The influence of different incubation media on the carbon transfer from the bacterial symbionts to the hydrothermal vent tube-worm Riftia pachyptila
Felbeck, H.; Jarchow, J. (1998). The influence of different incubation media on the carbon transfer from the bacterial symbionts to the hydrothermal vent tube-worm Riftia pachyptila. Cah. Biol. Mar. 39(3-4): 279-282. https://dx.doi.org/10.21411/CBM.A.8D216C56 In: Cahiers de Biologie Marine. Station Biologique de Roscoff: Paris. ISSN 0007-9723; e-ISSN 2262-3094, more Also appears 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., more |   |
| Abstract | A large fraction of the carbon fixation in the hydrothermal vent community is achieved by symbiotic bacteria (see Childress & Fisher, 1992 for review). In Riftia pachyptila Jones, 1981, these bacteria are found intracellularly in a specialized tissue, the trophosome. The trophosome of the tubeworms comprises between 15 and 30% of the animal's fresh weight and fills most of the body cavity of the animal. It is composed of many lobules which are about 0.15 mm in diameter and are vascularized by the closed circulatory system of the worms. The lobules consist of an outer single layer of cells without bacteria and the central bacteriocyte cells containing the bacterial symbionts. The trophosome is heavily capillarized by small vessels (2-3 mu m diameter). The outside is surrounded by a haemoglobin containing fluid filling the coelomic cavity of the worms. Since the animal has no digestive tract, its nutritional needs have to be filled by other means than eating particulate organic food. Uptake of dissolved amino acids from the surrounding sea water could be demonstrated but their concentration appears to be too low to support the nutritional needs of these large animals. Possibly they can serve as additional nitrogen source. The animal's carbon isotope ratio suggests that the host's organic carbon originates from the bacteria. |
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