TY - JOUR T1 - A paradox resolved: Sulfide acquisition by roots of seep tubeworms sustains net chemoautotrophy. JF - Proceedings of the National Academy of Sciences of the United States of America Y1 - 2001 A1 - Freytag, J. K. A1 - Girguis, P. R. A1 - Bergquist, D. C. A1 - Andras, J. P. A1 - Childress, J. J. A1 - Fisher, C. R. KW - biology KW - calyptogena-magnifica KW - communities KW - gulf KW - hydrothermal vent KW - mexico KW - organisms KW - symbioses KW - transport KW - worm riftia-pachyptila AB -

Vestimentiferan tubeworms, symbiotic with sulfur-oxidizing chemoautotrophic bacteria, dominate many cold-seep sites in the Gulf of Mexico. The most abundant vestimentiferan species at these sites, Lamellibrachia cf. luymesi, grows quite slowly to lengths exceeding 2 meters and lives in excess of 170-250 years. L. cf. luymesi can grow a posterior extension of its tube and tissue, termed a "root," down into sulfidic sediments below its point of original attachment. This extension can be longer than the anterior portion of the animal. Here we show, using methods optimized for detection of hydrogen sulfide down to 0.1 muM in seawater, that hydrogen sulfide was never detected around the plumes of large cold-seep vestimentiferans and rarely detectable only around the bases of mature aggregations. Respiration experiments, which exposed the root portions of L. cf. luymesi to sulfide concentrations between 51-561 muM, demonstrate that L. cf. luymesi use their roots as a respiratory surface to acquire sulfide at an average rate of 4.1 mu mol.g(-1).h(-1). Net dissolved inorganic carbon uptake across the plume of the tubeworms was shown to occur in response to exposure of the posterior (root) portion of the worms to sulfide, demonstrating that sulfide acquisition by roots of the seep vestimentiferan L. cf. luymesi can be sufficient to fuel net autotrophic total dissolved inorganic carbon uptake.

VL - 98 SN - 0027-8424 IS - 23 N1 -

490WMTimes Cited:82Cited References Count:37

JO - P Natl Acad Sci USAP Natl Acad Sci USA ER -