Free reef fish guide
The tang fish kept in reef tanks are surgeonfish from five main genera: Zebrasoma (Yellow, Purple, Scopas, Sailfin), Acanthurus (Powder Blue, Achilles, Clown), the small bristletooth Ctenochaetus (Kole, Tomini), Paracanthurus (the Blue or Hippo Tang) and Naso (unicornfish). Most need a tank at least 4 ft (120 cm) long, and the larger species 6 ft or more.
This free guide compares 18 commonly kept tangs. Filter by adult size, tank length, reef safety, hardiness, ich risk, aggression, diet and price, open a species card, or let the picker check which tang fits your tank.
Visual guide
Sizes, tank minimums and price bands are conservative hobby guidance, not rules. Tangs need swimming length more than volume.
Showing 18 of 18 tangs
Zebrasoma flavescens
Also called: Yellow Sailfin Tang, Hawaiian Yellow Tang
Ctenochaetus strigosus
Also called: Yellow-eye Tang, Goldring Bristletooth, Kole Yellow-eye
Ctenochaetus tominiensis
Also called: Tomini Bristletooth, Orange-tip Bristletooth, Flame Fin Tang
Zebrasoma scopas
Also called: Brown Tang, Twotone Tang, Brushtail Tang
Zebrasoma xanthurum
Also called: Yellowtail Tang, Yellowtail Surgeonfish
Zebrasoma gemmatum
Also called: Spotted Tang, Gemmatum Tang
Zebrasoma velifer
Also called: Pacific Sailfin Tang, Desjardini Tang, Red Sea Sailfin Tang
Paracanthurus hepatus
Also called: Hippo Tang, Regal Tang, Palette Tang
Acanthurus leucosternon
Also called: Powder Blue Surgeonfish, PBT
Acanthurus japonicus
Also called: Japonicus Tang, Gold Rim Tang, White-faced Surgeonfish
Acanthurus achilles
Also called: Red-tail Tang, Achilles Surgeonfish
Acanthurus lineatus
Also called: Lined Surgeonfish, Striped Surgeonfish, Pajama Tang
Acanthurus triostegus
Also called: Convict Surgeonfish, Manini
Ctenochaetus hawaiiensis
Also called: Hawaiian Bristletooth, Black Surgeonfish
Acanthurus pyroferus
Also called: Chocolate Tang, Mimic Surgeonfish, Half Black Mimic Tang
Acanthurus olivaceus
Also called: Orangeband Surgeonfish, Orange Epaulette Tang
Naso lituratus
Also called: Lipstick Tang, Orangespine Unicornfish, Blonde Naso (N. elegans)
Naso vlamingii
Also called: Bignose Unicornfish, Vlaming's Unicornfish
Tang picker
Verdict
Tangs that could fit
13 tangs could fit; up to 2 tangs for a 6 ft tank.
#1 · Good fit
Tomini Tang
Ctenochaetus tominiensis
#2 · Good fit
Kole Tang
Ctenochaetus strigosus
#3 · Good fit
Yellow Tang
Zebrasoma flavescens
#4 · Good fit
Scopas Tang
Zebrasoma scopas
#5 · Good fit
Convict Tang
Acanthurus triostegus
#6 · Good fit
Sailfin Tang
Zebrasoma velifer
The picker uses fixed, conservative rules from common hobby guidance, not a guarantee. Individual fish vary.
Tangs, surgeonfish and unicornfish all belong to the family Acanthuridae. FishBase lists 85 species in 6 genera; five genera supply almost every tang in the aquarium trade.
Sailfin tangs: tall, disc-shaped bodies and big fins. Algae grazers. Two Zebrasoma usually fight unless the tank is very large.
Examples: Yellow, Scopas, Purple, Sailfin, Gem
The largest genus of surgeonfish: oval bodies, fast open-water swimmers that need long tanks. Several are ich-prone.
Examples: Powder Blue, Powder Brown, Achilles, Clown, Convict, Mimic, Orange Shoulder
Bristletooth tangs: comb-like teeth for grazing detritus and algae film off rock. Smallest and most reef-friendly tangs.
Examples: Kole, Tomini, Chevron
One species, the Blue (Hippo) Tang. Eats plankton as well as algae and is prone to ich.
Examples: Blue (Hippo / Regal) Tang
Unicornfish: long bodies, often a forehead bump or horn. Large, peaceful-ish, and need very long tanks.
Examples: Naso (Lipstick), Blonde Naso, Vlamingi
Tangs are fast, open-water swimmers, so tank length matters more than gallons. Common hobby guidance:
As a rough rule, plan on one tang per 4 to 6 ft tank, two in a 6 ft tank and three in 8 ft+. These are conservative hobby figures, not laws; a tank that meets them still needs stable water and enough algae to graze.
For a 4 ft reef, the Kole and Tomini bristletooth tangs are the best fits: they stay around 6 in (15 cm), are hardy and graze film algae without bothering corals.
The Yellow Tang is the other classic 4 ft tang. In a tank shorter than 4 ft there is no good tang; a Lawnmower Blenny and snails handle algae, and the clownfish guide has small-tank stars.
The Clown Tang is usually named the most aggressive tang, followed by the Purple, Powder Blue and Achilles.
