Soon I will be heading to Bonaire for about 7 weeks of work with the marine park there. I'm not sure how many posts I'll get up between now and then, but here's one for the fans.
Sea fans are odd animals. They're Cnidarians and have Cnidocytes (I need to include these guys every few weeks to justify the title). Fans are part of a group of soft-corals referred to as gorgonians. For the non-biologists, they are made up of hundreds or thousands of tiny, eight-tentacled polyps (they're in the group Octocorallia) that secrete the fan. They use their tentacles to capture particles in the water that pass by. They sure make beautiful patterns.