TY - JOUR
T1 - Stable isotope evidence for a putative endosymbiont-based lithotrophic Bathymodiolus sp. mussel community atop a serpentine seamont
AU - Yamanaka, Toshiro
AU - Mizota, Chitoshi
AU - Satake, Hiroshi
AU - Kouzuma, Fumitaka
AU - Gamo, Toshitaka
AU - Tsunogai, Urumu
AU - Miwa, Tetsuya
AU - Fujioka, Kantaro
N1 - Funding Information:
Sulfur isotopic measurement was done at the Institute for Study on the Earth’s Interior, Okayama University. We are grateful to Minoru Kusakabe for providing the laboratory facility. We wish to thank K. Hirata and the ROV Kaiko operation team, and the captain K. Hasegawa and the crew of R/V Kairei for their invaluable collaboration during the shipboard work. We acknowledge the editorial handling of Kenji Kato, Shizuoka University, William C. Ghiorse, Cornell University, and four anonymous referees who provided valuable comments and constructive suggestions, which greatly improved the early version of the manuscript. This research was partly funded by the Ministry of Education, Culture, Sports, Science, and Technology of Japan through the Special Coordination Fund called the “Archaean Park” project.
PY - 2003/5
Y1 - 2003/5
N2 - A putative endosymbiont-based benthic animal community composed of at least two kinds of bivalves has been found atop the South Chamorro serpentine seamount in the Mariana fore-arc, western Pacific. Multiple stable isotopic analyses (hydrogen, carbon, nitrogen, and sulfur) were carried out on the soft tissues of an undescribed mussel species belonging to the genus Bathymodiolus. Markedly higher stable carbon (δ13C: - 21.4 to - 18.9‰ vs. PDB) and lower sulfur (δ34S: + 10.2 to + 10.6‰ vs. CDT) isotopic compositions of the mussel tissues suggested that they utilized both methane and sulfide as nutrient sources of carbon and sulfur: Analyses of in situ shimmering water and clayey sediment under the mussel bed supported these findings. These results strongly suggest that the mussels harbored both methanotrophic and thioautotrophic bacterial symbionts in their gills. This is the first stable isotopic evidence of a dual symbiotic Bathymodiolus sp. in the western Pacific. It is proposed that the major substrates for energy acquisition-methane and hydrogen sulfide-may be responsible for results from serpentinization in the lower crust. This abiotic process would be followed by abiotic or archaeal methane production and bacterial sulfate-reduction as evidenced by high δ13C value (- 14.6‰) of methane in the shimmering water and low δ34S value (- 32.3‰) of sulfides in the immediate sediments, respectively. Due to the very low organic matter content (0.5 mg C/g dry sediment) of the immediate sediment, it is further proposed that sulfate-reduction occurred using hydrogen (or possibly methane) as an electron donor. Thus, the mussel community living independently of magmatism and sedimentary organic matter is a lithotrophic animal community.
AB - A putative endosymbiont-based benthic animal community composed of at least two kinds of bivalves has been found atop the South Chamorro serpentine seamount in the Mariana fore-arc, western Pacific. Multiple stable isotopic analyses (hydrogen, carbon, nitrogen, and sulfur) were carried out on the soft tissues of an undescribed mussel species belonging to the genus Bathymodiolus. Markedly higher stable carbon (δ13C: - 21.4 to - 18.9‰ vs. PDB) and lower sulfur (δ34S: + 10.2 to + 10.6‰ vs. CDT) isotopic compositions of the mussel tissues suggested that they utilized both methane and sulfide as nutrient sources of carbon and sulfur: Analyses of in situ shimmering water and clayey sediment under the mussel bed supported these findings. These results strongly suggest that the mussels harbored both methanotrophic and thioautotrophic bacterial symbionts in their gills. This is the first stable isotopic evidence of a dual symbiotic Bathymodiolus sp. in the western Pacific. It is proposed that the major substrates for energy acquisition-methane and hydrogen sulfide-may be responsible for results from serpentinization in the lower crust. This abiotic process would be followed by abiotic or archaeal methane production and bacterial sulfate-reduction as evidenced by high δ13C value (- 14.6‰) of methane in the shimmering water and low δ34S value (- 32.3‰) of sulfides in the immediate sediments, respectively. Due to the very low organic matter content (0.5 mg C/g dry sediment) of the immediate sediment, it is further proposed that sulfate-reduction occurred using hydrogen (or possibly methane) as an electron donor. Thus, the mussel community living independently of magmatism and sedimentary organic matter is a lithotrophic animal community.
KW - Deep-sea mussel Bathymodiolus
KW - Dual symbiosis
KW - Energy acquisition
KW - Lithotrophic animal community
KW - Multiple stable isotopes
KW - Serpentine seamount
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U2 - 10.1080/01490450303876
DO - 10.1080/01490450303876
M3 - Article
AN - SCOPUS:0042575642
VL - 20
SP - 185
EP - 197
JO - Geomicrobiology Journal
JF - Geomicrobiology Journal
SN - 0149-0451
IS - 3
ER -