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We describe a new agglutinated monothalamous foraminiferal species, Capsammina crassa sp. nov., based on integrated observations of the test morphology and the chemical characteristics of materials composing the test. The new species was found at a depth of <60 m on the East coast of Korea. The test morphology is typical of the genus Capsammina, comprising two or more mica plates with a ring of finely agglutinated mineral grains sandwiched between them and surrounding the cell body. There is no distinct test aperture. Elemental analyses of the agglutinated grains revealed 15 different types of mineral grains of which quartz is the most abundant. The surface areas of grains exposed on fractured surfaces ranged from 1.6 to 7,700 µm² and the large plate-like grains forming the upper and lower surfaces measured about 420-2,350 µm in maximum width. The new species is morphologically similar to C. patelliformis, however, the differences in size, distribution area and depth support that these two species are distinct. This discovery is the first record of the genus Capsammina from the North Pacific. Therefore, it extends the biodiversity and geographical distribution of the genus Capsammina, which has been reported only from the bathyal NE Atlantic. Our finding also suggests the possibility of additional discovery of monothalamous foraminifera from around Korea. [ABSTRACT FROM AUTHOR]

Abstract: The use of an ESEM–EDS (Environmental Scanning Electron Microscope coupled with an Energy Dispersive X-ray Spectrometer), refined and corrected by point Raman micro-analyses, enables a rapid and representative overview of the mineral diversity of agglutinated foraminiferal tests. Statistical analyses of chemical data for ca. 180 tests and ca. 720 grains are used to evaluate environmental influences on test formation. While some species of the genus Textularia are known to select specific grains for their test, no statistically significant differences in grain selection are observed, at the genus level. The test chemistry is controlled by the availability of minerals and, therefore by the area's geological setting. Due to the active tectonic setting of the Aegean and Marmara Seas, the agglutinated tests of this area are characterised by a high content of fresh mafic feldspar and amphibole. [Copyright &y& Elsevier]

Abstract: The study of benthic foraminifera in a complex marine system, like the Marmara Sea, is a key for understanding the influence of environmental factors on foraminiferal species, density, assemblage composition, and shell construction. This kind of study is important for further extensive use of foraminifera-based investigation of water mass and sediment exchange between the eastern Mediterranean and Black Sea through the Marmara Sea. Based on proximal–distal transect from the southwest coast of the Erdek Bay to the top of canyon close to the North Anatolian Fault, this study aims at defining the geochemical conditions at the seafloor and identifying the sediment constraints that act upon agglutinated test construction for selected species (Eggerelloides scaber, Textularia agglutinans, Textularia sagittula, Textularia truncata and Textularia bocki). Grain size, mineralogical, and chemical analyses of their shells were investigated and confronted with the main geochemical conditions prevailing during deposition and within the sediment. Among grains used to construct the agglutinated foraminiferal tests from available grains, both grain size selection and sorting have been evidenced. This suggests that the mineralogical composition is related to the species and the sample localization within the basin. Our observations further suggest that bottom water conditions of the Marmara Sea do not have a significant influence on agglutinated foraminiferal shell development, which is primarily driven by sediment characteristics. Our results are thus transposable to other environments. [Copyright &y& Elsevier]