Influence of CH4 and H2S availability on symbiont distribution, carbon assimilation and transfer in the dual symbiotic vent mussel Bathymodiolus azoricus
| Autor: | R. S. Santos, F. Dehairs, R. Bettencourt, M. Elskens, S. Bouillon, S. Duperron, S. Halary, V. Riou, A. Colaço |
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| Jazyk: | angličtina |
| Rok vydání: | 2008 |
| Předmět: | |
| Zdroj: | Biogeosciences, Vol 5, Iss 6, Pp 1681-1691 (2008) |
| Druh dokumentu: | article |
| ISSN: | 1726-4170 1726-4189 |
| Popis: | High densities of mussels of the genus Bathymodiolus are present at hydrothermal vents of the Mid-Atlantic Ridge. It was previously proposed that the chemistry at vent sites would affect their sulphide- and methane-oxidizing endosymbionts' abundance. In this study, we confirmed the latter assumption using fluorescence in situ hybridization on Bathymodiolus azoricus specimens maintained in a controlled laboratory environment at atmospheric pressure with one, both or none of the chemical substrates. A high level of symbiosis plasticity was observed, methane-oxidizers occupying between 4 and 39% of total bacterial area and both symbionts developing according to the presence or absence of their substrates. Using H13CO3− in the presence of sulphide, or 13CH4, we monitored carbon assimilation by the endosymbionts and its translocation to symbiont-free mussel tissues. Carbon was incorporated from methane and sulphide-oxidized inorganic carbon at rates 3 to 10 times slower in the host muscle tissue than in the symbiont-containing gill tissue. Both symbionts thus contribute actively to B. azoricus nutrition and adapt to the availability of their substrates. Further experiments with varying substrate concentrations using the same set-up should provide useful tools to study and even model the effects of changes in hydrothermal fluids on B. azoricus' chemosynthetic nutrition. |
| Databáze: | Directory of Open Access Journals |
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