Purple tang

Purple Tang Care: Zebrasoma xanthurum

The purple tang (Zebrasoma xanthurum) stands out as one of the most beautiful members of the surgeonfish group. The rich tones of their scales draw the eye immediately, even in a vibrant reef tank. However, they’re not tangs for the faint of heart – or the light of wallet. Purple tangs are some of the most expensive in the family. And they bring a few problems with them (as if that hit to your bank account wasn’t problematic enough).

Table of Contents: Purple Tang Care

When it comes to expense, a purple tang won’t run you anywhere near as much as its cousin the gem tang. But you still want to make sure you understand what you’re in for before making your purchase. Even if you’ve managed a surgeonfish or two before, you probably want to review the links below – just to make sure you have a handle on things.

Purple tangs are easy to recognize

Quick Facts

  • Common Names: Purple tang, Yellow-tail tang, Yellow-tail surgeonfish, Yellow-tail sailfin tang, Blue surgeonfish
  • Scientific Names: Zebrasoma xanthurum
  • Size: 8-10 inches (20.3-25.4cm)
  • Minimum Tank Size: 100 Gallons (379L)
  • Reef Safe? Yes
  • Care or Experience Level: Moderate
  • Preferred Diet: Omnivore
  • Original Part of the World: Indian Ocean, Red Sea, Persian Gulf

Description of the Purple Tang

As you probably guessed, the purple tang is a gorgeous shade of purple. You’ll see some variations along the blue to indigo range, but the rich saturation of that base color is what boosts them into popularity. The brilliant yellow highlights of the tail (and occasionally the pectoral fins) serve as the perfect accent. (To say nothing of leading to their other common name of yellow-tail tang)

Depending on the purple tang, you’ll also see rows and rows of tiny black dots. They form lines along the body, similar to the pattern you see in Kole tangs (Ctenochaetus strigosus). It isn’t always a guarantee, though. Some purples sport subtle dots that disappear in all of that deep color. You’ll only notice it close-up.

Similar to the sailfin tang, this surgeonfish has prominent dorsal and anal fins. When they extend all the way, the fish ends up as high as it is long. The purple tang won’t match the sailfin for size, but it exaggerates their discoid shape. And it gives aquarists one more thing to admire. (As if you needed something else, right?)

As with other surgeonfish, purple tangs possess a caudal spine on either side of their caudal peduncle. They use the “scalpel” for defense against predators and offense when defending their territory. It’s important to remember the spines exist when attempting to work around or handle these tangs. The scalpels can easily tangle in a net or lead to a hand injury. You want to remain aware of your purple tang at all times. (And use net alternatives if you need to transport them)

Purple Tang Lifespan

Initially, scientists believed purple tangs remained in the Red Sea. It wasn’t until recently they spotted that iconic indigo shade extending out to the Persian Gulf and even into the western portion of the Indian Ocean. The remote locations of their preferred reef territories are part of the reason they fetch such a high price on the market. (We’ll go into the second reason later on)

The variations in their bluish-indigo color and the dots along their sides make identifying individuals – even in a school – easy. This is why their lifespans are well documented, around 30-45 years, in the wild anyway. In captivity, hobbyists maintain their purple tangs for at least ten years (with optimal care).

Your purple tang will need some live rock in which to sleep

Creating the Ideal Purple World

If you’re an avid diver or snorkeler, you might spot a purple tang school on a reef in the Maldives, around Sri Lanka, or along the Ceylon coast. These remote vacation spots are favorites with the surgeonfish – and growing in tourism. It’s what led scientists to reevaluate the species range from the Red Sea, where they originally confined the tangs.

Purples comb reefs for algae throughout the daylight hours. Now and then, you might spot one close to the surface, but it’s a rare event. (Think of it as a curious dash to glimpse the sun) They’re more at home in deeper waters – up to 65 feet (20m). You’ll often spot them in large shoals, moving over the coral in search of a new spot to graze.

