|Nitrogenous metabolites in tissues and circulating fluids of Riftia pachyptila|
De Cian, M.-C.; Regnault, M.; Lallier, F. (1997). Nitrogenous metabolites in tissues and circulating fluids of Riftia pachyptila, in: Biologie des sources hydrothermales profondes = Biology of deep-sea hydrothermal vents: Journées d'échanges du Programme DORSALES = DORSALES Workshop Roscoff 6-8 octobre 1997. Cahiers de Biologie Marine, 38(2): pp. 122
In: (1997). Biologie des sources hydrothermales profondes = Biology of deep-sea hydrothermal vents: Journées d'échanges du Programme DORSALES = DORSALES Workshop Roscoff 6-8 octobre 1997. Cahiers de Biologie Marine, 38(2)[s.n.][s.l.]. 111-149 pp., more
In: Cahiers de Biologie Marine. Station Biologique de Roscoff: Paris. ISSN 0007-9723, more
|Authors|| || Top |
- De Cian, M.-C.
- Regnault, M.
- Lallier, F.
Distribution of some nitrogen metabolism end-products was investigated in the tissues (trophosome, gill and body wall) and the circulating fluids (blood, coelomic fluid) of the hydrothermal vent tubeworm Riftia pachyptila. Ammonia, urate and nitrite, expected to be the nitrogenous end-products of both Riftia and its symbionts were measured in deep-frozen blood samples and whole animals. The mean concentrations obtained in micromol per liter were all converted to microg N g super(-1) tissue wet weight, or microg N ml super(-1). Ammonia was present in all studied body compartments and appeared to be the prevailing nitrogenous end-product: from 25 to 65 microg N- NH sub(4) super(+) g super(-1) tissue in gill or body wall and trophosome respectively and, around 2 - 4 microg NH sub(4) super(+) g super(-1) in circulating fluids. Urate level was high in the trophosome (17.2 microg N-urate g super(-1)) and occasionally present in the body wall (0 - 4.9 pg N-urate g super(-1)). It was detected neither in the gill nor in circulating fluids. Nitrites were present in the studied body compartments and were largely prevailing in trophosome (1.06 microg N-NO2 super(-) g super(-1)). In contrast to ammonia and urate, nitrite appeared to be negatively affected by the deep freezing/thawing process, as shown by changes in NO2 super(-) content of crab haemolymph submitted to the same treatment as the Riftia blood samples. Therefore, the low nitrite content of blood (9.8 +-2.0 microM, n = 8) could be a result of this unavoidable process. Nitrite measurement on freshly collected animals appears to be necessary. Whether the measured ammonia is the end-product of the tubeworm or that of the endosymbiont is discussed.