Achilles Tang Profile

Achilles Tang - A Difficult to Keep Surgeonfish

Acanthurus achilles
Achilles Tang (Adult). Photo couresty of Keoki and Yuko Stender

Scientific Name:

Acanthurus achilles (Shaw, 1803)

Other Common Names:

Achilles Surgeonfish.



Average Size:

9.4 inches (24 cm).

Characteristics and Compatibility:

One of the more demanding surgeonfish of the Acanthuridae Family, the Achilles Tang requires much attention. It is highly susceptible to contracting ich, and can have problems with HLLE. It can be aggressive towards other surgeonfishes, especially those of its own kind.

Large adult specimens in particular fight terribly if not given lots of space to keep them apart. With the possible exception of providing are very large system with more than ample room to swim around and plenty of places to hide, this fish is best kept singly. Often hard to acclimate.

In the wild, the Achilles Tang greatly prefers the highly oxygenated waters of the surge zones in and around the reef with plenty of holes and caves to retreat to when it feels threatened.


The Achilles Tang, like other Surgeonfish, is pelagic (a "free-spawner"), spawning in groups. The female ejects her small eggs in the water column after which the male swims over and through the egg "cloud", fertilizing as he goes. The female produces hundreds of eggs at a time several times per year, usually in the spring and summer months.

The clear fertilized eggs float to the surface and join the stream of plankton where the larva feed and develop into miniature adults, lacking the orange/red dot at the base of the tail.

The juvenile Achilles eventually descend onto the reef where they take refuge and grow to maturity.

An Achilles/Goldrim Hybrid Tang occurs on occasion in the wild and is quite a sight to see.

Diet and Feeding:

The Achilles is primarily a herbivore that will graze on filamentous micro and some types of smaller fleshy macroalgae.

Often a difficult fish to feed, it should be fed frozen and dried fares suitable for herbivores that contain marine algae and Spirulina (blue-green algae). Zucchini, broccoli, leaf lettuce, and nori (dried seaweed) can be offered to supplement its diet. Should be fed at least 3 times a day.


Requires lots of room to swim around, and plenty of places to hide. A constant grazer, this fish is best kept in a well established aquarium with a hardy growth of marine algae to graze on at its leisure.

Suggested Minimum Tank Size:

100 gallons (379 L).

Reef Tank Suitability:

Considered safe, but an individual may decide to pick at large polyped stony corals if not well fed. Being a herbivore, the Achilles Tang is great for keeping a number of different species of algae under control in a reef tank.

Guide Notes:

The Achilles Tang is one of THE most challenging fish we have collected, shipped, and cared for. It is sensitive to ammonia poisoning, is an extremely difficult species to handle, and therefore should only be kept by an experienced aquarist.

It sounds silly, but this a fish that seems to break out with ich if you even look at it the wrong way. The Achilles Tang can be a picky eater, and may not readily accept foods offered.

For this reason, and because they seem to have gotten rare and hard to find, it is best to ask to see this fish eating before you buy one.

As with any Surgeonfish, the Achilles Tang comes equipped with a pair of very deadly "spurs" which can inflict a serious wound, not only to a distracted aquarist, but also to other fish in an aquarium. Back when we were collecting tropical fish in Hawaii, we had a few special locations that we could go to collect Achilles Tangs. Since we were going to have to keep the Achilles in a confined area (the holding tank) on the boat for the trip back to the boat launch and then home to our holding system, we would clip the tips of the spurs with a pair of nail clippers to keep the fish from damaging each other (and us when we were handling them).