Riftia pachyptila Jones: Observations on the Vestimentiferan Worm from the Galápagos Rift

The obturacular plume, composed of numerous tentacles, is suggested as a site for the uptake of molecular "food" by Riftia pachyptila (Pogonophora) from the Galápagos Rift; symbiotic bacteria are another possible source of nutrition. Differing organizations of the linings of the five major body cavities of Riftia demonstrate the inadequacy of "coelom" as a descriptive term.