Saltwater Fish
Acanthurus tristis
Acanthurus tristis - Indian Mimic Surgeonfish

Acanthurus tristis (Indian Mimic Surgeonfish)

Species Description…

Scientific Name: Acanthurus tristis
Common Name: Indian Mimic Surgeonfish
Species Group: Surgeonfish
Habitat: Reef Safe
Care Level: Intermediate
Temperament: Semi-aggressive
Diet Type: Herbivore
Role in Aquarium: Community Fish
Max Fish Length: 10 (inches)
Min Aquarium Size: 125 (gallons)
Native Range: Indian Ocean, including the Andaman Sea and waters around Sri Lanka and Indonesia

Overview

  • Native to the Indian Ocean, commonly found in coral reef environments.
  • Recognized for its ability to mimic juvenile angelfish for protection against predators.
  • Changes coloration as it matures, transitioning from bright yellow to a darker, more muted shade.
  • A fascinating and adaptable species popular among marine aquarists.

Feeding

  • Herbivorous diet, primarily grazing on marine algae.
  • Requires a diet rich in plant-based foods, including seaweed, spirulina, and herbivore pellets.
  • Supplementing with fresh vegetables or dried seaweed supports optimal health.
  • Frequent small feedings encourage natural grazing behavior and sustain energy levels.

Habitat

  • Commonly found in coral reefs, reef slopes, and rocky coastal zones.
  • Prefers stable water conditions with moderate to strong water flow.
  • Requires an aquarium with open swimming space and rock formations for grazing.
  • Thrives in environments that mimic its natural surroundings with strong water movement.

Fish Care

  • Optimal water temperature: 74-82°F (23-28°C).
  • Ideal pH level: 8.1-8.4, with a specific gravity of 1.020-1.025.
  • Prone to stress-related illnesses such as marine ich; requires pristine water conditions.
  • Best introduced into a mature aquarium with excellent filtration and strong water flow.
  • Providing ample swimming space and hiding areas supports long-term health.

Compatibility

  • Generally peaceful but may become territorial towards other tangs.
  • Compatible with peaceful tank mates such as wrasses, clownfish, and angelfish.
  • Should not be housed with overly aggressive species that may cause stress.
  • Does well in a community reef setup with proper space and hiding spots.

Aquarium Behavior

  • Active swimmer, constantly patrolling the aquarium and grazing on algae.
  • Can display territorial tendencies, particularly in confined spaces.
  • Often interacts with other tank mates but may establish dominance over time.
  • Providing an environment with live rock and algae supports natural behaviors.