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Mediterranean Foraminifera

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Bibliogr. s. 88-96. - Slovin. souhrn
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... The picking and the identification of the foraminifera were performed under a ZEISS Olympus SZ61 stereo microscope equipped with a high-resolution camera. The taxonomic determination of the foraminifera was based on Cimerman and Langer (1991), Langer and Schmidt-Sinns (2006), Milker and Schmiedl (2012), the Foraminifera.eu-Project (Hesemann, 2020), and World Register of Marine Species (WoRMS Editorial Board, 2021). ...
... The relative frequency of this morphotype is low in all the samples, and no members of this group were observed in F7. The highest value, 1.5%, was recorded in sample P10, which was collected from the dark-coloured sediment within a Posidonia-bearing layer ( Cimerman and Langer, 1991), C. cf. magellanicum and A. stelligerum. ...
Article
Well-preserved remains of a Posidonia oceanica meadow have been found in a lower Pleistocene (Calabrian) succession cropping out near Fauglia (Tuscany, Italy). This paper analyses and describes the benthic foraminiferal community associated with this well-preserved Pleistocene P. oceanica meadow, with the purpose of testing the usefulness of foraminifera as an Indirect Palaeo-Seagrass Indicator (IPSI), providing both qualitative and quantitative parameters to recognize other meadow-related environments where fossil remains of seagrasses are not preserved. Despite being influenced by some diagenetic processes that might have affected the foraminiferal assemblage, the Fauglia succession represents a suitable setting for testing benthic foraminifera as IPSI in a temperate environment. Considering this limitation, together with other ecological constraints such as seawater temperature, this study provides evidence of the high potential of benthic foraminifera as IPSI. Several parameters such as the modified Foraminifera Index (FI’), the “long vs. short life-span index” (ILS), and the presence of permanently attached, encrusting foraminifera were tested. New indexes were also developed, namely the K/R ratio, consisting of the ratio between keeled Elphidium and the sum of rounded elphidiids (e.g., Elphidium translucens, Cribroelphidium, Porosononion) and Haynesina, and the K/REXT ratio, consisting of the ratio between keeled Elphidium and the sum of rounded elphidiids, Haynesina and other related genera that display a rounded periphery (i.e., Astrononion, Melonis, Nonion, Nonionella, Valvulineria). All these indexes were examined, suggesting their potential use for recognizing seagrass-related palaeoenvironments. The K/REXT ratio (and K/R) in association with the presence of permanently attached foraminifera revealed to be the most reliable palaeo-seagrass indicators, suggesting that this combination could be very useful also in other case studies where diagenesis altered the foraminiferal association.
... However, in the Mediterranean region, many studies (e.g. Cimerman and Langer, 1991;Sgarrella and Zei, 1993;Mojtahid et al., 2009) have addressed the compositional and microhabitat zonation of the shelf foraminiferal assemblages, where the epibiotic living mode is widespread among the reported taxa. Indeed, this is probably the most extended strategy in the shallowest settings where the foraminiferal assemblage mostly corresponds to the epibiotic biocoenosis of Posidonia oceanica meadows (Langer and Schmidt-Sinns, 2006;Frezza et al., 2011;Mateu-Vicens et al., 2010El Kateb et al., 2020). ...
... Scanning electron microscopy (SEM) images of each morphotype were taken to be used in species identification. A set of previous studies on this group in the western Mediterranean and the eastern coast of Spain (Cimerman and Langer, 1991;Colom, 1974;Dorst and Schönfeld, 2015;Milker and Schmiedl, 2012) were used for the identification of species and the taxonomic criteria of the WORMS database have been followed for updated nomenclature. Rather than cardboard slides commonly used with microfossils, specimens of the present study remain stored in 70% ethanol at the Department of Biology (University of Seville). ...
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Coralligenous habitats represent the main biodiversity hotspot in the Mediterranean Sea and foraminifera constitute a key element in this environment, both in terms of species richness and ecological functionality. Despite this, species composition and distribution trends of foraminiferal assemblages in most Mediterranean regions are poorly known. In this sense, the present study explores the diversity and the spatial distribution patterns (i.e. host and environmental specificity) of benthic foraminifera inhabiting coralligenous habitats of the Strait of Gibraltar. Four different dominant substrates were considered: the macroalgae Sphaerococcus coronopifolius and Rugulopteryx okamurae, the sponge Spongia lamella and the gorgonian Paramuricea clavata. Four replicate samples of each host substrate were collected by SCUBA diving at three different stations with marked differences in their Atlantic/Mediterranean influence. The whole epifaunal community was sorted and a total of 120 foraminifera specimens were collected, belonging to five genera: Cibicidoides, Elphidium, Eponides, Massilina and Poroeponides. According to the statistical analyses conducted, epibiotic foraminiferal assemblages was homogeneous across host substrates and study locations. Despite the absence of significant differences among factors in terms of abundance and species richness, certain species such as Eponides repandus or Elphidium macellum showed spatial trends related to their spatial distribution (North vs South Bay), that could be attributed to environmental fluctuations (tempertature, hydrodynamism) derived from the transition between Atlantic and Mediterranean conditions in the Strait of Gibraltar.
... Species and their ecological characteristics were determined based on previous studies of Mediterranean benthic taxa (e.g. Cimerman and Langer, 1991; Relative volumes of the Stereo-atlas of ostracod shells; Meisch, 2000). Species were grouped based on their ecological characteristics. ...
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... For samples in which there were <300 specimens, all tests and valves were picked. Species were identified according to Cimerman and Langer (1991) and Meriç et al. (2004) for foraminifera, and following Bonaduce et al. (1975) and Joachim and Langer (2008) for ostracoda. ...
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