Aquarium 450L+ / 120gal+, at least 150cm (5ft) long
Social needs
One per tank; peaceful with dissimilar fish
Diet
Herbivore-leaning omnivore (algae, nori, veg)
Time
Daily feeding; weekly testing and water changes
Cost
High
Overview
The Foxface Rabbitfish is a bright yellow grazer with a pointed, fox-like snout and a bold black-and-white banded face.
It reaches around 24cm (9.5in) as an adult, so it is a genuinely large fish that outgrows midsize tanks.
Its defining trait is defensive: the 13 dorsal spines, plus the anal and pelvic spines, are venomous, and a sting is sharply painful, so this is a fish you plan handling around.
Compared with the tangs it is often bought alongside, the Foxface is hardier, thicker-skinned, and far less territorial, which makes it one of the more forgiving large marine herbivores.
It is still not a beginner fish: the tank-size requirement is real, and nearly all stock is wild-caught from the Western Pacific because captive breeding is not yet commercially established.
One quirk catches new keepers out: at night or when stressed it switches to a blotchy brown camouflage pattern.
That mottling is normal and reversible, not a disease.
Housing
Provide at least 450L (120 gal) with a tank length of 150cm (5ft) or more, because this is an active, open-water grazer that cruises the full run of the aquarium; a 6ft tank suits an adult better long term.
Keep temperature 24-27°C (75-80°F), salinity 1.024-1.026, pH 8.1-8.4, and nitrate low with strong flow and good oxygenation.
Aquascape with generous rockwork for grazing and a cave it can retreat to, while leaving clear swimming lanes along the front.
A tight-fitting lid matters, since a startled Foxface can jump.
Add it to an established tank with some natural algae growth rather than a newly cycled system, and quarantine it like any new marine fish.
Plan the maintenance routine so you never need to grab it by hand: use a container to guide it rather than a net pressed against venomous spines.
Diet
The Foxface is a herbivore-leaning omnivore whose diet must stay green.
Offer dried marine algae (nori) on a clip daily, alongside quality herbivore pellets and occasional herbivore frozen foods.
It grazes constantly and famously mows down hair algae, and many individuals will even pick at bubble algae that other fish ignore.
Underfeeding is the classic mistake with this species.
A hungry Foxface is the one that starts nipping zoanthids and fleshy LPS corals, which is why it is rated reef-safe only with caution.
Keep it well fed with several small algae-based feedings and it generally leaves corals alone.
A meaty, protein-heavy diet is the other error: it dulls colour and undermines long-term health, exactly as it does in tangs.
Health
The Foxface has a thick slime coat and is noticeably more resistant to marine ich than the tangs on this site, but resistant is not immune, so quarantine every new arrival.
Watch newly imported fish for a pinched belly, which signals starvation in the supply chain and calls for immediate, frequent algae feedings.
As with other marine herbivores, chronic poor diet and water quality can lead to head-and-lateral-line erosion, so keep nitrate low and the diet algae-rich.
Persistent dark mottling during the day, combined with hiding and refusal to eat, is the signal that something is actually wrong, as opposed to the normal night-time colour change.
Keeper safety is part of the health picture here.
A sting from the dorsal spines causes intense pain and swelling; immerse the wound in hot (not scalding) water and seek medical advice if symptoms spread or you have any allergic reaction.
Temperament
The Foxface is calm and peaceful toward almost everything it does not resemble, and because it is not a tang it usually coexists with a Yellow Tang or other surgeonfish without the turf wars tangs wage on each other.
It spends the day openly grazing and cruising, raising its venomous dorsal fin and flashing mottled colour only when it feels threatened.
Keep one per tank as the standard rule, since two Foxfaces will squabble unless they arrive as a bonded pair in a very large system.
It ignores shrimp and small fish, so it fits over communities of gobies, blennies, and cardinalfish without risk.
Its defence is entirely passive: it never attacks tankmates with its spines, but slow-moving fish that blunder into a raised fin can be stung, and so can a keeper's careless hand during aquascaping.
A good fit for
Keepers with an established 120-gallon-plus system
Reef tanks fighting hair or bubble algae
Communities that already include a tang
Intermediate marine keepers stepping up in size
Aquarists wanting a hardier alternative to tangs
Common mistakes to avoid
Venomous dorsal spines - never hand-catch or net carelessly
Tanks under 120 gallons / 5ft cramp an adult
Underfed individuals nip zoanthids and LPS corals
Panicking over normal brown night-time mottling
Nearly all stock is wild-caught - choose suppliers carefully
Intermediate
Intermediate
Intermediate
Intermediate
Intermediate
Intermediate