A scanning elcctron microscope image of Convexella, the deepest known sea fan, from the incredible depth of 5850 meters in the frigid Antarctic Ocean. Octocorals in the family Primnoidae (prim-no-id-day) are some of the most beautiful gorgonians because of their complex polyp architecture. Convexella krampi (Madsen, 1956) holds the depth record, ranging throughout the Antarctic, subantarctic South America, North Atlantic, and Kermdec Trench.
The image above looks down on a whorl of delicately armored polyps of Convexella magelhaenica, a sister species to C. krampi. The whorl of polyps is on the order of 2-3 mm. The illustration is part of a new generic revision of the octocoral family Primnoidae by Smithsonian curators Dr. Steven Cairns and F.M. Bayer (2009).
Cairns, SD & FM Bayer. 2009. A Generic Revision and Phylogenetic Analysis of the Primnoidae. Smithsonian Contributions to Zoology, No. 629. Smithsonian Institution Scholarly Press, Washington, DC.