Vampire Worms; A revision of Galapagomystides (Phyllodocidae, Annelida), with the description of three new species.

Galapagomystides is an exclusively deep-sea group of Phyllodocidae, originally erected for Galapagomystides aristata from hydrothermal vents of the Galapagos Rift. In this study, Phyllodocidae collected from hydrothermal vents and methane seeps from the Pacific Ocean, including specimens from vents of the East Pacific Rise identified as Galapagomystides were studied using morphology (light microscopy and scanning electron microscopy) and DNA sequence data. Phylogenetic analysis of the newly generated molecular data (cytochrome c oxidase subunit I, 16S rRNA, 18S rRNA, and 28S rRNA) combined with an already available extensive dataset for Phyllodocidae resulted in a monophyletic Galapagomystides comprising five species. Galapagomystides aristata was found to occur on the East Pacific Rise vents as well as the Galapagos Rift and is redescribed. Two new species were from hydrothermal vents in the West Pacific, G. bobpearsoni n. sp., and G. kathyae n. sp., as well as one new species from a cold seep in the eastern Pacific, G. patricki n. sp. These new species are formally described, and a previously known vent species, Protomystides verenae, is redescribed and transferred to Galapagomystides. Galapagomystides verenae n. comb. was found to occur in both vents and seeps in the eastern Pacific, from Oregon to Costa Rica. The diagnosis of Galapagomystides is amended and the biogeography and habitat evolution of the five species of Galapagomystides is discussed.