Embryology of vestimentiferan tube worms from deep-sea methane/sulphide seeps

THE Vestimentifera are gutless worms that live around deep-sea hydrothermal vents and cold seeps, obtaining energy from hydrogen sulphide with the aid of endosymbiotic chemosynthetic bacteria1–3. Their phylogenetic relationships have been debated ever since they were first discovered4,5. Moreover, hydrothermal vents are ephemeral and spatially patchy, raising questions about how vestimentiferan populations are established and maintained6–9, and how symbionts are transmitted10. Although post-settling juveniles have been described11,12, embryos and larvae have been neither collected nor cultured. Here we describe the early development of vestimentiferans from cold seeps in the Gulf of Mexico13, and discuss the implications of our findings for dispersal potential and phylogeny