Blue hippo tang

Blue Hippo Tang Care Guide: Paracanthus hepatus

There are actually three different, popular saltwater fish species that share the common name, blue tang. The Powder blue tang, the Atlantic blue tang are beautiful fish, but the most famous and popular of the three is the Royal blue tang, Paracanthus hepatus, made popular by the Pixar movies Finding Nemo and Finding Dory. 

Truth be told, this fish was amazing before the movies and is one of the most beautiful species you’ll encounter. But let’s explore what it takes to care for these delicate fish in your own reef tank. So grab P. Sherman, and let’s start swimming.

Table of Contents: Blue Hippo Tang

Who doesn’t love colorful aquarium fish? And the various types of tangs offer some of the best options out there. If you’ve ever wanted one of these gorgeous members of the surgeonfish family, we’ll dive into the best way to care for the blue hippo tang in a reef tank. The links below will help you navigate through the ins and outs of this challenging species. (No need for fluency in whale)

Blue Hippo Tang

Quick Facts

  • Scientific Name: Paracanthurus hepatus
  • Common Names: Blue hippo tang, Regal tang, Pacific blue tang, Hepatus tang, Flagtail, Palette surgeonfish
  • Size of Fish: 12-inches (30.5cm) as an adult
  • Minimum Tank Size: 100 gallons (380L) ++ (some say 180 gallon/680L!)
  • Reef-Safe? Yes
  • Care Level: Moderate
  • Diet: Herbivorous; Needs algae in the diet to stay healthy
  • Aggression: Semi-aggressive
  • Aquacultured: Has been raised from eggs, but not broadly commercially available

What is the ideal tank size for a Blue tang?

The Blue Tang, Paracanthurus hepatus, should be kept in a tank volume of at least 100 gallons (378.5 liters). A tank of this size is likely 6-feet long, which provides the 12-inch long adult fish enough room to swim naturally and forage on the aquarium rocks and glass for algae films.

Other Names for the Blue Hippo Tang

Shakespeare gets the credit for the saying, “A rose by any other name would smell just as sweet.” I’m not sure blue hippo tangs smell any differently depending on where you find them, but they DO go by different names. You’ll find them listed as regal tangs, palette surgeonfish, Pacific blue tangs, hepatus tangs, flagtail surgeonfish, Pacific regal blue tangs (that’s one of the longest in the bunch), and even more possibilities. The Latin name Paracanthurus hepatus is the only one a taxonomist would pick out of the mix, though.

And as if that jumble weren’t enough, there’s a wrinkle in the mix. You can find ANOTHER blue tang out there. Acanthurus coeruleus goes by blue tang on occasion. It isn’t (quite) related, though – other than being part of the tang group. And the two don’t look the same. Just goes to show you Shakespeare got it right: there’s MUCH more to a name.

School of blue hippo tangs

Blue Tang Care Guide

When it comes to caring for blue hippo tangs, it’s essential to do your research FIRST. These vibrant members of the surgeonfish family aren’t for everyone. And while popular, they often prove too much to handle for novice aquarists.

They pop up in fish stores as tiny, 1-inch (2.5cm) juvenile fish. To an unsuspecting saltwater fish tank owner whose children recently watched Finding Nemo or Finding Dory, the tang looks like a fish nugget and seems manageable enough. They make the purchase and plop the blue and yellow tang into a starter tank, not realizing the potential problem down the road. Blue hippo tangs can grow up to 12-inches (30.5cm) in length as adults. They need room for that eventual size. Plus space to swim. That translates into a tank of At LEAST 100 gallons (380L), though some hobbyists argue you shouldn’t go smaller than 180 gallons (680L).

As if a large adult size weren’t enough, blue hippo tangs – unlike most captive tangs – are shoaling, active swimmers. In the wild, you see them zipping around the reef, nipping algae from the rocks. They form schools they’re happy to maintain when they enter a home aquarium. (Disney and Pixar got that right) While most surgeonfish grow too aggressive to share space in a confined environment, blue hippo tangs enjoy each other’s company. And that means providing room for EVERYONE. It’s tough to recreate that amount of space in the home aquarium.

