Dussumier's Surgeonfish

Geographical Origin and Habitat: Indo-Pacific: widely distributed from the coasts of East Africa and South Africa to the Hawaiian and Line Islands, reaching north to southern Japan and south to the Great Barrier Reef. It inhabits deep outer reefs, rocky slopes, and coral barriers down to 130 meters, often associated with reefs rich in benthic algae.

Taxonomy and Morphology: Belongs to the family Acanthuridae, genus Acanthurus. Features a tall, oval, laterally compressed body, with a small terminal mouth equipped with specialized teeth for scraping rocks. In nature, it can reach a remarkable maximum length of 54 centimeters, though it remains significantly smaller in captivity.

Social Behavior: Solitary or gregarious species that gathers in large schools in the wild. In the aquarium, it shows strong territoriality towards other surgeonfish (particularly conspecifics or fish with similar shapes and colors). It moves constantly in open water, swimming vigorously throughout the tank.

Coloration and Sexual Dimorphism: Brownish or grey-olive body finely decorated with very thin wavy bluish lines. Characterized by a prominent yellow band across the eyes, golden opercula, and a bluish caudal fin covered with small black dots. The retractable caudal spine is white. There is no visible sexual dimorphism.

Aquarium Setup: Due to its large size and energetic swimming, it requires a huge aquarium, preferably starting from 800-1000 liters. The tank must feature ample open swimming space and a solid rock structure to provide night shelters without blocking water flow. Strong water movement is indispensable.

Diet and Feeding: Primarily herbivorous. Feeds mainly on diatoms, benthic microalgae, and organic debris. In the aquarium, it must receive plant-based food several times a day: fresh nori sheets, spirulina, specific dry foods enriched with vitamins, and small frozen foods (brine shrimp and mysis) to vary the diet.

Water Quality: Requires impeccable marine water quality. Temperature must be between 24 and 28 °C, stable pH between 8.1 and 8.4, and density at 1.022-1.025. An oversized filtration system with a highly efficient protein skimmer and stable dissolved oxygen levels is fundamental.

Compatibility and Cohabitation: Aggressive towards other surgeonfish, especially of the same genus. Can cohabit peacefully with active and robust reef fish (such as wrasses, anthias, large angelfish, or damselfish). It is reef-safe and does not disturb hard or soft corals and large invertebrates.

Aquarium Breeding: Oviparous reproduction with spawning in open waters. They form pairs or spawning groups that release gametes into the water column. The larvae undergo a complex planktonic phase (called acronurus). There are no documented cases of successful breeding and rearing in home aquariums.

Risks and Diseases: Highly sensitive to skin diseases such as marine white spot (Cryptocaryon irritans) and Oodinium, especially during the acclimation phase. It is essential to quarantine the fish before introducing it to the display tank and to maintain excellent water quality at all times.