Japanese Surgeonfish
Acanthurus japonicus
This fish has an oval, laterally compressed body, dark blue to violet with a broad yellow stripe on the back and a bright yellow caudal fin. A sharp white spine is present on the caudal peduncle, typical of surgeonfish. Juveniles are duller. It grows up to 21 cm. It is diurnal and grazes on algae on rocks. It can become territorial towards conspecifics. In an aquarium, it requires good water flow and high water quality.
Recommended parameters
| Parameter | Recommended range |
|---|---|
| Temperature | 24–28 |
| pH | 8.1–8.4 |
| GH | 8–12 |
| KH | 8–12 |
| Salinity | 1.02–1.025 |
| NO₃ | ≤ 20 |
| PO₄ | ≤ 0.1 |
Care
Care notes
Maintain temperature 24-28°C, pH 8.1-8.4, salinity 1.020-1.025. A minimum tank size of 300 liters is recommended for one specimen. It is herbivorous: feed with dried algae (nori), spirulina-based flakes, and blanched vegetables. Avoid excess animal protein. It can coexist with other peaceful fish but may be aggressive towards other surgeonfish. Provide hiding places and open swimming space. A protein skimmer is essential. Keep parameters stable with nitrates <20 mg/L and phosphates <0.1 mg/L. Moderate lighting and moderate to strong water flow are appreciated.