Unicorn tang (Naso unicornis) care guide

Group
Marine fish
Other names
Short-nose unicornfish, Kala
Family
Acanthuridae (surgeonfishes, tangs and unicornfishes)
Origin
Tropical Indo-Pacific, where it is very common; inshore reefs with waves or strong surge, usually in the top 12 m.
Water
saltwater
Maximum size
70 cm
Temperature
24–27°C
pH
8.1–8.4
Hardness
Salinity SG 1.023–1.026
Care level
expert
Temperament
semi_aggressive
Reef safe
yes

Care

Tank: at up to 70 cm (the largest recorded fish weighed 5.8 kg) and living in surge zones, this is a fish for public-aquarium-sized systems, not home aquaria. Water: our sources give no species-specific figures, so the values shown (24–27 °C, pH 8.1–8.4, SG 1.023–1.026) are general marine aquarium guidance, not species-specific. Like other surgeonfish it needs well-oxygenated water with strong flow and stable quality. Behaviour: often solitary, but also in small groups or mixed schools. Males have much larger tail spines and slightly longer horns and tail streamers than females. Two blue blades sit on each side of the tail base; never handle it by hand. Trade and status: occasionally traded. Assessed by the IUCN (2012). Not CITES-listed. In Hawaii it eats the invasive seaweed Gracilaria salicornia, though its droppings can spread live fragments. Selling: our policies require the adult size and long-term tank needs to be stated clearly in the listing. Large fish must travel by a specialist live-animal courier (see the Livestock shipping guide). Sources: Wikipedia, List of marine aquarium fish species (en.wikipedia.org/wiki/Listofmarineaquariumfishspecies); Wikipedia (en.wikipedia.org/wiki/Nasounicornis). Checked October 2026.

Diet

A herbivore eating coarse or leafy brown and red seaweeds, one of few reef fish that eats fleshy seaweed. In captivity it needs large amounts of macroalgae and nori plus spirulina-based foods.

Breeding

Our sources give no breeding information; not bred in aquaria.

Compatibility and tank mates

Safe with corals but will eat ornamental seaweeds. Only for very large systems with other large fish.

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

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