The Hardy, Handsome, Largely Herbivorous Foxface Rabbitfish

Foxface Rabbitfish (Siganus vulpinus) are generally hardy herbivores

Foxface Rabbitfish (Siganus vulpinus) are generally hardy herbivores

When it comes to marine fish that earn their keep from the standpoint of visual interest, general ruggedness, and utility in the aquarium, few species can compete with the foxface rabbitfish (Siganus vulpinus). If provided adequate housing and an appropriate diet, this species is even well suited to beginners’ tanks. What’s more, S. vulpinus gives any tang a run for its money when it comes to cleaning up irksome algae.

Physical characteristics

Hailing from the Western Pacific, S. vulpinus is laterally compressed (flattened from side to side) with an elongated snout that gives the species a somewhat fox-like aspect. It’s a cheery bright yellow over the rear two-thirds of its body (approximately), giving way to a white base coloration on the anterior third. A black band extends upward diagonally from the tip of the snout to just before the first dorsal spine. The chest area is also black. When stressed, this species can rapidly take on a mottled coloration.

Venomous spines

It’s noteworthy that S. vulpinus, in common with all its congeners, possesses sharp, venomous dorsal and anal spines, which are capable of inflicting a nasty, painful sting. The utmost care must be exercised when transferring specimens, working in the tank, etc. These spines are typically used only defensively, so you don’t have to worry about your foxface attacking your hand. Nonetheless, it’s very possible for careless handling or relaxed vigilance to result in a sting.

If a sting should occur, seek medical attention immediately. As far as I’m aware, the most common symptom of a foxface sting is severe pain (I can’t speak from personal experience), but different people can react to venom in very different ways.

Foods fit for a foxface

Though S. vulpinus is omnivorous and will happily accept small, meaty food items, such as mysid shrimp, its captive diet should consist primarily of green matter with occasional meaty offerings. Good options include dried marine algae sheets, commercial frozen herbivore formulations, and spirulina flakes or pellets. Occasionally soaking dried foods in a quality vitamin/HUFA supplement before feeding will help to fill in any nutritional gaps. Of course, many forms of live algae growing in the tank will be eaten with gusto, as well.

Recommended tank size

An aquarium in the range of 75 gallons is commonly recommended for this species. However, I would advise going with something quite a bit larger—more along the lines of 125 gallons—as minimum housing. S. vulpinus can grow to exceed 9 inches in length and needs a decent amount of swimming room to boot. A 75-gallon, while suitable for younger, smaller specimens, just doesn’t provide adequate long-term accommodations for a foxface in my humble opinion.

Tankmates and reef suitability

When it comes to fish tankmates, S. vulpinus doesn’t create much in the way of compatibility issues. Foxfaces are usually indifferent to most other species, and other fish species—even relatively aggressive and predatory ones—tend to leave them alone out of respect for those venomous spines. Conspecifics will squabble, however, so it’s best to keep only one foxface per tank.

With respect to inclusion in reef systems, the best advice is to proceed with caution. S. vulpinus isn’t a significant threat to corals, but, like many grazers are prone to do, it may nibble on fleshy coral polyps.


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About Jeff Kurtz

Jeff Kurtz is the Co-founder/Editor of Saltwater Smarts, former Senior Consulting Editor for Tropical Fish Hobbyist Magazine, and the aquarist formerly known as “The Salt Creep.” He has been an aquarium hobbyist for over 30 years and is an avid scuba diver.


  1. My one spot Fox Face tends to host my Toadstool leather… He’s an odd fish

  2. I have gotten stung on my thumb from mine. I would rather have gotten run over by a Mack Truck, then have the driver put it in reverse and run me over again, then have a retired Supermodel stick me in the eye with a long spined urchin. That’s somewhat what it felt like to be stung by one of those. Fire coral gave me the same response.

  3. i just read that one of these fishes was recently discovered and captured by, off the coast of Florida in the USA; where they are non-native and invasive. i am not familiar with your site, so i don’t know if you already do this; hoping you stress to your followers never to release any fish into the open waters.

    • Hi Donna! Thanks for sharing this info. Here at Saltwater Smarts, we definitely emphasize that our tank denizens should never be released into the wild under any circumstances. Here’s a previous post on that very topic:

      • Thanks Jeff for the link to your article. I was hoping that was the case; as I see that you are also a Scuba Diver 🙂
        I appreciate your efforts to keep our waters healthy.
        Happy New Year

      • Help my naso got stung by accident.this i know cuz there in love for sure.i turned up heat warmth helps anything else i can do?

        • Jeff Kurtz says

          Hi Jared! I’ve often heard the recommendation of using hot (but not scalding) water to treat the site of a foxface sting in people, but I’m not aware that increasing an aquarium’s water temperature will help a fish that’s been stung to any significant degree. At this point, I’d keep a close eye on the victim and be prepared to move it to a treatment tank if if shows any sign of secondary infection at the site of the sting.

          Assuming the victim pulls through, you might also need to consider rehoming one or the other to avoid recurrence.

  4. Garvin Blackmon says

    Any images of Young or Juvanial Foxface??

  5. Marcus hardaway says

    I had a juvenile foxface and recently added a magnificent foxface and another larger one that is mostly black. The two larger ones were added together. All 3 became a group swimming the tank together which is 260 gallon. I have other tanks lots of angel but I recently added a large majestic angel. He stays to himself but afterwards the magnificent foxface became aggressive and started chasing the othe large one. I separated him in my quarantine tank. I do not understand how they were all great together for a month or so and now the one is out for blood. Will I ever be able to add him back? The small one may be 2” the magnificent is about 5” and the mostly black one is nearly 6”. I give them plenty of veggies food and some meaty not sure what to do.

  6. Celica Outen says

    Hello, I recently adopted a Fox face myself and noticed a behavior I cannot find information on at all. When I walk by the tank it almost looks like around his eyes are flashing a dull white. Has anyone ever seen this behavior or have an explanation to it? He doesn’t turn aggressive or fan his spikes, its almost as if he is trying to catch my attention or something lol

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