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  • 1
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Publishing Ltd
    The @journal of eukaryotic microbiology 42 (1995), S. 0 
    ISSN: 1550-7408
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: . Epifluorescence microscopy and spectrofluorimetry were investigated as possible non-terminal methods to distinguish live from dead foraminifera. Seven fluorogenic probes (diacetates of fluorescein [FDA], carboxyfluorescein, dichlorofluorescein, and carboxyeosin; AM-esters of biscarboxyethylcarboxyfluorescein [BCECF-AM], calcein, and calcein blue) were tested on Allogromia laticollaris. The probes that consistently produced the brightest fluorescence signals (BCECF-AM and FDA) were judged non-toxic to Allogromia, on the basis of short-term pseudopodial deployment and long-term reproduction assays. Once protocols were established, these two probes were tested on 13 additional benthic foraminiferal species. We found that BCECF-AM is the most suitable probe for direct epifluorescence microscopy of metabolically active foraminifera, especially tectinous and transparent calcareous species. Using spectrofluorimetry, FDA showed promise for opaque species because fluorescence is detected in the incubation media after its release from the cell. However, both approaches could only be used with confidence in light of appropriate controls established for each species examined.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Publishing Ltd
    The @journal of eukaryotic microbiology 40 (1993), S. 0 
    ISSN: 1550-7408
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: . The fine structure, elastic properties, and distribution of the fibrous, meshlike cement (bioadhesive) were studied for the test of the antarctic agglutinated foraminiferan Astrammina rara. Grain-size analysis of particles incorporated into the test compared with adjacent sediment indicates that A. rara is grain-size selective. Fractured tests curl inward, suggesting that the test is under tension—an impression substantiated by micromanipulation observations. Changes in test appearance were examined by scanning electron microscopy after sequential chemical treatments combined with ultrasonication. Organic fibrils securing fine-grained particulates on the test exterior were removed during initial sonication. A veil of fibrous organic material lining the test interior (i.e. inner organic lining) was removed by treatment with a nonionic detergent, revealing ligamentous cables of bioadhesive securely joining large grains. These cables are partially disrupted by treatment with sodium dodecyl sulfate, and further disrupted by disulfide reducing agents, suggesting that protein is an integral adhesive component. The large detrital grains incorporated into the test are arranged in an interlocked, optimally packed fashion. Together, these observations indicate that the seemingly simple spherical architecture of A. rara's test is in fact quite complex, consisting of large grains compressed by tensile cables of a proteinaceous bioadhesive, with additional rigidity supplied by fine particulate “mortar” deposited externally.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Science Inc
    The @journal of eukaryotic microbiology 52 (2005), S. 0 
    ISSN: 1550-7408
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: Eukaryote origin and earliest diversification occurred in the Proterozoic when Earth's atmosphere was undoubtedly different from that of today. Atmospheric oxygen levels were increasing from the primordial anoxic atmosphere due, for example, to cyanobacterial oxygenic photosynthesis. Late Proterozoic (∼0.6–0.9 Gya) deep-ocean oxygen concentrations are less certain, but geochemical evidence suggests anoxia and hydrogen-sulfide enrichment. It can, therefore, be postulated that initial eukaryotic diversification occurred in oxygen-depleted, sulfide-enriched environments. Foraminifera are aerobes and, thus, not expected in anoxic settings. Recently, however, we found a saccamminid allogromian in a deep-water anoxic, sulfidic setting. Samples were collected from Santa Barbara Basin (California) when bottom-water oxygen was undetectable and sediments smelled strongly of hydrogen sulfide. Foraminiferal SSU rDNA sequences recovered from sediments included one from a previously uncharacterized saccamminid. Ultrastructural analysis indicated the presence of intact Golgi, mitochondria, and prokaryotic endobionts. Saccamminid occurrence in environmental conditions known to exist during the Proterozoic supports the possibility of their origin early in eukaryotic evolution. Extant saccamminids could have competed well in the prokaryote-dominated Proterozoic benthic ecosystem given their diet includes bacteria, bacterial biofilms and unicellular algae. Thus, Proterozoic foraminifers may have been top carnivores.Funded by NASA NRA-01-01-EXB-057, the Geological Society of America's W. Storrs Cole Memorial Research Award, and NSF OPP0003639.
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    [s.l.] : Macmillian Magazines Ltd.
    Nature 403 (2000), S. 77-80 
    ISSN: 1476-4687
    Source: Nature Archives 1869 - 2009
    Topics: Biology , Chemistry and Pharmacology , Medicine , Natural Sciences in General , Physics
    Notes: [Auszug] It is generally agreed that the origin and initial diversification of Eucarya occurred in the late Archaean or Proterozoic Eons when atmospheric oxygen levels were low and the risk of DNA damage due to ultraviolet radiation was high. Because deep water provides refuge against ultraviolet ...
