While snorkeling north of Pigeon Island, St. Lucia, we encountered a ctenophore (related to jellyfish) floating by. This was, by far, the largest one I’ve ever seen up close, not quite as large as my fist (Anne’s fist, not Chris’, which is considerably larger). Looking online, I determined that it most closely resembles the picture of Ocyropsis maculata, as shown in what appears to be a pdf file of a textbook chapter on ctenophores (Plate 75B at http://faculty.washington.edu/cemills/LSM2007Ctenophora.pdf). If you look close at the picture on the left, you can see the luminescent cilia, kind of like little hairs, along the ctenophore’s top left edge. The cilia run in lines from the top to the bottom of the lobes and beat in waves, propelling the ctenophore through the water. The pink spots inside might be gonad. In the picture on the right, you can see much better the separation of the two lobes. We see lots of ctenophores (usually much smaller) when we snorkel, and also when we’re sailing at night, because when they’re disturbed, they let off a blast of blue light, which looks really fantastic in the dark water.
NOTE: I couldn’t find anywhere the ctenophores are actually eaten by people, though dried jellyfish are a delicacy in some Asian countries. No thanks.