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 Convict Tang to Acanthurus triostegus (Convict Tang).
Find the Achilles Tang on the tree · Find the Convict 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 | Convict 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 triostegus Convict Tang |
Care, side by side
| Fact | Achilles Tang | Convict Tang |
|---|---|---|
| Type | Fish · Tang | Fish · Tang |
| Care level | Expert | Moderate |
| 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 seaweed (nori) on a clip, Spirulina and herbivore flakes or pellets, Frozen herbivore foods |
| Max size | 9.4 in (24 cm) | 10.6 in (27 cm) |
| Minimum tank | 180 gal | 125 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 |
| Lifespan | Not documented in the sources we checked; no published longevity study or reliable captive lifespan figure was found. | Not documented in the sources we checked; no published longevity study or reliable captive lifespan figure was found. |
| Breeding | Not achieved | Very hard |
| Conservation (IUCN) | Least Concern | Least Concern |