Foxface Lo

The Foxface Lo (Siganus vulpinus) is a striking and highly recognizable saltwater fish prized for its bright yellow body, contrasting white face, and bold dark facial markings. Its elongated, fox-like snout gives this popular rabbitfish its common name, while its active swimming behavior and vivid coloration make it an excellent centerpiece for larger marine aquariums.

Native to the Western Pacific, including Indonesia, the Philippines, New Guinea, the Great Barrier Reef, and surrounding island regions, the Foxface Lo naturally inhabits coral reefs and spends much of the day grazing on algae. In captivity, it is valued not only for its appearance but also for its constant browsing behavior, which can help control many types of nuisance algae.

Generally peaceful toward unrelated tankmates, this species works well in both large fish-only aquariums and carefully managed reef aquariums. It does, however, possess venomous dorsal, anal, and pelvic spines, and occasional individuals may nip at corals if their nutritional needs are not adequately met.

Quick Care Guide

Care Level: Easy
Minimum Tank Size: 125 gallons
Temperament: Peaceful
Diet: Herbivore
Reef Safe: With Caution
Region: Western Pacific
Scientific Name: Siganus vulpinus

Tank Requirements

Provide a spacious aquarium with a combination of open swimming room and substantial live rock for grazing, shelter, and nighttime resting areas. Foxface Lo rabbitfish are active during the day and benefit from a mature aquarium where natural algae can develop on the rockwork.

Caves, overhangs, and secure crevices should be available, as the fish may retreat into the aquascape when frightened or when settling down for the night. Rock structures should be stable and arranged so the fish can move comfortably without becoming trapped.

Good filtration, consistent water quality, and moderate to strong water movement are appropriate. A secure aquarium cover is recommended, particularly during acclimation when the fish may be more easily startled.

Diet and Feeding

The Foxface Lo is primarily herbivorous and should receive a vegetable-rich diet. Marine algae and seaweed sheets such as nori should be offered regularly, preferably attached to a feeding clip so the fish can graze naturally throughout the day.

Supplement its diet with spirulina-based foods, quality herbivore pellets, algae-based frozen preparations, and other marine vegetable blends. Small amounts of mysis shrimp, enriched brine shrimp, and mixed frozen marine foods can provide additional dietary variety.

Feed one to three times daily depending on the amount of natural grazing available in the aquarium. Keeping the fish well fed with appropriate algae-based foods may also reduce the likelihood of coral nipping.

Temperament and Tankmates

The Foxface Lo is generally peaceful toward most unrelated marine fish and can be housed with a wide variety of community species. Suitable tankmates include tangs, angelfish, clownfish, wrasses, gobies, larger anthias, and many other peaceful to moderately assertive marine fish.

It can be shy when first introduced but typically becomes confident once accustomed to its surroundings. When frightened or resting, its normally bright coloration may temporarily darken or become mottled. This color change is normal behavior.

Aggression is most likely toward other rabbitfish, particularly fish with a similar shape or appearance. Keeping multiple Foxface or closely related rabbitfish together should be approached cautiously unless the aquarium is exceptionally large and the fish are a compatible pair.

Its venomous spines are primarily defensive rather than aggressive, but care should always be taken when working around or transferring the fish.

Reef Compatibility

Reef Safe: With Caution.

The Foxface Lo is commonly maintained in reef aquariums and usually ignores corals when adequately fed. However, reef compatibility can vary between individuals.

A hungry specimen may nip at fleshy LPS corals, soft corals, zoanthids, or other coral polyps. Providing abundant marine algae and frequent vegetable-based feeding can help reduce this behavior, but complete coral safety cannot be guaranteed.

It generally poses little threat to ornamental shrimp, crabs, snails, and other mobile invertebrates compared with predatory marine fish.

Water Parameters

Temperature: 75–80°F
Specific Gravity: 1.024–1.026
pH: 8.1–8.4
Alkalinity: 8–12 dKH

Maintain stable water chemistry and avoid rapid changes in temperature, salinity, or pH. Consistency and good overall water quality are more important than attempting to maintain one exact value within these ranges.

Common Considerations

• Possesses venomous dorsal, anal, and pelvic spines; use caution whenever working around or transferring the fish.

• Requires substantial swimming space as it matures and can approach approximately 10 inches in adult length.

• May temporarily develop dark or mottled coloration when sleeping, stressed, or frightened.

• Can become territorial toward other Foxface or closely related rabbitfish.

• Usually works well in reef aquariums but may occasionally nip at coral polyps, particularly when inadequately fed.