Nausithoe racemosa is one of the jellyfish with generations that alternate between the benthic polypoid form shown here and a thimble jellyfish-like medusa stage. Little is known of its life history. What is known, however, is that this benthic stage possesses powerful stinging nematocysts. Not easily recognized as a polyp, this stuff is sometimes called "stinging algae," although algae it certainly is not. Fortunately, here at Kwaj it is rather scarce and when found is usually in somewhat shaded ledges and overhangs where divers are not likely to accidentally run into it. The small greenish polyps are just a few millimeters in diameter.
A complete colony.
Closer views.
Created 20 October 2015
Updated 14 October 2019