Diet, Tank Size, Mates and Breeding


Clown Tangs are not an easy fish to keep in your saltwater aquarium so make sure you learn as much as you can to reduce the learning curve. These fish are good looking with their alternating yellow and blue stripes and purple/bluish bottoms and their diet is not too complicated since they like plant-based foods like the algae growing among your tank’s live rock.

The Clowns get aggressive as they grow so choosing the right tank mates is critical for a peaceful aquarium. We hope this guide provides you with a new set of skills and helps you succeed with your Clown Tang.

Species Summary

Clown Tangs are striking members of the Surgeonfish family. Their scientific name, Acanthurus lineatus, comes from the Greek words akantha, meaning thorn, and oura, meaning tail. These fish have a unique forked tail that dazzlingly cuts through the water as they swim.

The species is native to the Indo-Pacific region, spanning the waters between East Africa and Hawaii. They reach north to Japan and south to the Great Barrier Reef. Clown Tangs, also known as Striped Tangs and Lined Surgeonfish, reach a depth of 50 feet but spend most of their time between 3 and 10 feet below the surface. This depth and their vibrant coloration make them easy to spot for divers.

Clowns are always wild-caught and thus adapted to feeding across sprawling reef systems. As a result, they can be needy fish, making them most suitable for experienced aquarists with well-developed tanks. They reward your care with an active lifestyle and visual pop to any setup.


These fish have the broad, flat-shaped bodies characteristic of all surgeonfish. Clowns’ defining and namesake characteristic is their coloration. The top three-quarters of their bodies, from head to tail, are covered in alternating yellow and blue with black-edged stripes that usually run horizontally. The bottom quarter of the fish is a pale purple or bluish-white shade.

Clowns have short snouts with small mouths filled with spatulated teeth featuring denticulate edges. The stripes on their face typically run diagonally. They have a long, continuous dorsal fin that spans from the top of their heads to the caudal.

The tailfin is forked, with a broad separation between the tines. The fin features black or darker-toned piping. The flesh of the tail features blue and yellow coloring with an asymmetrical pattern.

Author Note: Like their fellow Tangs, Clowns have two peduncle spikes extending from either side of their anal fin, which serve as a defense mechanism and weapon in territorial fights.

Clown Tang swimming in a saltwater aquarium


Wild Clown Tangs have a lifespan between 25 and 30 years while captive fish usually only make it to 10. Tank life emphasizes these fish’s prickly nature and susceptibility to stress. These factors, combined with their large size, shorten their lifespans.

Average Size

Clown Tangs can reach an average size of 12 to 14 inches long, making them one of the largest members of the Surgeonfish family.

Clown Tang Care

Clown Tangs are strong, active swimmers who gravitate toward wild reefs with strong currents. This swimming ability complicates housing them in a home tank because all fish do best with conditions that effectively simulate their natural environment.

Tank Size

Your Clown Tang needs a minimum tank size of 250 gallons to accommodate its swimming needs. When considering layouts, opt for longer, rectangular aquariums. These fish roam rather than dive, so more swimming space is preferable to a tall tank. Experts recommend a 6-foot or longer tank.

Water Parameters

  • Water temperature: 75 to 82°F
  • pH levels: 8.1 to 8.4
  • Water hardness: 8 to 12 dKH
  • Specific gravity: 1.020 to 1.025

Tank Setup

Clown Tangs are herbivorous foragers that require tanks with plenty of live rock to scour for algae. However, do not overcrowd the tank because they still need open water to accommodate their need to swim and explore. Space the rock wide enough to allow the Tang to hide when uncomfortable or shy.

Author Note: These fish are powerful and can easily leap from your tank. Make sure your setup has a securely attached lid.


These fish do fine with standard aquarium lighting and a consistent day-night schedule.


Clowns are sensitive to water changes and the build-up of toxic contaminants. Due to the size of the tank, it’s best to rely on strong mechanical filters to maintain appropriate water quality. The tank also needs an appropriately sized powerhead to establish the current these fish need to thrive. Beyond creating optimal swimming conditions, an adequate current oxygenates the water.

In addition, investing in an Auto Top Off (ATO) device, which replaces evaporated water, and a protein skimmer will maximize the water conditions to prevent the changes in water parameters that could compromise your fish’s health.


Like other Tangs, Clowns lack quality immune systems and can easily carry disease into your tank. They are also stress-prone and tolerate the shipping and delivery processes poorly.

Author Note: Experts recommend using the slow drip method for one hour to acclimate Clowns to the destination tank conditions. 

It’s best to isolate them in a quarantine tank for at least two weeks while monitoring for signs of disease before introducing them to the home tank.

Are Clown Tangs Reef-Safe?

