“Sarcophyton” ehrenbergi, the False Toadstool Coral. Credit: Dr. Yehuda Benayahu
Zoological taxonomy is not for the feint of heart. Take, for instance, the humble Toadstool Coral— a stalwart soft coral recommended to every rookie reef aquarist. Despite the ubiquity and importance of these corals in reef ecosystems, our understanding of their evolutionary relationships is in a nascent stage. There are no field guides enabling easy identification, and, in all likelihood, there never will be. Recent molecular study has shown that our current system for classifying the Toadstool Corals and their allies is inherently wrong in many different and important ways. If you’ve ever purchased one of these at an aquarium store, you’ve likely noticed that there is usually no attempt at a species-level identification, nor do we see the kind of fanciful common names so abundant elsewhere in this hobby. No Strawberry Shortcake Toadstool. No Superman Toadstool. No Green Death Toadstool. The Fiji Yellow Toadstool is the only exception. This is in spite of the fact that many distinctive phenotypes regularly show up. If Eskimos have fifty words for snow, why is there but one word for this diverse group of corals? Alas, our naming troubles are to be found amongst the scientific community as well. There are perhaps a handful of people on the planet right now with any real expertise in these corals (note: I am not one of these people), and the general consensus is that we don’t really understand the boundaries between species. One recent molecular study found that what had previously been considered a single variable taxon was in fact comprised of no less than six distinct and distantly related lineages. Ex uno, plures.The situation is equally unclear when considering the genus-level classification. As any coral nerd worth their salt can tell you, Toadstool Corals are in Sarcophyton, the similar Devil’s Hand Corals are in Lobophytum, and never the twain shall meet. But it turns out, the twain do meet. Instead of two discrete morphologies, there is really more of a continuum of shapes blending these two extremes. Sarcophyton, in its purest form, does indeed look much like a toadstool and can be recognized in possessing a stalk upon which sits a smooth cap (=polypary or capitulum). Lobophytum, on the other hand (pun), have a heterogenous look which is perhaps best described as untoadstool-like, with some species being tall and fingerlike and others being flat and ridged.… More:
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