Add all of those needs together, and you’re looking at a staggering tank size. This is why many passionate tang lovers advocate for tanks over 180 gallons (680L). And that makes caring for this amazing species unapproachable for the average saltwater fish tank owner. If you’re an experienced aquarist, you could attempt to care for them in a smaller aquarium. But many people have strong opinions that you’re going too small for the health and safety of your tangs.

Provided with appropriate space to swim and explore, blue hippo tangs exhibit model behavior. Again, they’re social butterflies (in the surgeonfish world). And as long as you don’t have other tangs in your tank, you’ll find your tang mild-mannered. However, they CAN turn skittish. Some blue hippos even up afraid of their own shadows. That’s where appropriate decor comes in. But before we can address that, we need to get your blue hippo tang safely INTO the aquarium. And that’s a challenge in and of itself.

Quarantine: essential step to blue tang care

As with any member of the surgeonfish family, blue hippo tangs possess a caudal spine. It lies on either side of the caudal peduncle (hence, why it’s called a caudal spine). The spine works for defense AND offense in the wild. It protects the fish from predators, and they use it to battle one another for territory. But it can also cause problems when you’re working with your new arrivals. If you attempt to use a net with tangs, that spine can end up tangled within the weave. It’s better to use a plastic container.

Blue hippos should ALWAYS spend a minimum of two weeks in quarantine. While considered relatively disease-resistant when they’re acclimated and introduced to your display tank, they DO tend to bring a few common diseases with them. You don’t want an outbreak of marine ich in your tank. Now, I recommend you quarantine everything before you add it to your tank. That’s simply practical. But the practice goes double when you have any species of tang. We’ll go over their diseases in a minute. For now, pop your lovely blue and yellow tang in quarantine.

Once you’re sure the fish looks clear of (evident) disease. You can use that plastic container for transfer. It’s less stressful than a net. And you’re less likely to cause any damage – to you, the net, or your blue hippo.

Blue hippo tangs need at least two weeks in quarantine

Hiding: how your Blue tang may behave

Blue hippo tangs look bold with that cobalt and yellow color pattern. (And, let’s face it, Dory set some precedence with her out-going personality) But they actually rank at the top of the shy spectrum for tangs. You tend to see them retiring to the background a bit. And they’re not big on confrontation. Quite the opposite, actually. If something startles them, the first impulse is to head for the hills. Rather, it’s to head to the coral.

A frightened tang will hide behind or wedge itself into rockwork. As such, you need to provide live rock with crevices and caves that offer a handy retreat. But you also want to make sure your coral frags are firmly glued on. This will prevent any injuries or accidents as they bolt for cover. (Blue hippos don’t announce they’re about to topple a frag) And having somewhere “safe” will decrease the stress the fish experiences. Lower stress levels equate to higher health.

When acclimating your new fish to your tank, consider dampening your lights and avoiding rapid, imposing motions in front of the tank. This will help you avoid sending your new blue hippo fleeing deep into the aquascape. You’ll also want to keep SOME kind of hiding space available. After all, while the tang’s in quarantine, YOU’RE the biggest threat they’re likely to encounter.

Playing dead: how a Regal Blue tang may react to stress in an aquarium

Yes, it sounds crazy (or like it belongs to one of the Pixar movies). But blue tangs engage in a predator-avoidance behavior that involves playing dead. They go limp, resulting in a horizontal posture. The fish stays completely still until the predator moves on. And in a mixed aquarium – particularly when the blue hippo can’t reach a hiding place – you might see the behavior. This, of course, can produce panic as you wonder if your blue hippo tang (which you took such pains to care for) is ACTUALLY dead. Watch for continued movement.

I’ve yet to see a blue hippo tang play dead. But I’ve decided I MUST see it before I die. (I just added it to my bucket list)

Al's Bucket List

Are Blue tangs Reef-Safe?