Most tang fights are between tangs of the same genus or body shape, for example a Yellow and a Purple (both Zebrasoma) or a Powder Blue and an Achilles (both Acanthurus). Keep one tang per genus, add the most aggressive one last, or add several tangs together in a 6 ft+ tank. Check the rest of your stock with the fish compatibility checker.
Mostly yes. Tangs are herbivores that graze algae and do not eat corals, which is why reef keepers add them for algae control. A few individuals pick at zoanthids, fleshy LPS or clam mantles, most often Blue (Hippo), Clown and Achilles Tangs. Naso Tangs eat brown macroalgae, so they will also eat ornamental macroalgae in the display.
Feed tangs dried seaweed (nori) every day, plus herbivore pellets or frozen foods. A hungry tang is more likely to sample corals, and a well-fed one has better colour and resistance to disease. The reef algae ID guide shows which algae tangs graze.
Every surgeonfish has a sharp, blade-like spine on each side of the tail base (the caudal peduncle); Naso species have fixed plates. That "scalpel" is where the name surgeonfish comes from, and a startled tang can cut a hand or another fish with it.
Tangs are among the fish most likely to bring marine ich (Cryptocaryon irritans) or marine velvet into a tank. The Powder Blue, Achilles and Blue (Hippo) Tangs are especially susceptible. Quarantine every new tang in a separate tank for several weeks before it goes in the display.
This guide gives no medication or dosing advice. Plan a quarantine tank with the quarantine tank planner and read the ich and hyposalinity planner if a fish shows white spots.
| Confused pair | How to tell them apart |
|---|---|
| Kole vs Tomini vs juvenile Chevron | Kole: brown with fine lines and a gold ring around the eye. Tomini: dark brown with a yellow-orange tail and fin edges. Juvenile Chevron: bright orange with purple chevron lines (adults turn dark brown). |
| Powder Blue vs Powder Brown | Powder Blue: pale blue body, black face, white throat, yellow dorsal fin. Powder Brown (A. japonicus): brown-grey with a white band from eye to mouth; the Whitecheek (A. nigricans) has only a small white patch. |
| Mimic Tang vs dwarf angelfish | Juvenile Mimic Tangs copy Half-black, Lemonpeel or Eibl's angelfish. Look at the tail: a tang has a crescent tail and a spine at its base; a dwarf angel has a rounded tail and a spine on the gill cover. |
| Yellow vs Gem Tang | Same Zebrasoma shape, but the Yellow Tang is yellow all over; the Gem Tang is dark with white spots and only the tail is yellow. |
| Naso Tang: Pacific vs Blonde | Naso lituratus has a black dorsal fin; the Blonde Naso (N. elegans, Indian Ocean) has a yellow dorsal fin. Care is the same. |
Step 1
Type the display tank length in inches or centimetres; length is the main limit for tangs.
Step 2
Type the water volume in gallons or liters.
Step 3
Choose reef or fish only, and your experience level.
Step 4
Select any tangs already in the tank, and optionally a tang you want to add.
Step 5
Review the ranked tangs with reasons and warnings: same-genus conflicts, aggressive tangs, ich risk and too many tangs. Tanks under 4 ft get a no-tang verdict.
Most tangs need a tank at least 4 ft (120 cm) long, and the common hobby minimum is about 75 gallons for the smallest species such as the Kole, Tomini and Yellow Tang. Larger, faster tangs such as the Blue (Hippo), Powder Blue, Achilles, Clown and Naso need 6 ft (180 cm) or more, and the Vlamingi needs 8 ft. Length matters more than volume because tangs are active open-water swimmers.
There is no tang for a truly small tank: under 4 ft long, the honest answer is no tang. For a 4 ft tank, the Kole and Tomini Tangs (bristletooth tangs that stay around 6 in) and the Yellow Tang are the usual choices. All three are hardy and coral safe. Keep just one tang in a 4 ft tank.
The Clown Tang (Acanthurus lineatus) is widely considered the most aggressive aquarium tang, followed by the Purple, Powder Blue and Achilles Tangs. Same-genus tangs, especially two Zebrasoma such as a Yellow and a Purple, fight the most. Add aggressive tangs last, or add several tangs at the same time in a large tank.
Most tangs are reef safe: they graze algae and do not eat corals. Bristletooth tangs (Kole, Tomini, Chevron) are among the most reef-friendly fish. A few individuals, notably some Blue (Hippo), Clown and Achilles Tangs, nibble zoanthids, fleshy LPS or clam mantles, and Naso Tangs eat ornamental macroalgae.
FishBase lists 85 species in the surgeonfish family Acanthuridae, in 6 genera, which includes tangs, surgeonfish and unicornfish. Around 15 to 20 species are common in reef tanks, mainly from Zebrasoma, Acanthurus, Ctenochaetus, Paracanthurus and Naso.
Every species card links to its FishBase page; wild maximum lengths are FishBase figures (TL total, SL standard or FL fork length). Tank sizes, hardiness, ich risk, aggression and price bands are conservative hobby guidance, not measurements. This guide gives no medication or dosing advice.
Check that your tang gets along with the rest of your fish.
See how a tang affects your tank's bioload.
Set up a quarantine tank before a new tang goes in the display.
Plan ich treatment for ich-prone tangs.
Pick a clownfish for a tank that is too small for a tang.
Identify the algae a tang will and will not graze.
Measure your tank's volume for the picker.