title: Sunken wood habitat for thiotrophic symbiosis in mangrove swamps.
abstract: Large organic falls to the benthic environment, such as dead wood or whale bones, harbour organisms relying on sulfide-oxidizing symbionts. Nothing is known however, concerning sulfide enrichment at the wood surface and its relation to wood colonization by sulfide-oxidizing symbiotic organisms. In this study we combined in situ hydrogen sulfide and pH measurements on sunken wood, with associated fauna microscopy analyses in a tropical mangrove swamp. This shallow environment is known to harbour thiotrophic symbioses and is also abundantly supplied with sunken wood. A significant sulfide enrichment at the wood surface was revealed. A 72h sequence of measurements emphasized the wide fluctuation of sulfide levels (0.1->100muM) over time with both a tidal influence and rapid fluctuations. Protozoans observed on the wood surface were similar to Zoothamnium niveum and to vorticellids. Our SEM observations revealed their association with ectosymbiotic bacteria, which are likely to be sulfide-oxidizers. These results support the idea that sunken wood surfaces constitute an environment suitable for sulfide-oxidizing symbioses.
authors.affiliation: Université des Antilles et de la Guyane, UFR des Sciences Exactes et Naturelles, Département de Biologie, B.P. 592, 97159 Pointe-à-Pitre Cedex, Guadeloupe, France. melina.laurent@univ-ag.fr
authors.forename: Mélina C Z
authors.initials: MC
authors.lastname: Laurent
authors.forename: Olivier
authors.initials: O
authors.lastname: Gros
authors.forename: Jean-Pierre
authors.initials: JP
authors.lastname: Brulport
authors.forename: Françoise
authors.initials: F
authors.lastname: Gaill
authors.forename: Nadine Le
authors.initials: NL
authors.lastname: Bris
mesh_terms: D000818:Animals; D001419:Bacteria / Q000254:growth & development / Q000378:metabolism; D044822:Biodiversity; D017753:Ecosystem; D006862:Hydrogen Sulfide / Q000032:analysis / Q000378:metabolism; D016802:Oligohymenophorea / Q000382:microbiology; D010084:Oxidation-Reduction; D013440:Sulfides / Q000032:analysis / Q000378:metabolism; D013559:Symbiosis; D014867:Water / Q000737:chemistry; D014872:Water Movements; D053833:Wetlands; D014934:Wood
chemical_list: D013440:Sulfides; D014867:Water; D006862:Hydrogen Sulfide