One-spot foxface (Siganus unimaculatus) care guide

Group
Marine fish
Other names
Blotched foxface, Blackblotch foxface
Family
Siganidae (rabbitfishes)
Origin
Central Indo-Pacific in two separate populations: Ryukyu and Ogasawara Islands to the Philippines, and the Rowley Shoals off north-western Australia; shallow reefs and lagoons to 14 m.
Water
saltwater
Maximum size
18 cm
Temperature
24–27°C
pH
8.1–8.4
Hardness
Salinity SG 1.023–1.026
Minimum tank
350 litres
Care level
intermediate
Temperament
peaceful
Reef safe
with_caution

Care

Tank: an estimated minimum of about 350 litres (our estimate from its 18 cm list size; the article gives 20 cm), with rockwork and open swimming space. Water: 24–27 °C, pH 8.1–8.4, salinity SG 1.023–1.026. These are general marine aquarium figures for a tropical species, not species-specific values from the sources. Keep nitrate low and oxygen high. Behaviour: adults and subadults form lasting pairs, including same-sex pairs; juveniles may gather in large groups. Told from the common foxface by the dark blotch on each side. Sold in the aquarium trade and also caught for food. Safety: the fin spines carry venom glands. A sting is painful but rarely dangerous. Net carefully, never hold the fish by hand, and get medical advice if stung. Conservation: assessed by the IUCN (2019); the category is not given in the article. Sources: Wikipedia, List of marine aquarium fish species (en.wikipedia.org/wiki/Listofmarineaquariumfishspecies); Wikipedia (en.wikipedia.org/wiki/Siganusunimaculatus). Checked October 2026.

Diet

A herbivore that grazes seaweeds. Feed marine algae (nori, macroalgae) daily, plus herbivore flake or pellets and occasional frozen mysis.

Breeding

Spawning in the wild appears to happen around the new moon, when large groups gather and lay eggs on the bottom. Not known to be bred by hobbyists.

Compatibility and tank mates

Peaceful with most fish of similar size; keep singly or as a pair. Reef safe with caution: it may pick at soft corals, zoanthids or fleshy LPS corals when hungry.

Last updated 8 October 2026. Community-edited care guide on Aquatic-Auctions.

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