This strange looking clump is sometimes called "stinging algae" and ranks high on the list of venomous animals at Kwaj. Stephanoscyphus sp. is quite surprisingly, the polyp stage of thimble jellyfish, and if touched causes "intense pain and wounds which ulcerate and can last for weeks"! Fortunately, it doesn't seem to be common at Kwaj. This colony was discovered several years ago and a special effort was made to relocate and photograph it. See the next photo for a close-up.
10 September 2012