@article {Thiel2012,
	title = {{Widespread occurrence of two carbon fixation pathways in tubeworm endosymbionts: lessons from hydrothermal vent associated tubeworms from the Mediterranean Sea}},
	journal = {Frontiers in Microbiology},
	volume = {2},
	year = {2012},
	pages = {423},
	abstract = {Vestimentiferan tubeworms (siboglinid polychetes) of the genus Lamellibrachia are common members of cold seep faunal communities and have also been found at sedimented hydrothermal vent sites in the Pacific. As they lack a digestive system, they are nourished by chemoautotrophic bacterial endosymbionts growing in a specialized tissue called the trophosome. Here we present the results of investigations of tubeworms and endosymbionts from a shallow hydrothermal vent field in the Western Mediterranean Sea. The tubeworms, which are the first reported vent-associated tubeworms outside the Pacific, are identified as Lamellibrachia anaximandri using mitochondrial ribosomal and cytochrome oxidase I (COI) gene sequences. They harbor a single gammaproteobacterial endosymbiont. Carbon isotopic data, as well as the analysis of genes involved in carbon and sulfur metabolism indicate a sulfide-oxidizing chemoautotrophic endosymbiont. The detection of a hydrogenase gene fragment suggests the potential for hydrogen oxidation as alternative energy source. Surprisingly, the endosymbiont harbors genes for two different carbon fixation pathways, the Calvin-Benson-Bassham (CBB) cycle as well as the reductive tricarboxylic acid (rTCA) cycle, as has been reported for the endosymbiont of the vent tubeworm Riftia pachyptila. In addition to RubisCO genes we detected ATP citrate lyase (ACL {\textendash} the key enzyme of the rTCA cycle) type II gene sequences using newly designed primer sets. Comparative investigations with additional tubeworm species (Lamellibrachia luymesi, Lamellibrachia sp. 1, Lamellibrachia sp. 2, Escarpia laminata, Seepiophila jonesi) from multiple cold seep sites in the Gulf of Mexico revealed the presence of acl genes in these species as well. Thus, our study suggests that the presence of two different carbon fixation pathways, the CBB cycle and the rTCA cycle, is not restricted to the Riftia endosymbiont, but rather might be common in vestimentiferan tubeworm endosymbionts, regardless of the habitat.},
	keywords = {ROV Jason (Remotely Operated Vehicle)},
	doi = {10.3389/fmicb.2012.00423},
	author = {Thiel, Vera and Hugler, M and Bl{\"u}mel, M and Baumann, H I and G{\"a}rtner, A and Schmaljohann, R and Strauss, H and Garbe-Schonberg, D and Petersen, S and Cowart, D A and Fisher, C R and Imhoff, J F}
}
@article {Miglietta2010,
	title = {{Species boundaries of Gulf of Mexico vestimentiferans (Polychaeta, Siboglinidae) inferred from mitochondrial genes}},
	journal = {Deep-Sea Research. Part II: Topical Studies in Oceanography},
	volume = {57},
	number = {21-23},
	year = {2010},
	pages = {1916{\textendash}1925},
	abstract = {At least six morphospecies of vestimentiferan tubeworms are associated with cold seeps in the Gulf of Mexico (GOM). The physiology and ecology of the two best-studied species from depths above 1000 m in the upper Louisiana slope (Lamellibrachia luymesi and Seepiophila jonesi) are relatively well understood. The biology of one rare species from the upper slope (escarpiid sp. nov.) and three morphospecies found at greater depths in the GOM (Lamellibrachia sp. 1, L. sp. 2, and Escarpia laminata) are not as well understood. Here we address species distributions and boundaries of cold-seep tubeworms using phylogenetic hypotheses based on two mitochondrial genes. Fragments of the mitochondrial large ribosomal subunit rDNA (16S) and cytochrome oxidase subunit I (COI) genes were sequenced for 167 vestimentiferans collected from the GOM and analyzed in the context of other seep vestimentiferans for which sequence data were available. The analysis supported five monophyletic clades of vestimentiferans in the GOM. Intra-clade variation in both genes was very low, and there was no apparent correlation between the within-clade diversity and collection depth or location. Two of the morphospecies of Lamellibrachia from different depths in the GOM could not be distinguished by either mitochondrial gene. Similarly, E. laminata could not be distinguished from other described species of Escarpia from either the west coast of Africa or the eastern Pacific using COI. We suggest that the mitochondrial COI and 16S genes have little utility as barcoding markers for seep vestimentiferan tubeworms.},
	keywords = {HOV Alvin (Human Occupied Vehicle), ROV Jason (Remotely Operated Vehicle)},
	issn = {0967-0645},
	doi = {10.1016/j.dsr2.2010.05.007},
	url = {http://dx.doi.org/10.1016/j.dsr2.2010.05.007},
	author = {Miglietta, M P and Hourdez, S and Cowart, D A and Schaeffer, S W and Fisher, C R}
}
