Growth Patterns of Giant Deep Sea Beggiatoaceae from a Guaymas Basin Vent Site

Author(s):  
Dirk de Beer ◽  
Timothy Ferdelman ◽  
Barbara J. MacGregor ◽  
Andreas Teske ◽  
Charles A. Schutte
2004 ◽  
Vol 70 (2) ◽  
pp. 1231-1233 ◽  
Author(s):  
Jens Kallmeyer ◽  
Antje Boetius

ABSTRACT Rates of sulfate reduction (SR) and anaerobic oxidation of methane (AOM) in hydrothermal deep-sea sediments from Guaymas Basin were measured at temperatures of 5 to 200°C and pressures of 1 × 105, 2.2 × 107, and 4.5 × 107 Pa. A maximum SR of several micromoles per cubic centimeter per day was found at between 60 and 95°C and 2.2 × 107 and 4.5 × 107 Pa. Maximal AOM was observed at 35 to 90°C but generally accounted for less than 5% of SR.


2011 ◽  
Vol 30 (1) ◽  
pp. 163-171 ◽  
Author(s):  
Léo Laporte

John Imbrie (b. 1925) always had deep mathematical insight and facility. At Yale University he completed his PhD (1951) under Carl Dunbar working on Middle Devonian brachiopods where he employed a statistical technique—'reduced major axis regression'—to differentiate several subspecies. Later, in a study with Edwin Colbert at the American Museum of Natural History, he used the same technique to determine subtle, yet significant, variations in the growth patterns of Triassic Metoposaurid amphibians (1956). At about the same time as sedimentary facies analysis was becoming of increased interest, Imbrie sought to test what one might do with quantitative facies analysis by undertaking a decade-long study of the Lower Permian Florena Shale (Kansas) using multivariate cluster analysis to characterize different litho- and biofacies. Despite much hard work in the field and with a highdecibel desk calculator, the hoped for results were lackluster. But neither the man nor the methods were wanting. The materials—fragmented, scattered invertebrate fossils imbedded in shales and limestones—permitted no more understanding than qualitative, eye-ball analysis. Even a late stage attack with the IBM computer at Columbia University merely groaned and brought forth similar mousey results. What was needed was a problem whose material components (abundant planktonic microfossils) within well-characterized stratigraphic sequences (deep-sea Pleistocene cores) were suitably matched to the man's mind and his quantitative procedures. And, of course, the result was phenomenal: his empirical demonstration of the deep-sea data for the validity of Milankovitch Cycles as the forcing factors for large-scale global climate change. His scientific success was duly honored by awards, prizes, medals, and elections to distinguished honorary societies. How did this happen?


2015 ◽  
Vol 12 (18) ◽  
pp. 5455-5479 ◽  
Author(s):  
M. Portail ◽  
K. Olu ◽  
E. Escobar-Briones ◽  
J. C. Caprais ◽  
L. Menot ◽  
...  

Abstract. Understanding the ecological processes and connectivity of chemosynthetic deep-sea ecosystems requires comparative studies. In the Guaymas Basin (Gulf of California, Mexico), the presence of seeps and vents in the absence of a biogeographic barrier, and comparable sedimentary settings and depths offers a unique opportunity to assess the role of ecosystem-specific environmental conditions on macrofaunal communities. Six seep and four vent assemblages were studied, three of which were characterised by common major foundation taxa: vesicomyid bivalves, siboglinid tubeworms and microbial mats. Macrofaunal community structure at the family level showed that density, diversity and composition patterns were primarily shaped by seep- and vent-common abiotic factors including methane and hydrogen sulfide concentrations, whereas vent environmental specificities (higher temperature, higher metal concentrations and lower pH) were not significant. The type of substratum and the heterogeneity provided by foundation species were identified as additional structuring factors and their roles were found to vary according to fluid regimes. At the family level, seep and vent similarity reached at least 58 %. All vent families were found at seeps and each seep-specific family displayed low relative abundances (< 5 %). Moreover, 85 % of the identified species among dominant families were shared between seep and vent ecosystems. This study provides further support to the hypothesis of continuity among deep-sea seep and vent ecosystems.


1995 ◽  
Vol 31 (3) ◽  
pp. 186-192 ◽  
Author(s):  
Elisabeth Antoine ◽  
J. Guezennec ◽  
J. R. Meunier ◽  
F. Lesongeur ◽  
G. Barbier

ZooKeys ◽  
2018 ◽  
Vol 764 ◽  
pp. 1-25
Author(s):  
Samuel Gómez

To date, three species of the family Ancorabolidae, three species of the family Argestidae, and one species of the family Rhizothrichidae are known from the deep sea of the Gulf of California. The descriptions of two new species,Eurycletodesparaephippigersp. n.andOdiliacletodessecundussp. n.collected from the Southern Trough of Guaymas Basin at 1440 m and 1642 m depths, respectively, are presented herein. The closest relatives of these two species,E.ephippigerPor, 1964 andO.gracilisSoyer, 1964 are known from the Mediterranean, but some relatives have been reported also from the southern Atlantic.Eurycletodesparaephippigersp. n.is undoubtedly related toE.ephippigerPor, 1964 known from Israel and Banyuls-sur-Mer (France). These two species can be separated by the armature complement of the basis of the maxillule, by the armature complement of the syncoxa of the maxilliped, and by the relative position of the anal operculum.Odiliacletodessecundussp. n.showed to be closely related toO.gracilisSoyer, 1964 known from Banyuls-sur-Mer only. The latter two species can be separated by the armature complement of the syncoxa of the maxilliped, by the structure of the antenna, and by the inner armature complement of the third exopodal segment of the fourth swimming leg.


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