Blue tangs are reef safe saltwater fish. They will generally live peacefully with corals, shrimp, clams, crabs and other reef invertebrates.

Dory and Marlin traveled all over the Pacific, experiencing plenty of different environments. But you see them calling a reef Home Sweet Home. And you’re probably anticipating setting up your new surgeonfish addition in a reef tank. (Those colors look smashing against such a backdrop) Now you just need to make sure you’re not inviting disaster. Luckily for you, the blue hippo tang is a reef-safe saltwater aquarium fish.

With their herbivorous diet, the tangs actually PROMOTE the health and well-being of your corals. They feed on algae, trimming away any of the pesky growth that might attempt to compete with your corals. And they do so without harming a single polyp in the process. They’ll also leave your clams, shrimp, and crabs alone. So you can add them into almost any tank environment without a problem. (We’ll go into the exceptions in a second)

Blue Tang Compatibility

The blue hippo tang is generally peaceful toward other saltwater fish. However, they are territorial like any member of the tang group. So your best bet is to keep them as a single tang specimen or school. By nature, blue hippos ARE shoaling fish. So it’s possible to have a school in a tank – with a few hundred gallons (thousand liters) of swimming volume. For this humble hobbyist, I’ll try to send my children to college before I take on that expense (I suspect it comes out pretty close to a wash there).

Your best bet for a school is introducing all of the fish at the same time. It prevents squabbles over territory. (Since everyone enters the pool at the same time, no one gets to hog the diving board) Of course, you’re not going to get around the space issue. If you don’t supply enough room for your tangs, there’s a good chance they will fight until one of them is dead. I’ve seen it happen in a local fish store between two yellow tangs (also fantastic fish).

Two yellow tangs fighting in a tank

Otherwise, you can pair up blue hippo tangs with almost any other non-tang species you can think of. That shy streak makes them peaceful tank mates. Tiny fish like gobies go right under their radar. And big guys that won’t hassle them (such as groupers) work well, too.

You don’t want to go with anything aggressive, though, or they’ll end up getting picked on. (Yeah, fish get teased for having freckles, too) So watch out for the bigger angelfish out there, dottybacks, and triggerfish.

And, of course, if you want to replicate your favorite Pixar flick, blue hippos don’t have a problem sharing an aquarium with clownfish.

What are the best Blue Tang Tank mates?

The Blue Tang can be safely kept with many of the most popular community saltwater fish, including most clownfish, gobies, blennies, cardinalfish, and dwarf angelfish. Advanced aquarium owners have also successfully kept Paracanthurus hepatus with other Tang and Surgeonfish species as tank mates, by acclimating the tangs to very large aquarium systems at the same time.

Feeding Blue Tangs

Blue hippo tangs are herbivores. That means they need plant and animal matter in their diet. (No, you didn’t read that wrong) Every fish, regardless of diet, needs a little protein to remain healthy. And these tangs usually get their protein source from the plankton. Then they bulk the remainder of their diet out with macroalgae they graze from the rocks and algae. And if you’re going to keep your blue hippo round and full, you need to make sure you have enough space to provide all of that food.

(Hint, this is why it’s recommended that you have a tank of at least 180 gallons/680L)

Blue hippo tang and live rock


Algae grow on available surfaces within a saltwater aquarium. So it’s best if you have plenty of live rock for your tang to graze on. Odds are you won’t see enough algae to supply the dietary needs of even ONE blue hippo tang, though. So having a refugium handy to grow out additional supplies is a good idea. You should also add in regular feedings of nori or other seaweed for best health. A veggie clip added around the tank will do the trick. In addition to nori, I feed my tangs spirulina flakes.

Nagai Deluxe Sushi Nori

You also need to keep that meaty protein side in mind. If you don’t, you’ll start noticing health problems in your tang. Vitamin deficiencies lead to common issues, such as hole in the head disease. (We’ll go into this more in a moment) To avoid this, you want to add a little meaty treat to your tank now and then. Enriched brine or mysis shrimp work nicely (and blue hippo tangs enjoy them). If you gut-load with green water algae, you’ll boost the nutrition of the tiny crustaceans before your tangs eat them.