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    Springer
    Biogeochemistry 15 (1991), S. 127-149 
    ISSN: 1573-515X
    Keywords: anoxia ; ATP ; foraminifera ; geochemistry ; organic-rich sediments ; ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Geosciences
    Notes: Abstract The pore-water geochemistry and benthic foraminiferal assemblages of sediments from two slope sites and within the central portion of the Santa Barbara Basin were characterized between February 1988 and July 1989. The highest foraminiferal numerical densities (1197 cm−3 as determined by an ATP assay) occurred at a slope site in June 1988 (550 m) in partially laminated sediments. In continuously laminated sediments from the central basin, foraminifera were found living (as determined by ATP assay) in October 1988 to depths of 4 cm, and specimens prepared for transmission electron microscopy were found with intact organelles to 3 cm, indicating their inhabitation of anoxic pore waters. Ultrastructural data from Nonionella stella is consistent with the hypothesis that this species can survive by anaerobic respiration. However, the benthic foraminifera appear unable to survive prolonged anoxia. The benthic foraminiferal population was completely dead in July 1989 when bottom water O2 was undetectable.
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  • 6
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    Unknown
    PANGAEA
    In:  Supplement to: van Geen, Alexander; Zheng, Y; Bernhard, Joan M; Cannariato, Kevin G; Carriquiry, José D; Dean, Walter E; Eakins, B W; Ortiz, Joseph D; Pike, Jennifer (2003): On the preservation of laminated sediments along the western margin of North America. Paleoceanography, 18(4), 1098, https://doi.org/10.1029/2003PA000911
    Publication Date: 2023-05-12
    Description: Piston, gravity, and multicores as well as hydrographic data were collected along the Pacific margin of Baja California to reconstruct past variations in the intensity of the oxygen-minimum zone (OMZ). Gravity cores collected from within the OMZ north of 24°N did not contain laminated surface sediments even though bottom water oxygen (BWO) concentrations were close to 5 µmol/kg. However, many of the cores collected south of 24°N did contain millimeter- to centimeter-scale, brown to black laminations in Holocene and older sediments but not in sediments deposited during the Last Glacial Maximum. In addition to the dark laminations, Holocene sediments in Soledad Basin, silled at 290 m, also contain white coccolith laminae that probably represent individual blooms. Two open margin cores from 430 and 700 m depth that were selected for detailed radiocarbon dating show distinct transitions from bioturbated glacial sediment to laminated Holocene sediment occurring at 12.9 and 11.5 ka, respectively. The transition is delayed and more gradual (11.3-10.0 ka) in another dated core from Soledad Basin. The observations indicate that bottom-water oxygen concentrations dropped below a threshold for the preservation of laminations at different times or that a synchronous hydrographic change left an asynchronous sedimentary imprint due to local factors. With the caveat that laminated sections should therefore not be correlated without independent age control, the pattern of older sequences of laminations along the North American western margin reported by this and previous studies suggests that multiple patterns of regional productivity and ventilation prevailed over the past 60 kyr.
    Keywords: Age, 14C AMS; Age, 14C calibrated; Age, comment; Age, dated; Age, dated standard error; Calendar age; Calendar age, standard error; Depth, relative; DEPTH, sediment/rock; Elevation of event; Event label; GC; Gravity corer; Latitude of event; Longitude of event; Melville; MUC; MultiCorer; North Pacific/Gulf of California; OXMZ01MV; OXMZ01MV-GC31; OXMZ01MV-GC32; OXMZ01MV-GC38; OXMZ01MV-GC41; OXMZ01MV-MC17; OXMZ01MV-MC19; OXMZ01MV-PC08; OXMZ01MV-PC09; OXMZ01MV-PC10; OXMZ01MV-PC14; PC; Piston corer; Reservoir age; Reservoir age, standard error; Sample code/label
    Type: Dataset
    Format: text/tab-separated-values, 438 data points
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  • 7
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    Unknown
    PANGAEA
    In:  Supplement to: McIntyre-Wressnig, Anna; Bernhard, Joan M; Wit, Johannes C; McCorkle, Daniel C (2014): Ocean acidification not likely to affect the survival and fitness of two temperate benthic foraminiferal species: results from culture experiments. Journal of Foraminiferal Research, 44(4), 341-351, https://doi.org/10.2113/gsjfr.44.4.341
    Publication Date: 2024-03-15
    Description: Specimens of Bolivina argentea and Bulimina marginata, two widely distributed temperate benthic foraminiferal species, were cultured at constant temperature and controlled pCO2 (ambient, 1000 ppmv, and 2000 ppmv) for six weeks to assess the effect of elevated atmospheric CO2 concentrations on survival and fitness using Adenosine Triphosphate (ATP) analyses and on shell microfabric using high-resolution SEM and image analysis. To characterize the carbonate chemistry of the incubation seawater, total alkalinity and dissolved inorganic carbon were measured approximately every two weeks. Survival and fitness were not directly affected by elevated pCO2 and the concomitant decrease in seawater pH and calcite saturation states (Omega c), even when seawater was undersaturated with respect to calcite. These results differ from some previous observations that ocean acidification can cause a variety of effects on benthic foraminifera, including test dissolution, decreased growth, and mottling (loss of symbiont color in symbiont-bearing species), suggesting that the benthic foraminiferal response to ocean acidification may be species specific. If so, this implies that ocean acidification may lead to ecological winners and losers even within the same taxonomic group.