Yes. Despite being active foragers, Clown Tangs are reef safe and will not disturb your coral polyps. Unlike other Tangs, they won’t nibble on the reef components when stressed or agitated. Clowns also crave filamentous algae. Their dietary habitats will help keep your reef vibrant and clean.

Common Possible Diseases & Prevention

Like many other surgeonfish, Clowns are prone to Marine Ich and Head and Lateral Line Erosion (HLLE). These fish lack the coating of slime other fishes generate to shield themselves from parasites. Marine Ich presents with white spots across the fish’s body. It can also lead to lethargy and labored breathing.

The key to treatment is catching the disease early and isolating the Clown. You can then treat it with an over-the-counter anti-parasitic.

HLLE, an often fatal disease, breaks down the fish’s body, creating sores near the head or along the body. The condition results from malnutrition and stress. Clowns can recover from HLLE, but you must catch it early. Improving the fish’s nutritional intake and supplementing their diet with vitamins can restore their health and resolve the condition.

The best ways to prevent disease are by keeping your tank’s conditions within the optimal range and maintaining your fish’s happiness. Content and well-fed Clowns resist illnesses better than when they are stressed. 

Author Note: Actively monitor your fish’s mood and the tank’s water quality and quarantining new tank inhabitants can prevent the introduction of harmful parasites.

Food & Diet

Clowns are herbivores who occasionally consume invertebrate crustaceans in the wild. Varying your fish’s diet is essential for keeping them happy and nourished. They eat a variety of plant-based foods including algae that grows among your tank’s live rock. All Clowns are wild-caught, so they prefer to graze across reefs. New residents often refuse to eat when first introduced to tank life.

Experts recommend using a veggie clip, a specially designed case that holds chopped plant material and allows fish to swim by and graze. You can also try and tuck pieces of nori or seaweed beneath some of the rocks. These steps help simulate the fish’s natural feeding instincts.

Author Note: Trying various options until you find what your Clown prefers is best because nutrition is vital to their resilience and survival. You can offer chopped leafy greens and zucchini in addition to marine plants.

Although these fish are herbivores, occasionally supplementing their diets with protein is essential to keeping them healthy. It’s best to hold off on proteins until the fish is eating plants well. Once adapted, you can offer brine shrimp, mussels, mysis shrimp, and blood worms. Protein helps these fish maintain their bright colors.

Experts suggest feeding your Clown Tang twice a day. You can gauge the amount based on how much your fish consumes and alter as they acclimate to tank life. You will also need to modify feedings as your Clown grows. These fish are highly-active and well-muscled, requiring a lot of food as they develop.

Behavior & Temperament

Like most Tangs, Clowns are aggressive and territorial with members of their species. They will even lash out at similar-looking Tangs in territorial conflicts. It’s best to only keep one Tang because of their aggressive nature and high cost. While coexistence is possible, the risk of confrontations is high.

They will also attack other fish if they feel encroached upon. Generally, Tangs are docile as juveniles. Once they reach about 6 inches, their aggression starts manifesting. Their tenacity increases with age.

Despite their confrontational nature, Clowns can also exhibit shyness. When stressed, they flee to the rocks, looking for hiding spots.

Clowns will continually rove across your tank and even chase other fish. Their active lifestyle makes them voracious eaters. You must monitor feedings because they will deprive other fish of food.

Clown Tang Tank Mates

Clowns are aggressive fish but can successfully live in communal tanks. It’s best to avoid passive fish or those prone to bullying due to the Clown’s active and tenacious nature. They are also more aggressive as they age, so it’s often best to make them one of the final additions to your tank. Additionally, other Clowns and similar-looking Tangs are poor cohabitants. Good options include:


Wild Clowns live in harems, with one male protecting multiple females. Despite this social structure, they are broadcast breeders. In the wild, they spawn during full moons. Members of each sex release their genetic material, which the current sweeps away. The reproductive cells then bind, and the larva develops among floating plankton before it is mature enough to swim to a reef and begin life as a juvenile Clown.

It’s impossible to breed Clowns in a home tank. The species needs a massive area to live together, let alone spawn. Beyond that, sexing Clowns is virtually impossible because males and females are identical, though females are slightly larger.


The Clown Tang is quite high maintenance and given its aggressive behavior, it might not be the right fish for beginners. Anything is possible especially for those always willing to learn new skills, and you might be one of those since you are here reading this care guide. Just remember the large tank requirements and plant-based diet for you and your Clown to start off on the right foot.

We hope you enjoyed this guide and don’t forget to come back regularly since we are always publishing new content. For example, if you are looking to learn about other tangs you can check this Purple Tang care guide.

Thanks for visiting!


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