Description

Obsidian Tang – Acanthurus gahhm

Overview:
The Obsidian Tang is a striking marine herbivore, known for its deep black to dark gray body with subtle blue highlights and a contrasting vibrant yellow tail. Its bold coloration and active swimming make it a standout in large reef aquariums.

Origin:
Native to the Indo-Pacific, primarily found along coral reefs and lagoons in Red Sea, East Africa, and the western Indian Ocean.

Feeding:
Primarily herbivorous – thrives on marine algae, seaweed, and spirulina-based foods, supplemented occasionally with meaty foods like mysis shrimp for balanced nutrition. Regular feeding helps maintain coloration and digestive health.

Tank Mates:
Best kept with peaceful to semi-aggressive tank mates. Avoid housing with overly aggressive tangs to minimize territorial disputes.

Aggression:
Moderately territorial – may defend feeding areas, especially in smaller aquariums, but generally compatible with other robust fish.

Experience Level:
Intermediate to advanced aquarists – requires a mature aquarium with ample swimming space, stable water conditions, and a proper herbivore diet.

Water Parameters:

Temperature: 74–80°F (23–27°C)
pH: 8.1–8.4
Salinity: 1.020–1.025
Minimum Tank Size: 125+ gallons

The Obsidian Tang is a visually striking, active herbivore, perfect for reef or large community marine tanks where a bold, dynamic fish is desired.