    Keywords: Adenosine 5-Triphosphate; Alkalinity, total; Aragonite saturation state; Benthos; Bicarbonate ion; Bolivina argentea; Bottles or small containers/Aquaria (〈20 L); Bulimina marginata; Calcite saturation state; Calculated using CO2SYS; Calculated using seacarb after Nisumaa et al. (2010); Carbon, inorganic, dissolved; Carbonate ion; Carbonate system computation flag; Carbon dioxide; Chromista; Coast and continental shelf; Coulometric titration; Date; EXP; Experiment; Foraminifera; Fugacity of carbon dioxide (water) at sea surface temperature (wet air); Heterotrophic prokaryotes; Incubation duration; Laboratory experiment; Mortality/Survival; Mud_Patch; Not applicable; OA-ICC; Ocean Acidification International Coordination Centre; Partial pressure of carbon dioxide (water) at sea surface temperature (wet air); pH; Potentiometric titration; Salinity; Single species; Species; Survival; Temperate; Temperature, water; Treatment
    Type: Dataset
    Format: text/tab-separated-values, 783 data points
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  • 8
    Publication Date: 2024-03-15
    Description: Agglutinated foraminifera create a shell by assembling particles from the sediment and comprise a significant part of the foraminiferal fauna. Despite their high abundance and diversity, their response to environmental perturbations and climate change is relatively poorly studied. Here we present results from a culture experiment with four different species of agglutinating foraminifera incubated in artificial substrate and exposed to different pCO2 conditions, in either dysoxic or oxic settings. We observed species-specific reactions (i.e., reduced or increased chamber formation rates) to dysoxia and/or acidification. While chamber addition and/or survival rates of Miliammina fusca and Trochammina inflata were negatively impacted by either dysoxia or acidification, respectively, Textularia tenuissima and Spiroplectammina biformis had the highest survivorship and chamber addition rates with combined high pCO2 (2000 ppm) and low O2 (0.7 ml/l) conditions. The differential response of these species indicates that not all agglutinating foraminifera are well-adapted to conditions induced by predicted climate change, which may result in a shift in foraminiferal community composition.
    Keywords: Alkalinity, total; Alkalinity, total, standard deviation; Aragonite saturation state; Aragonite saturation state, standard deviation; Benthos; Bicarbonate ion; Bicarbonate ion, standard deviation; Bottles or small containers/Aquaria (〈20 L); Calcite saturation state; Calcite saturation state, standard deviation; Calculated using CO2SYS; Calculated using seacarb after Nisumaa et al. (2010); Calculated using seacarb after Orr et al. (2018); Carbon, inorganic, dissolved; Carbon, inorganic, dissolved, standard deviation; Carbonate ion; Carbonate ion, standard deviation; Carbonate system computation flag; Carbon dioxide; Carbon dioxide, standard deviation; Chamber number; Chromista; Coast and continental shelf; EXP; Experiment; Foraminifera; Fugacity of carbon dioxide (water) at sea surface temperature (wet air); Fugacity of carbon dioxide in seawater, standard deviation; Growth/Morphology; Heterotrophic prokaryotes; Laboratory experiment; Miliammina fusca; Mortality/Survival; Mudpatch; North Pacific; Number of specimens; OA-ICC; Ocean Acidification International Coordination Centre; Oxygen; Oxygen, dissolved; Partial pressure of carbon dioxide, standard deviation; Partial pressure of carbon dioxide (water) at sea surface temperature (wet air); Percentage; pH; pH, standard deviation; Potentiometric titration; Registration number of species; Salinity; Single species; Species; Species interaction; Spiroplectammina biformis; Survival; Temperate; Temperature, water; Temperature, water, standard deviation; Textularia tenuissima; Treatment; Trochammina inflata; Type; Uniform resource locator/link to reference
    Type: Dataset
    Format: text/tab-separated-values, 586 data points
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  • 9
    Publication Date: 2024-03-15
