Japanese Surgeonfish (Acanthurus japonicus)

Japanese Surgeonfish Acanthurus japonicus
Name	Japanese Surgeonfish
Name Lat.	Acanthurus japonicus
Family	Surgeonfishes
Family lat.	Acanthuridae
Order	Surgeonfishes
Order lat.	Acanthuriformes
Origin	Indo-West Pacific
Habitat	Lagoons, seaward reefs
Diet	Herbivore
pH	8.1-8.4
Hardness	8-10 °KH
Behavior	Semi-aggressive
Keeping	Individual
Reef Compatible	With caution
Care Level	Difficult
Life Span	8-10 years
Protection	No
Metric Units
Size	20 cm
Temperature	22-28 °C
Salinity	33-36 ‰
Aquarium	~ 600 l
US Units
Size	8"
Temperature	72-82 °F
Salinity	1.020-1.025 sg
Aquarium	~ 150 gal

Distribution and habitat

The range of Acanthurus japonicus is the Indian Ocean and the western Pacific, from southern Japan through the Philippines to Indonesia, where it lives mostly in lagoons and on outer reefs up to 20 m depth.

Maintenance

They require a well-structured aquarium with plenty of swimming space and a reef structure (hiding, resting and retreat possibilities) with living stones which they can graze on and which act like a biological filter. Only lime-rich, heavy metal-free sands, gravels, stones or sea sand of various grain sizes may be used as substrate

Filters, skimmers and heaters are necessary to ensure water quality, as well as pumps to simulate tides, swells and bottom currents. Lighting must correspond to the species-appropriate day-night rhythm of the animals

Salinity: 33-36 ‰	pH value: 8.1-8.4
Carbonate hardness: 8-10 °KH	Nitrate content: 2-8 mg/l
phosphate content: 0.01-0.1 mg/l	nitrite content: 0.0-0.05 mg/l

For salinity, an average value should be aimed for, which may only vary slightly by +/- 0.5 ‰. Ammonia and ammonium must not be measurable. Special attention must be paid to constantly good water quality.

Diet

They feed mainly on plant food, such as algae and seaweed. The change of diet does not always succeed without problems. The diet consists mainly of commercially available algae and kelp (e.g. nori, caulerpa, kelp) supplemented with high-quality flake or granulated food for herbivores or a commercially available vitamin-enriched frozen special food mix for herbivores. Live or frozen food such as artemia, krill or mysis should only be offered in small quantities. Plant food strengthens the immune system and reduces aggression. Fine coral sand serves as a digestive aid for them

It is recommended to feed small portions several times a day. Regular and varied feeding promotes health and prevents deficiency symptoms.

Behaviour and compatibility

It is recommended to keep them individually. They behave very territorial within the species and towards other surgeonfishes. Keeping them in pairs is only possible in a much larger and richly structured tank. Towards other fishes they behave peacefully.

Sex dimorphism

There are no known external distinguishing characteristics.

Reproduction and breeding

There are no known reports of successful breeding in the aquarium.

Important

A characteristic feature of surgeonfishes is the scalpel located on either side of the caudal peduncle, which can be unfolded from its pocket by bending the body.

As coral reef dwellers, they should not be maintained in a fish-only aquarium. With varied and frequent feeding, they can be maintained in challenging coral tanks without serious coral encroachment.

If different species are kept together, care should be taken to match the fish in terms of water quality and temperature requirements, as well as their social behavior, and to ensure that the setup meets the needs of all species kept together. New fish to be introduced must be acclimated slowly to the water in the aquarium.

Further literature can be found in your pet store.

References

Text: Werner Winter; Image: Franz Lowak

Source: KUITER, DEBELIUS (2007): Atlas der Meeresfische: Die Fische an den Küsten der Weltmeere, Kosmos Verlag; ENGELMANN (2005): Zootierhaltung - Tiere in menschlicher Obhut: Fische, Verlag Harri Deutsch

• Gemäß § 21 Abs. 5 Tierschutzgesetz idgF