Lined Surgeonfish

Geographical Origin and Habitat: Tropical Indo-Pacific. Inhabits wave-swept outer reefs and shallow lagoon passages rich in corals and algae down to 15 meters. They are key ecological players on shallow reefs, keeping algae growth under control. They inhabit high-energy surge zones where wave action is intense.

Taxonomy and Morphology: Belongs to the family Acanthuridae. Reaches about 38 cm in the wild (often around 30 cm in captivity). Elliptical, laterally compressed body with venomous, sharp caudal spines. The genus Acanthurus represents the typical surgeonfish, characterized by their scalpel-like spines. Their skeletal structure is highly adapted for rapid swimming.

Social Behavior: Extremely aggressive and territorial fish. Fiercely defends large sections of algal reef, brutally attacking any competing surgeonfish. They establish dominant hierarchies in the aquarium, which must be managed carefully. They are highly active and require vast open areas.

Coloration and Sexual Dimorphism: Spectacular coloration: yellow and electric-blue longitudinal stripes bordered by thin black lines across the body. Light blue-gray belly. No visible dimorphism. Their caudal spine is venomous and can inflict painful wounds if handled carelessly. The blue and yellow striped pattern is highly warning.

Aquarium Setup: Requires a massive tank of at least 950 liters (250 gallons) with very strong water movement and excellent oxygenation. Open space is essential to reduce stress. A minimum tank length of 6 feet is strongly recommended to support their swimming habits. The aquarium must be securely covered to prevent jumping.

Diet and Feeding: Herbivore. Diet must have a very high plant content: nori, spirulina, enriched dry foods, and blanched vegetables. Grazes constantly on rocks. Provide a varied diet rich in spirulina, marine algae, and high-quality flake foods. Supplement with frozen foods to ensure protein intake.

Water Quality: Stable temperature 24-28°C (75-82°F), pH 8.1-8.4, specific gravity 1.020-1.025. Maximum skimming and filtration are indispensable to manage the bioload. Use active carbon filtration to maintain water clarity and remove chemical waste. Keep water temperature stable between 24-28°C (75-82°F).

Compatibility and Cohabitation: 100% reef-safe. Does not touch corals. However, due to its extreme aggression, it must be the only surgeonfish in the aquarium. Introduce this fish last to the aquarium to prevent it from establishing a dominant territory. Avoid tankmates with similar color patterns.

Aquarium Breeding: Reproduction is not feasible in home aquariums. Spawning pairs and groups release pelagic eggs that float in ocean currents. They are pelagic spawners, releasing their gametes into the water column where fertilization occurs. Captive rearing of larvae is exceptionally rare.

Risks and Diseases: Caudal spines are razor-sharp and contain venom glands. Exercise extreme caution during handling. Highly prone to parasites. They are highly susceptible to skin parasites under stress, requiring quarantine procedures. Ensure you wear thick gloves if catching the fish.