Sohal Tang Care Guide: Acanthurus sohal

The easiest way to identify a Sohal tang is by its vermiculated stripes. In other words, the wavy lines that streak down their body. (Given the option, though, doesn’t vermiculated sound cooler?) The stripes alternate between dark and light. And where the fins meet the body, you’ll find electric blue margins.

The fins themselves usually come in some shade of yellow – save for the region around the caudal peduncle. Where the sohal tang hides its “scalpel,” you’ll see an orange highlight. Yes, it’s meant to call attention to that defensive/offensive mechanism. A similar orange patch enhances the gills (not as a warning, though; it’s decorative there).

This is a unique color palette for a tang, and it stands out on the reef. So does the impressive size of this species. In the wild, it’s common to see sohal tangs up to 16 inches (40.6cm) long! That’s a lot of fish to carry around the trademark tang attitude. It also means you’ll need to take care when handling your sohal. That caudal spine can leave some nasty wounds on your hands if you’re not careful. You’ll want to skip using a net and opt for a container with solid sides.

They can also inflict significant wounds on tank mates. If they feel “spicy” or threatened in any way, they use the spine to defend themselves. Punctures or lacerations from the spine can leave openings for infection. So choosing the tank mates for these vermiculated bruisers (which we’ll get to) can get tricky.

Sohal tangs prefer a narrower regional range to some of their cousins. They stay around the Red and Persian Seas, with a few populations flirting into the western Indian Ocean. This is why you may see them listed under the common names Arabian tang or Red Sea clown surgeon (the clown part’s due to the various colors). They stay around the reefs in those areas.

The patterns of those vermiculated stripes (see? It’s fun to say!) make identifying individual fish easy. And tracking their growth by researchers isn’t tricky. Sohal tangs can live for up to 15 years. You can expect a similar lifespan in captivity -with the proper management, of course.

Sohal tangs are popular sights throughout the Red Sea. They haunt shallow coral reefs and the lagoon flats throughout the area. This works well for wild-collection purposes. (Don’t worry, we’ll get into why that’s an important fact in a minute) Almost all Red Sea fish species get collected by a net. It makes for gentler handling and less stress in the fish’s transport. And when you’re dealing with a fish the size of the sohal? You want as much relaxation as possible.

Of course, no fish is immune from predators. (Nope, not even sharks) Sohal tangs need somewhere to hide and feel safe. Their preferred option is stretches of Acropora colonies. The branches provide the perfect refuge. Most of the toothy predators in the region will pause and think twice before chasing a tang among the twisting skeletons. (Not to mention they’d struggle to fit)

The need for live rock doesn’t stop there, though. You need other nooks and crannies when you start building your structures. The twist is, you’re not attempting to hide your tang. Nope. The rockwork you create within your saltwater aquarium is meant to shelter the sohal’s tank mates. Remember the famous aggression surgeonfish are known for? Well, in home aquariums, sohal tangs usually reign supreme. And they’ll bully anyone and everyone they come across. So you need to offer a refuge for the other fish in the tank.

But that needs to balance with open swimming room. Sohals move FAST. And they’re naturally active fish. You need to keep enough space in the aquarium to accommodate the movement of the tang. If they feel cramped or crowded by the aquascaping, you’re going to boost their crankiness. (And it’s already near the top of the scale) This is one of the things that makes keeping this species particularly tricky.

Sohal Tang Tank Size

Sohal tangs can grow up to 16 inches (40.6cm) as adults. While they usually end up smaller in home aquariums, you’re still looking at a brute of a fish – emphasis on the “brute.” Sohals have a nasty streak. Combine the two, and you’re looking at a significant tank size.

At a minimum, you shouldn’t go smaller than 250 gallons (946L). And, if you have the space, you want a length of at least 8 feet (2.5m). That will provide the swimming room your sohal tang craves. It’s a tall order for most hobbyists. (Hopefully, you understand those dimensions are for ONE tang)

Are Sohal Tangs Reef-Safe?

As Sohal tangs frequently use Acropora coral beds to escape predators, you’d imagine they’re a reef-safe species. For the most part, you’d be right. They fall on the herbivore side, with no interest in chewing on coral polyps. As they forage for algae throughout your tank, they should leave your prize corals alone.

Emphasis on SHOULD.

The problem comes in when you don’t keep up with the amount of food this energetic tang species needs. Hungry sohal tangs start eyeing large polyp stony (LPS) corals. And hobbyists have noted their fish chewing on the branches. It isn’t a behavioral issue, though; it’s a cry for help. If you see your sohal nibbling the polyps, it means they’re HUNGRY. You need to examine your feeding regime – and fast.

Sohal Tang Diet

Most clean, cycled, healthy tanks won’t produce enough algae to sustain an adult sohal tang. So you’ll need to supplement their foraging. You can do this with a refugium stocked with macroalgae. Or you can offer a veggie clip with nori. You CAN go the route of commercial flakes and pellets that contain marine-based seaweed, but you’ll need to soak them in a vitamin supplement to prevent unwanted deficiencies.

