I can’t imagine anyone seeing this strange looking creature for the first time without thinking, “what the heck is that?” With its bizzare looking red-beaconed, gas-filled float on top of a “head” made up of a colony of genetically identical zooids called nectophores and another collection of buoyant zooids that trails behind, it is indeed a standout in the world of cnidarians. Its so-called “tail” works to collects food by stinging and wrapping its prey while doubling as a reproductive and secondary propulsion system. Watching it move is almost as fascinating as it is frustrating (especially for an underwater photographer). It will appear to be relaxing at the surface of the water one moment and then completely fold up and jet off up or down or around the water column. Its method of propulsion is, in fact, being closely studied by a groups of researchers in Washington State in hopes of understanding how its efficient colonial structure might influence the design of underwater propulsion vehicles. For wonderful illustrations of their anatomy and a thorough explanation of their method of propulsion, check out this article in Nature Communications. For more illustrations of their various stages of development see this pdf, written by C.E. Mills et al on Cnidarians (pg 35 of the pdf).**
**(This is an electronic version of the entire Chapter 10, Cnidaria, published in Light and Smith’s Manual: Intertidal Invertebrates of the Central California Coast. Fourth Edition (J.T. Carlton, editor), Berkeley: University of California Press, 2007. To purchase a copy of this book or for permission to reproduce or reprint this material, visit www.ucpress.edu.)**