The Lieutenant Tang, also widely known as the Tennent Tang or Vampire Tang, is a sleek and highly dynamic surgeonfish native to the tropical Indian Ocean. Recognized by its distinct black shoulder markings that resemble military rank insignia (which often merge into a single solid bar as it matures), it also boasts a vibrant, blue-ringed caudal spine near its crescent tail. As an active, constant swimmer, it plays an invaluable functional role in reef displays by continuously grazing on unwanted filamentous algae and film algae across live rockwork. While generally peaceful toward non-tang tankmates, it requires a large aquarium with robust water movement, high oxygenation, and plenty of open horizontal swimming space to thrive long-term.
| Parameter |
Specification |
| Scientific Name |
Acanthurus tennentii |
| Care Level |
Moderate |
| Temperament |
Semi-Aggressive (Territorial toward other surgeonfish) |
| Reef Safe |
Yes |
| Diet |
Herbivore (Nori, spirulina, algae wafers, marine flakes, mysis) |
| Min. Tank Size |
700 Litres / 180 Gallons |
| Max. Size |
Up to 25 cm |
| Water Temperature |
24°C – 26°C |
| pH Range |
8.1 – 8.4 |
| Specific Gravity |
1.020 – 1.025 |