Foxface Rabbitfish — Siganus vulpinus

Efficient algae grazer. Generally peaceful.

Quick facts

• Size: 20–24 cm

• Temperament: Peaceful; can display to rivals

• Reef-safe: “With caution” — mostly fine, occasional nipping of softies/LPS if underfed

• Minimum tank: 350–450 l / 90–120 gal

• Special: Dorsal spines are venomous

Aquarium

• Space: Long tank with open swimming lanes and rock for grazing/hiding.

• Water: pH 8.1–8.4, salinity 1.025–1.026, temp 24–26 °C; NH3/NO2 0, NO3 <20 ppm, PO4 <0.1 ppm.

• Flow: Moderate.

• Cover: Recommended; can bolt when startled.

• Lighting: Normal reef lighting; may “pajama” camo at night or under stress.

Diet

• Primary: Macro and film algae, including hair algae.

• Daily feed: Nori/seaweed sheets, spirulina pellets, herbivore flakes; offer some mysis/roe for variety.

• Goal: Keep well fed to reduce coral nipping.

Behavior & compatibility

• Community: Good citizen with most peaceful to semi-assertive fish.

• Conspecifics: One per tank unless a proven pair in a very large system.

• Corals/inverts: Usually safe; monitor with fleshy LPS, zoas, and clams.

Acclimation & care

• Acclimate: 30–45 min drip; dim lights.

• Handling: Avoid nets; use a container. Spines can snag and envenomate.

• Health: Robust; provide varied greens to prevent HLLE-type erosion.

Venom note

• Dorsal spines deliver painful stings. If stung, immerse the area in tolerably hot water for 30–90 minutes and seek medical advice as needed.

Selection checklist

• Bright color, clear eyes, steady breathing.

• Actively grazes and accepts nori/pellets at the store.

• No frayed fins or pinched belly.