Don’t slide to an all-veggie diet, either. Sohal tangs need some protein in their lives, too. (That’s where those bright vermiculated stripes come from) You can offer a few easy fishy favorites to fill that gap in the diet:

Finally, let’s discuss the all-important feeding routine. Sohal tangs are ACTIVE fish. You created that swimming space for them in your tank, and they’re going to use it. To fuel their metabolism, you need to offer food at least three times a day. If you fail to keep your sohal’s stomach comfortably full, they’ll start eyeing other options in the tank. That’s when you can start losing your corals (or ornamental shrimp).

Sohal Tang Behavior and Tank Mates

Would you believe there’s a tang species out there aggressive enough to take on parrotfish and triggerfish? Sohal tangs have a mean streak that goes straight to the bone. In the wild, divers have spotted these vermiculated beauties chasing off other bruisers in the fish world from their territory. They simply don’t play well with others.

That “bully” attitude can make them challenging to incorporate into a community aquarium. Now, you obviously don’t want to attempt to house them with ANY other tangs. (Let’s not do anything crazy) And even trying to go for larger tank mates can backfire on a hobbyist. Sohals display little fear in captivity, challenging species twice their size for supremacy. And if another fish looks similar? (They want to remain vermiculated champ) Yeah, you’re in for the aggression battle of the world.

Your best bet for some semblance of peace is to add your sohal tang LAST. Without an established territory to defend, the fish tends to remain on its best behavior. (You know, as good as that behavior gets) Adding new tank mates after a sohal is a recipe for disaster. They’ll bully the newcomer, sometimes to death.

Providing enough room – and hiding places – is another crucial component to managing this bruiser of a tang. They aren’t afraid to throw that size around. So provide your fish with as much open space as possible to get out of the way.

Most hobbyists concede defeat and house a sohal tang alone in a gorgeous reef tank. It provides them with peace of mind. And there’s nothing wrong with choosing that option. The fish won’t mind the lack of company (after all, it’s not like sohal tangs LOOK to cause trouble). You’ll still get a gorgeous display. And you won’t need to walk into the room one day and find the results of a horrible battle.

If you want to attempt a community, go for aggression. (Sounds insane, right?) You need species that can hold their own against the sohal tang’s fierce temperament. Just avoid similar vermiculated patterns. And NO tangs – no matter how fearsome:

• Large angelfish
• Triggerfish
• Tuskfish

As you’ve probably guessed by now, breeding sohal tangs in captivity hasn’t yielded much success. Keeping two in the same tank doesn’t end well. Hobbyists rely on wild-caught specimens for their tanks. Of course, that means a high cost.

In the wild, Sohal tangs get along a little better. (The Red Sea provides more space than the average aquarium) There’s no external difference between the male and female. (That’s something else that can complicate captive-breeding) Pairs come together and scatter their gametes into the current. The eggs drift with the plankton. After a few metamorphoses, tiny Sohal tangs drift down to the reef.

Replicating that set-up in captivity gets complicated. You’d need a MASSIVE tank – something along the lines of a commercial operation. So, for now, wild collection will remain the mainstay of things.

Pros and Cons

Imagine the number of times you’ll get to say “vermiculated” when you pick up a sohal tang and add it to your saltwater aquarium. (Not to mention the number of times you get to explain what it means) The species is gorgeous, active, and helpful. That’s three checkboxes right there. But you’ll also have to contend with some downsides. Finding the balance point is important if you’re going to spring for the expense.

Pros

• Sohal tangs undergo wild collection in nets, resulting in lower stress and a higher survival rate.
• These tangs are energetic and fast-swimming, creating a dynamic reef tank.
• Sohal tangs happily feed on hair algae, eradicating the pest from your aquarium.

Cons

• Sohal tangs require an algae-heavy diet. Without it, they can develop lateral line erosion.
• Due to the size of the adult tang, you need to provide a large tank – at least 250 gallons/946L and 8 feet/2.5m in length – with plenty of open swimming room.
• Sohal tangs are notoriously aggressive, even challenging species twice their size for dominance within an aquarium. You may need to resign yourself to keeping them alone in a tank.

Sohal tangs look stunning. And – once you get past that brutish reputation – they make for an engaging and dynamic reef tank display. Sure, they’re a bit on the mean side. But what tang isn’t? If you’re willing to put in the effort and work to set up an aquarium that will keep them happy – and their tank mates safe – you couldn’t ask for better. So let’s dive into a few more nuggets of information on sohal tangs, shall we?

This YouTube video walks you through everything you need to know about sohal tangs:

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

Maybe the sohal tang is too much for you to handle. Let’s look at a few (kinder, gentler) surgeonfish alternatives:

Sohal tangs aren’t the only “loners” out there. These species do best on their own, too:

Conclusions

Seeing the colors and vermiculated stripes of a sohal tang immediately calls to mind a lush, tropical paradise. And they’re the perfect addition to a thriving reef tank. They just don’t do as well in the average community. You need to choose aggressive tank mates. Or, you know, skip fishy tank mates.

Once you understand the needs of the sohal’s temperament, though, their care isn’t terribly complicated. And you’ll find yourself wondering how you ever kept a tank without them.

Or made it through a day without saying “vermiculated.”

References