Foxface Rabbitfish

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.

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Is this urgent?

In a reef, stability matters more than any single target number. A parameter moving fast does more damage than a parameter sitting slightly off.

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Today

Quarantine every new animal, including corals and inverts. It is the single practice that separates a reef that lasts from a reef that restarts.

This is general guidance for a healthy adult, not a diagnosis. An exotics vet who knows your animal always overrides it — and the time to find one is before you need one.

What it really costs

Setup, monthly, first year and across a whole life, itemised and with the electricity worked out from the actual wattage. Published figures for the same animal disagree by a factor of four, so the calculator shows ranges rather than picking one.

Work out the cost of a foxface rabbitfish