Likely Reef Tank Suitable
Likely Fish-Only Tank Suitable
Rabbitfish belong in the Order Perciformes and Suborder Acanthuroidei as members of the Family Siganidae, which consists of 1 genus with about 27 described species. I should note that previously there was one genus with two subgenera, Lo and Siganus. However, there is insufficient evidence to continue to support the subgenus Lo in the opinion of some notable marine scientists. Those previously placed in the Lo subgenus are now considered to be in the Siganus genus.
These are laterally compressed fish and have small mouths similar to Surgeonfish, which they are actually related to. Their body sides produce little body slime; therefore they have a 'dry' feel when touched. And even though they produce little body slime, they are quite disease resistant and seem to withstand various skin parasites such as Cryptocaryon or Amyloodinium. And even though related to Surgeonfish, they do not have a similar tail spine, however all do have other venomous spines. A sting from these spines can result in a very painful experience. If stung, the wound should be immersed in hot water, which will greatly reduce the level of pain. Always be very careful when working with members of this fish family.
Rabbitfish are mostly found in the Indo-Pacific Ocean, yet a couple of species have migrated from the Red Sea through the Suez Canal to the Mediterranean Sea. Most live on the reef, with some preferring seagrass beds and mangrove areas. In fact, those preferring reef locations have a more colorful appearance. Many of those found in mangrove and estuary areas have a more drab coloration.
In the wild they feed upon various forms/species of algae (macro and micro) including coralline, along with sponges, worms, sessile colonial tunicates and other small invertebrate. Even though technically considered an omnivore, they are excellent herbivores and require a large amount of vegetable matter in their diet. In fact, they are one of the better hair alga consumers and that's a real plus in many of today's aquariums. And even though their closed system diet should mostly consist of vegetable matter, especially some Spirulina flake and nori (dried seaweed/kelp), some meaty foodstuffs should also be made available. And if the aquarium is somewhat devoid of green growths, these fish should receive at least several feedings per day as they are grazing type animals.
Another plus is they are quite disease resistant and very tolerant of poor water quality conditions. It should also be noted that every once and while rabbitfish will shed their outer skin, similar to what some leather corals do occasionally. And even though they are safe with most corals, have found some to have a desire to pick on Xenia.
Keep in mind that adult members of this family are aggressive to each other; therefore only one per aquarium should be tried unless it's a mated pair or a 'very' large aquarium. Unfortunately, the difference between male and female is not clear cut, as the female of each species tends to only be slightly larger than the male, making a positive identification nearly impossible. Yet, if two appear to be getting along with each other in a mixed fish environment, than there's the possibility they may be a pair. Yet if two are purchased and moved to a small system, it might prove to be a mistake. Either way, more than one in the same aquarium is a gamble. And if they do pick on each other, they will become stressed, which will lead to opening the window for a possible disease to become started. And if so, other fish in the aquarium may also be affected.