Phyllodiscus semoni
Kwietniewski, 1897
Phyllodiscus
semoni does not look like much during the day. However,
it is a rather bizarre sea anemone that packs an extremely powerful and potentially
dangerous sting. Dangerous
Marine Animals by Bergbauer, Myers & Kirschner calls the "sting
severe, followed by inflammation and long-term discoloration" and they
note it has been reported to have caused a human death in the Philippines. A
paper by Mizuno et al (2007) studying the venom of this anemone states that
it targets the kidney and can cause severe renal injury. Yikes! Don't bump into
them. Unfortunately, they are not easy to recognize. Retracted
into a fuzzy mass of irregular tentacles, it looks like some sort of variably
colored clump of algae. At
night, alien-like, a disk of more typical anemone tentacles erupts from the
top of the clump, and the stalk stretches upward with the cluster of tentacles
at the top. It is no wonder Dangerous Marine Animals calls
it the "Jack-in-the-box anemone." The anemones come in various colors,
as seen in the photo links below. We have not seen, or perhaps should say, not
recognized many specimens. We have perhaps eight recorded, but because of their
cryptic appearance, they are probably a lot more common than this low number
would indicate. Most were out on the oceanside reef, but at least two have been
seen in the lagoon, one on the reef north of Bigej and another on the slope
of the pinnacle at Victor buoy. Several of these we were able to see multiple
times by returning to the same spots over a period of a year or so, but all
eventually vanished, as though they do not live a very long time.
Each thumbnail links
to a larger photo.
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References:
Bergbauer, Matthias; Robert F.
Myers & Manuela Kirschner. 2009. Dangerous Marine Animals.
A&C Black Publishers Ltd. London. 384pp.
Mizuno, Masashi; Masatoshi Nozaki;
Nobuya Morine; Norihiko Suzuki; Kazuhiro Nishikawa; B. Paul Morgan; & Seiichi
Matsuo. 2007. A protein toxin from the sea anemone Phyllodiscus semoni
targets the kidney and causes a severe renal injury with predominant glomerular
endothelial damage. The American Journal of Pathology 171(2):402-414.