As with most members of the surgeonfish family, the best thing you can offer in your tank is SPACE. Purple tangs are active fish, and they need room to explore and swim. If you attempt to squeeze them into a crowded tank, you’ll increase their natural aggressive tendencies. (And everyone knows about the famous tang mean streak) The more open swimming room you can offer, the better.

But you don’t want a barren tank. Purples squeeze themselves into crevices in live rock when they retire for the night. So you’ll want to add a few structures around the perimeter. It’ll also provide them with places to graze. Finding a proper balance between that open tank space and “sleeping quarters” is an essential part of their care. If you notice your purple tang’s color fading, it’s possible they’re feeling stressed. You DON’T want to see that!

Purple Tang Tank Size

Purple tangs replicate a sailfin shape, but they don’t get as large as their impressive cousins. You’ll usually only see them reach around 9 inches (22.9cm) in captivity. It’s enough to command a healthy presence in your reef tank, though. So you shouldn’t go any smaller than 100 gallons (379L).

Realistically, if you have the room, you want to go larger. This will offer your tang the swimming space they crave. (To say nothing of some pockets for that live rock) It’ll also help to diffuse any potential aggression directed toward their tank mates. When purple tangs feel confined, they take it out on their neighbors.

And since purple tangs are prone to head and lateral line erosion (HLLE), more tank volume may help. In theory, it should take more volume of pollution and/or a longer time to become problematic. When water conditions start to go down, you can see those tell-tale wounds appear on the tang’s head and body. It’s a red flag that you need to attend to your filters or protein skimmers. If you choose a larger tank, ammonia and nitrates dissolve over a greater surface area.

Purple tangs also appreciate a strong current. You’ll want to invest in a quality power head to up the water flow in your tank. It’ll offer a chance for them to exercise their fins AND increase the oxygen content in your aquarium. Both are pluses when it comes to this species.

Are Purple Tangs Reef-Safe?

With a penchant for algae, purple tangs are an ideal species for reef tanks. They hunt down pesky hair algae between corals without disturbing the delicate polyps. And their foraging habits won’t cause a problem for any of your other invertebrates. They’re the perfect fish (you know, minus their other quirks).

Purple tangs spend the majority of their day grazing on algae

Purple Tang Diet

In the wild, purple tangs gravitate toward the herbivore side of their omnivore habit. You’ll find them scouring reefs for filamentous algae. And they’ll happily oblige you by rooting out any algae that pops up in your reef tank. But the odds of enough hair algae (or any other species) growing to satisfy their high metabolism isn’t great.

For that reason, you’ll need to augment their diet with plenty of other sources of greens. You can do this with veggie clips of nori tucked around the aquarium. Or you can grow macroalgae in a refugium to have a ready supply. Either works, provided you offer enough for daily grazing habits.

You should also plan to add protein sources. A healthy purple tang retains a slightly plump shape. (It’s not as easy as it sounds, as they move CONSTANTLY, burning up fat reserves) They aren’t terribly picky, so you have your choice of supplemental food types:

Keep their activity level in mind. A single feeding a day won’t do the trick. You’ll want to offer food 2-3 times during the daylight hours. That way, you have a better chance of meeting those high calorie needs.

Purple Tang Behavior and Tank Mates

Purple tangs don’t seem to mind sharing reef space with one another – in their natural range. You’ll often spot them in pairs or large schools. Only youngsters hang out in isolation. As they get older, they gravitate into groups as they patrol the coral in search of their next meal.

All of that activity leaves little time for the niceties in life. And purple tangs are prone to infestations with marine ich and other parasites. So these surgeonfish make use of cleaning stations. It’s common to see these tangs waiting patiently while a cleaner wrasse or cleaner shrimp works to pull those unwanted pests from their scales.