Diseases and Infections common to Blue Tangs

Unfortunately, while blue hippo tangs are wildly popular, they’re also prone to trouble with infections and disease in a reef tank. If you’re not staying on top of their dietary needs, the water quality in your aquarium, and the stress levels of your fish, you could find yourself with problems. A proper quarantine, high-quality products in the diet, and attention to the well-being of your tang will go a long way to preventing these problems from showing up.

Diseases and starvation in blue hippo tangs
Saltwater ich (top left), Head and Lateral Line Erosion-HLLE (top right), and Starvation (bottom)

Tangs, in general, are prone to protozoan diseases such as velvet and marine ich. (This is why that two-week quarantine is so critical) Immunity, stress, and exposure to the parasites influence whether or not they succumb to these protozoan infections. Diet is also thought to be a factor affecting their immune system. So many aquarists (and sites like LiveAquaria) recommend adequate feedings of seaweed diets. A happy, well-fed blue hippo tang is more likely to fight off the protozoan. A stressed, starving tang? Not so much.

I’ve also seen some pretty terrible Head and Lateral Line Erosion (HLLE) cases in these fish. This is generally thought to be an environmental disease. This means the conditions of the water/aquarium (and a compromised immune system) cause the issue. Improper dietary health (again) also contributes. HLLE has also been associated with activated carbon use. “Fines” (small charcoal dust) can irritate their skin and lateral lines. If you see wounds on the head or side of your blue hippo, you need to investigate your tank for problems.

Blue hippo tang demonstrating extreme ill health

You do NOT want to see your blue hippo tang reach the state of the image above. This poor sick fella was at a business in New Jersey. (Yes, that really is a blue hippo. When they reach a point of extreme illness, they turn white) Please don’t let this happen to your tang – or any fish, for that matter. If you start to see anything like this in your fish, please ask someone for help.

For More Information

Blue hippo tangs enchanted people well before Finding Nemo hit the big screen. The movie (and its sequel) just fanned the flames of their popularity. Unhappily, the rush to bring one of these gems home generated a lot of sick and uncomfortable fish as people failed to understand their care needs.

If you have an extra few minutes, check out this YouTube video for more information about how to care for a blue hippo tang:

Finding Dory: How to Care for a Blue Tang ("Dory") in a Saltwater Aquarium

If you are trying to pick the perfect tang for your tank, I recommend you check out a few of these other great and popular surgeonfish:

Or perhaps you’re looking for another fish with brilliant blue and yellow colors? You might want to check out the Yellowtail damselfish.

Looking for something completely different? How about the Lawnmower blenny?

New to the hobby? Check out: How to set up a saltwater aquarium.

Finding Nemo fish (the real species)

There’s a good chance that if you’re looking into the blue tang, you probably are a fan of Finding Nemo and Finding Dory. If you’re looking to learn more about Nemo and Dory’s friends, you may want to check out:


The blue hippo tang is a fantastic fish. It’s practically a movie star, courtesy of Dory (and, you know, Disney and Pixar). And as long as you do your homework and some preparation, it isn’t that hard to care for. They require algae-based diets and clean water, but so do plenty of other popular reef fish. The biggest challenge is their size and the need for lots of room to swim. Do you have a tank big enough to keep this beauty? And are you prepared for every kid in the neighborhood to come over to say “hi” to Dory?

Hopefully, we will see advances in the captive rearing of this amazing fish, which will usher in an entirely new level of hardiness and availability.

Please pin and share the image below on Pinterest.

Blue hippo tang care guide



DiMaggio, M.A., Cassiano, E.J., Barden, K.P., Ramee, S.W., Ohs, C.L. and Watson, C.A. (2017), First Record of Captive Larval Culture and Metamorphosis of the Pacific Blue Tang, Paracanthurus hepatus. J World Aquacult Soc, 48: 393-401.





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