Can I Get One of Those Rabbits
Commonly Available Rabbitfish for Algae-Grazing
|The Virgate Rabbitfish, sometimes called the Double Barred Rabbitfish, is an excellent grazer
In this issue of Blue Zoo News, we have shed some light on the utility and appropriateness of certain species of rabbitfishes for marine aquarists interested in a herbivorous fishes for biological control of algae. The star of this story, as the article "Sleeper Cells and Unusual Suspects" (this issue of Blue Zoo News) makes abundantly clear, is a rabbitfish called the White Spotted Rabbitfish (Siganus canaliculatus), which may lead some aquarists to inquire as to where they can get one. While the White Spotted Rabbitfish is rarely if ever seen in the aquarium trade in North America, there are others that should be considered for both their utility and their beauty.
"We often use rabbitfishes as our herbivores of choice to keep our coral and fish rearing tanks clean at the James Cook University experimental aquarium facility," says David Bellwood, whose research is discussed in Part II of our series on herbivorous fishes. For anyone who has read the article, this should not come as a surprise. For those of you that have not read the article yet, certain species of rabbitfishes have been shown by Bellwood and his research team to be some of the best reef herbivores.
Often reef aquarists steer clear of rabbitfishes—rightfully Siganids from the Family Siganidae—because they are not reef-compatible. Bellwood says that, in his experience, "Siganids are excellent with corals—with minimal disturbance." While we at Blue Zoo still only recommend them as reef compatible with caution, we hope more aquarists will employ rabbitfishes for biological control of algae (even in reef tanks) based on the compelling scientific data presented by Bellwood's team.
While the article touts the algae-eating ability of the white spotted rabbitfish (S. canaliculatus), Bellwood points out that this species is not generally considered an attractive fish, and this has probably limited its use in the hobby where function is important, but aesthetics are often king.
In addition, Bellwood notes that white spotted rabbitfish are common in places but generally very hard to find. "We are hunting them actively with limited success," he says. "They are more common in temperate areas and in mangroves and are collected in huge numbers in the Philippines for food." Bellwood points out that the species boundaries between the white spotted rabbitfish and S. fuscescens and S. margaritiferus are unclear, but, nonetheless, "[the white spotted rabbitfish] have been so heavily overharvested that they are in decline in many areas." This is of course concerning given the results of Bellwood's research and the importance of this fish species as a reef grazers, but the aquarium industry is surely not to blame. "I do not think anyone would buy a canaliculatus,” Bellwood says, “except to eat it."
So if the best algae-grazer is “ungettable” by most North American aquarists, what’s the next best thing? Bellwood says, Scribbled Rabbitfish (S. doliatus) are common on reefs in Australia. Likewise, he says, "S. virgatus [commonly called the Virgate Rabbitfish] in the Philippines is a similar beast and quite common." Both of these fishes are rightfully quite popular with aquarists considering a rabbitfish, and they are readily available in the trade. Based on their looks, durability and functional utility, we here at BZA recommend them whole-heartedly.
Published 10 June 2008. © Blue Zoo Aquatics