Unfortunately, it’s a different story when you shift to a home aquarium. Within the confines of even a large tank, that famous surgeonfish aggression comes out. Purple tangs no longer tolerate sharing a territory with each other. You’ll see fighting with those caudal spines. And these vibrant tangs will even go after tangs with a similar shape. (Yellow tangs are common targets)

Some hobbyists attempt to deflect the aggressive streak by introducing multiple purples at the same time. It prevents any one fish from establishing a territory before the others. But it’s not a guarantee against future problems. You’re better off sticking to ONE purple tang. And then avoid any other surgeonfish with a similar shape. (Better yet, avoid the Zebrasoma genus entirely)

Luckily, that still leaves plenty of colorful fish to create a dynamic reef tank. As long as you avoid timid fish (all of that constant activity tends to be too much), you’re usually in the clear with most species:

  • Angelfish
  • Clownfish
  • Gobies
  • Rabbitfish
  • Wrasses

Your purple tang will benefit from a cleaner wrasse tank mate

Breeding Purple Tangs

You’ll need a male and female purple tang to tell them apart. The differences are subtle. It comes down to size: males are SLIGHTLY larger. And if you manage to catch the pair during spawning season, males put on a brighter coloration to attract a mate. Otherwise, both sexes look identical.

Of course, if you’re hoping to breed this species, you might want to focus your finances elsewhere. (Say, on the purchase price of ONE fish) They’re notoriously difficult to breed in captive settings. Bali Aquarich was the first commercial company to succeed – in 2019. And even they didn’t set up commercial production until 2020. It’s positive (removing the need to take fish off the reef), but the selectivity – and rarity – contributes to the high purchase price of purple tangs.

As with other tang species, purple tangs are broadcast spawners. And keeping even two together? That usually requires a tank size reserved for public aquariums. (Incidentally, a few of those have successfully bred the species) But at least you know captive purple tangs DO exist!

Pros and Cons

Any time you’re facing the possibility of spending over $100 on a fish, you want to consider the decision carefully. (No spur-of-the-moment decisions here) Sure, purple tangs are striking in color. But what about some of the other pros and cons?

Pros

  • Purple tangs are now available captive-bred, with better social manners and higher adaptability to home aquarium conditions.
  • Leaning toward the herbivore side of the menu, purples will happily rid your tank of any hair or other filamentous algae.
  • Purple tangs enjoy bright lighting – the perfect setting to show off their vibrant scales and support your favorite corals.

Cons

  • Due to the remote locations of their range and the limited availability of commercial breeding, purple tangs come in on the pricey side.
  • Purple tangs are known for developing head and lateral line erosion. You need to watch for open wounds and stay on top of their water quality and diet.
  • Quarantine is a strict requirement for any wild-caught purple tangs as they often bring ich and other diseases with them.

For More Information

Once you’ve decided you need a purple tang in your aquarium, nothing will dissuade you. (Nope, not even that price tag) But if you’re still on the fence about opening your piggy bank, maybe a few more nuggets of information will sway you.

Let’s start with this YouTube video spotlighting the purple tang:

Want to know about some of the best purple tang tank mates?

Or how about potential cleaners to keep your purple tang looking its best?

Conclusions

You can pick out purple tangs in an instant. The rich hues of their scales beg to adorn a reef tank. And their helpful habit of rooting out algae offers to compensate you for that hefty price tag.

You just need to provide enough room to tone down their aggressive tendencies. And, you know, avoid any tang interactions. Oh, and watch that water quality. Probably shouldn’t allow any slip-ups in diet, either.

Once you get all of that sorted, though, you’re definitely in the clear! And if you’re willing to put in the time and effort, your purple tang will reward you with its beauty.

Purple tang large image for pinterest

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References

  • Fatherree, J.W. 2009. “Aquarium Fish: Surgeonfishes, A.K.A. The Tangs.”
  • Fenner, B. “The Sailfin Tangs, Surgeons, Doctorfishes of the Genus Zebrasoma.” Wet Web Media.
  • Fenner, B. 2013. “Surgeons, Tangs, and Doctorfishes, Family Acanthuridae.” Wet Web Media.
  • Michael, S.W. 2001. Marine Fishes: 500+ Essential to Know Aquarium Species.

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