Anaerobiosis in the hydrothermal vent tube-worm Riftia pachyptila
In: Cahiers de Biologie Marine. Station Biologique de Roscoff: Paris. ISSN 0007-9723; e-ISSN 2262-3094, meer
Ook verschenen in:(1998). Proceedings of the First International Symposium on Deep-Sea Hydrothermal Vent Biology: Funchal, Madeira, Portugal 20-24 October 1997. Cahiers de Biologie Marine, 39(3-4). Station Biologique de Roscoff: Roscoff. 219-392 pp., meer
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| Auteurs | | Top |
- Arndt, C.
- Schiedek, D., meer
- Felbeck, H.
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| Abstract |
The giant tubeworm Riftia pachyptila Jones, 1981, grows at hydrothermal vents in the mixing zone of the sulphide-laden anoxic vent effluent and oxygenated ambient seawater. Depending on the vent water flow and the degree of mixing, this environment is extremely unstable and can change quickly. Johnson et al. (1988) showed that R. pachyptila and other vent species may experience high sulphide concentrations as well as extreme hypoxia over both short and long periods of time. The sessile tubeworm cannot escape from the frequently hypoxic conditions since it harbours chemoautotrophic, sulphide-oxidizing bacteria in its trophosome cells that require access to the sulphidic vent source as well as to an oxidant. While the symbiotic bacteria could, alternatively, use nitrate or oxygen to oxidize sulphide (Hentschel & Felbeck, 1993), the heterotrophic host R. pachyptila has no nitrate reductase and requires oxygen to maintain its normal aerobic metabolism. We investigated in our study the metabolic capabilities of R. pachyptila to tolerate periods of extreme hypoxia as they frequently occur in its habitat. To characterize the anaerobic metabolic changes of the tubeworm, specimens of R. pachyptila were exposed to experimental hypoxia for different periods of time. |
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