title: Novel forms of structural integration between microbes and a hydrothermal vent gastropod from the Indian Ocean.
abstract: Here we describe novel forms of structural integration between endo- and episymbiotic microbes and an unusual new species of snail from hydrothermal vents in the Indian Ocean. The snail houses a dense population of gamma-proteobacteria within the cells of its greatly enlarged esophageal gland. This tissue setting differs from that of all other vent mollusks, which harbor sulfur-oxidizing endosymbionts in their gills. The significantly reduced digestive tract, the isotopic signatures of the snail tissues, and the presence of internal bacteria suggest a dependence on chemoautotrophy for nutrition. Most notably, this snail is unique in having a dense coat of mineralized scales covering the sides of its foot, a feature seen in no other living metazoan. The scales are coated with iron sulfides (pyrite and greigite) and heavily colonized by epsilon- and delta-proteobacteria, likely participating in mineralization of the sclerites. This novel metazoan-microbial collaboration illustrates the great potential of organismal adaptation in chemically and physically challenging deep-sea environments.
authors.affiliation: Monterey Bay Aquarium Research Institute, Moss Landing, California 95039, USA. goffredi@mbari.org
authors.forename: Shana K
authors.initials: SK
authors.lastname: Goffredi
authors.forename: Anders
authors.initials: A
authors.lastname: Warén
authors.forename: Victoria J
authors.initials: VJ
authors.lastname: Orphan
authors.forename: Cindy L
authors.initials: CL
authors.lastname: Van Dover
authors.forename: Robert C
authors.initials: RC
authors.lastname: Vrijenhoek
mesh_terms: D000818:Animals; D004947:Esophagus / Q000382:microbiology; D019156:Indian Ocean; D007501:Iron / Q000378:metabolism; D008969:Molecular Sequence Data; D010802:Phylogeny; D020560:Proteobacteria / Q000145:classification / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism; D012336:RNA, Ribosomal, 16S; D012623:Seawater / Q000382:microbiology*; D017422:Sequence Analysis, DNA; D012908:Snails / Q000033:anatomy & histology* / Q000382:microbiology*; D013440:Sulfides / Q000378:metabolism; D013559:Symbiosis
chemical_list: D012336:RNA, Ribosomal, 16S; D013440:Sulfides; C111959:greigite; C011342:pyrite; D007501:Iron