How related are they?
Same genus, Acanthurus (Acanthurus surgeonfishes): very close cousins
They split at the species level: the Achilles Tang belongs to Acanthurus achilles (Achilles Tang), the Powder Blue Tang to Acanthurus leucosternon (Powder Blue Tang).
Find the Achilles Tang on the tree · Find the Powder Blue Tang on the tree
Family lines, side by side
Highlighted rows are groups both animals belong to. The marked row is where their lines go separate ways.
| Rank | Achilles Tang | Powder Blue Tang |
|---|---|---|
| Kingdom | Animalia Animals | |
| Phylum | Chordata Chordates | |
| Subphylum | Vertebrata Vertebrates | |
| Infraphylum | Gnathostomata jawed vertebrates | |
| Parvphylum | Osteichthyes bony fishes | |
| Gigaclass | Actinopterygii ray-finned fishes | |
| Superclass | Actinopteri | |
| Class | Teleostei Teleost fishes | |
| Order | Acanthuriformes Surgeonfishes, angelfishes and kin | |
| Family | Acanthuridae Surgeonfishes and tangs | |
| Genus | Acanthurus Acanthurus surgeonfishes | |
| Species split | Acanthurus achilles Achilles Tang | Acanthurus leucosternon Powder Blue Tang |
Care, side by side
| Fact | Achilles Tang | Powder Blue Tang |
|---|---|---|
| Type | Fish · Tang | Fish · Tang |
| Care level | Expert | Expert |
| Reef safe | Yes | Yes |
| Temperament | Semi-aggressive | Semi-aggressive |
| Diet | Herbivore | Herbivore |
| Favorite foods | Dried seaweed (nori) on a clip, Algae-based pellets, Spirulina-enriched brine shrimp or mysis | Dried marine algae sheets (nori, red and green seaweed) on a clip, Frozen herbivore formulas, Spirulina and algae-based flakes and pellets |
| Max size | 9.4 in (24 cm) | 9 in (23 cm) |
| Minimum tank | 180 gal | 180 gal |
| Temperature | 72–78 °F | 72–78 °F |
| Salinity (SG) | 1.020–1.025 | 1.020–1.025 |
| pH | 8.1–8.4 | 8.1–8.4 |
| Nitrate | — | 0–30 ppm |
| Lifespan | Not documented in the sources we checked; no published longevity study or reliable captive lifespan figure was found. | Poorly documented. Many wild-caught fish die within weeks of import from disease and shipping stress; fish that settle in commonly live about 7-10 years or more according to hobby care guides. No published age study for this species was found. |
| Breeding | Not achieved | Not achieved |
| Conservation (IUCN) | Least Concern | Least Concern |