    Description: Ocean chemistry is changing as a result of human activities. Atmospheric carbon dioxide (CO2) concentrations are increasing, causing an increase in oceanic pCO2 that drives a decrease in oceanic pH, a process called ocean acidification (OA). Higher CO2 concentrations are also linked to rising global temperatures that can result in more stratified surface waters, reducing the exchange between surface and deep waters; this stronger stratification, along with nutrient pollution, contributes to an expansion of oxygen-depleted zones (so called hypoxia or deoxygenation). Determining the response of marine organisms to environmental changes is important for assessments of future ecosystem functioning. While many studies have assessed the impact of individual or paired stressors, fewer studies have assessed the combined impact of pCO2, O2, and temperature. A long-term experiment (10 months) with different treatments of these three stressors was conducted to determine their sole or combined impact on the abundance and survival of a benthic foraminiferal community collected from a continental-shelf site. Foraminifera are well suited to such study because of their small size, relatively rapid growth, varied mineralogies and physiologies. Inoculation materials were collected from a 77-m deep site south of Woods Hole, MA. Very fine sediments (〈53 μm) were used as inoculum, to allow the entire community to respond. Thirty-eight morphologically identified taxa grew during the experiment. Multivariate statistical analysis indicates that hypoxia was the major driving factor distinguishing the yields, while warming was secondary. Species responses were not consistent, with different species being most abundant in different treatments. Some taxa grew in all of the triple-stressor samples. Results from the experiment suggest that foraminiferal species' responses will vary considerably, with some being negatively impacted by predicted environmental changes, while other taxa will tolerate, and perhaps even benefit, from deoxygenation, warming and OA.
    Keywords: Alkalinity, total; Alkalinity, total, standard deviation; Aragonite saturation state; Benthos; Bicarbonate ion; Bottles or small containers/Aquaria (〈20 L); Calcite saturation state; Calcite saturation state, standard deviation; Calculated using CO2SYS; Calculated using seacarb after Nisumaa et al. (2010); Carbon, inorganic, dissolved; Carbon, inorganic, dissolved, standard deviation; Carbonate ion; Carbonate ion, standard deviation; Carbonate system computation flag; Carbon dioxide; Coast and continental shelf; Community composition and diversity; Entire community; EXP; Experiment; Fugacity of carbon dioxide (water) at sea surface temperature (wet air); Laboratory experiment; Manometric; New_England_continental_shelf; North Atlantic; OA-ICC; Ocean Acidification International Coordination Centre; Oxygen; Oxygen, dissolved; Partial pressure of carbon dioxide, standard deviation; Partial pressure of carbon dioxide (water) at sea surface temperature (wet air); pH; pH, standard deviation; Potentiometric titration; Replicate; Salinity; Sample ID; Shannon Diversity Index; Soft-bottom community; Species; Species richness; Specimen count; Temperate; Temperature; Temperature, water; Treatment; Type
    Type: Dataset
    Format: text/tab-separated-values, 50320 data points
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  • 10
    Publication Date: 2008-09-08
    Description: Laboratory cultures of several species of benthic foraminifera were grown under controlled physical and chemical conditions during months-long experiments carried out at the University of South Carolina in 2001 and 2002. A dozen experimental culture chambers contained a c. 1-3 mm layer of trace-metal free silica substrate, and were continuously flushed with water from a large (1600 L) seawater reservoir with known, constant temperature and composition ({delta}18O(water), carbonate system chemistry, and trace element concentrations). Each year, in most of the culture chambers, one or more species reproduced, producing hundreds of juveniles which grew into size classes ranging from 100 to 500 microns. Bulimina aculeata was the most successful species in the 2001 cultures, and both B. aculeata and Rosalina vilardeboana were abundant in 2002. We determined the shell C and O isotopic composition of the cultured foraminifera, and compared these isotopic values with the water chemistry of the culture chambers, and also with the shell chemistry of field specimens collected from sites on the North Carolina and South Carolina (USA) continental margin. The cultured foraminifera showed substantial offsets from the {delta}13C of system water dissolved inorganic carbon (-0.5 to -2.5{per thousand}, depending on species) and smaller offsets (0 to -0.5{per thousand}) from the predicted {delta}18O of calcite in equilibrium with the culture system water at the growth temperature. These offsets reflect at least three factors: species-dependent vital effects; ontogenetic variations in shell chemistry; and the aqueous carbonate chemistry ([CO3-] or pH) of the experimental system.
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