians, and zooanthids.
Some inverts are also at risk. Zebrasoma have been known to pick on the mantels of clams. They have been known to eat very small fan worms and have accidentally chewed through the tubes of Feather Dusters that had algae on them.
- Venomous: No
- Temperament: Semi-aggressive – More aggressive than other Zebrasoma.
- Compatible with:
- Same species – conspecifics: No
- Peaceful fish (gobies, dartfish, assessors, fairy wrasses): Monitor – Assessors may be too intimidated by their active swimming.
- Semi-Aggressive (anthias, clownfish, dwarf angels): Safe
- Monitor – Large damselfish may be too aggressive to a juvenile and subadult, especially if they eat the same foods.
- Large Semi-Aggressive (tangs, large angels, large wrasses): Safe – Do not house with other Zebrasoma.
- Large Aggressive, Predatory (lionfish, groupers, soapfish): Monitor – These fish, including frogfish and toadfish should be smaller than the tang or it will be eaten.
- Monitor – They will not bother mandarins and seahorses and pipefish should have their own tank.
- Anemones: Safe
- Mushroom Anemones – Corallimorphs: Safe
- LPS corals: Monitor – They have been known to nip at LPS.
- SPS corals: Safe
- Gorgonians, Sea Fans: Monitor – They may occasionally nip if not well fed.
- Leather Corals: Safe
- Soft Corals (xenias, tree corals): Safe
- Star Polyps, Organ Pipe Coral: Monitor – They may occasionally nip if not well fed.
- Zoanthids – Button Polyps, Sea Mats: Monitor – They may occasionally nip if not well fed.
- Sponges, Tunicates: Safe
- Shrimps, Crabs, Snails: Safe
- Starfish: Safe
- Feather Dusters, Bristle Worms, Flatworms: Monitor – They have been known to chew through the Feather Dusters tube.
- Clams, Scallops, Oysters: Monitor – They have been known to nip at clam mantles.
- Copepods, Amphipods, Mini Brittle Stars: Safe
Sex: Sexual differences
The male Zebrasoma is larger than the female and the males have white setae (hair-like bristles) in front of their peduncular spines. Females also have larger cloacas (reproductive/intestinal opening) than males
Breeding / Reproduction
The Purple Tang has not yet been bred in captivity. Some species of surgeonfish have spawned in public aquariums and there have been a few scattered reports of spawning in home aquariums, but regular spawning and the rearing of the young has not yet been reported.
For information on breeding and the development of the fry, see: Marine Fish Breeding: Tangs.
Tangs produce less body slime than other saltwater fish and have been termed “dry skinned” fish by some. This makes them very susceptible to Cryptocaryon (saltwater ich) and other diseases. The most common ailments are bacterial diseases, Lateral Line Disease, and parasitic infections such as protozoas (including Cryptocaryon), worms, etc.
For Crypt, 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.) or cleaner shrimp can help them by providing this cleaning service in the home aquarium. As for treatment, some tangs are sensitive to copper because they have an important microfauna in their digestive system, soprolonged or continuous use of a copper treatment is not advisable. It is also said that pellets soaked in garlic may help fend off Marine Ich
Providing a vitamin supplement (including vitamin C) can help provide for their nutritional needs, and vitamin C can help reduce Lateral Line Erosion (LLE) which may be caused by activated carbon. Enriching foods can be done by soaking dried pellets with liquid vitamins, adding vitamins to the food, or adding a liquid vitamin into the water. Some hobbyists also report success with supplemental foods such as previously boiled or frozen zucchini, broccoli, spinach, and leaf lettuce.
The best routine is a quarantine tank and a stress free environment with good quality veggie foods, places to hide and a quiet area for the aquarium.
For more information see Fish diseases.
The Purple Tang or Yellowtail Tang is only occasionally available. When they are available they are rather expensive, starting at about $100.00 USD for a tiny one, though they typically will run you $150.00 USD and up (Dec 2015).
-500 + ESSENTIAL-TO-KNOW AQUARIUM SPECIES
By Scott W. Michael
Copyright © 2001 by T.F.H. Publications, Inc.
-REEF AQUARIUM FISHES
500 + ESSENTIAL-TO-KNOW SPECIES
By Scott W. Michael
Copyright © 2005 by T.F.H. Publications, Inc.
-AQUARIST’S ONLINE MAGAZINE
AQUARIUM FISH: Surgeonfishes, A.K.A. the Tangs
By James W. Fatherree, M.Sc.
Copyright © 2002-2013 by Pomacanthus Publications, LLC, all rights reserved.
Fish Hole in the Head Disease
By Neale Monks, Ph.D.Copyright ©2013 I-5 Publishing, LLC. All rights reserved
-MARINE ECOLOGY PROGRESS SERIES
Growth and longevity in acanthurid fishes; an analysis of otolith increments
Department of Marine Biology, James Cook University, Townsvill, Queensland 4811 Australia
By J. H. Coat and L. M. Axe