28 pubblicazioni classificate nel seguente modo:

Nr. doc. Classificazioni
25 1 Contributo su Rivista
2 2 Contributo in Volume
1 4 Contributo in Atti di Convegno (Proceeding)
Anno Risorsa
2019 Living foraminiferal assemblages in two submarine canyons (Polcevera and Bisagno) of the Ligurian basin (Mediterranean Sea)
Autore/i: Di Bella, L.; Sabbatini, A.; Carugati, L.; Lo Martire, M.; Luna, G. M.; Pierdomenico, M.; Danovaro, R.; Negri, A.
Classificazione: 1 Contributo su Rivista
Abstract: Living (Rose-Bengal stained) benthic foraminifera were investigated in eleven stations sampled along transects following a depth gradient from Polcevera and Bisagno canyons and the adjacent open slope (Ligurian Sea), in a depth interval ranging from 200 to 2000 m. In order to understand which environmental factors influence the abundance and taxonomical composition of the foraminiferal assemblages in these two domains (canyon and open slope), qualitative and quantitative foraminiferal data were correlated to the sediment biochemical composition (in terms of phytopigments, proteins, lipids, carbohydrates and biopolymeric carbon), grain size and the main hydrological characteristics (salinity, temperature, dissolved oxygen). The Cluster Analysis and Canonical Correspondence Analysis allowed us to detect two sectors (coastal and offshore) characterized by contrasting trophic conditions. The coastal sector reflects spread meso-eutrophic conditions in both physiographic domains being possibly more impacted by the river inputs and sediment transport processes from land. In fact, the narrow continental shelf of the Ligurian Sea favors the deposition of sediment transported by riverine processes on the immediately adjacent coastal areas. As a result homogenization of sea-bottom conditions occurs, leading to an unclear differentiation between open slope and canyon foraminiferal assemblages. Conversely, the offshore sector is less affected by physical disturbance due to the sedimentary flows decreasing in relation to the larger distance from the coastline. Consequently, the lower organic matter content and lower food quality (expressed in terms of contribution of the primary material to the biopolymeric carbon pool) lead to a more oligotrophic condition, which favors the development of peculiar assemblages dominated by Glomospira charoides, Ammolagena clavata and epifaunal taxa. The first finding ever of a warm tropical species (Amphistegina lessonii) in the Ligurian Sea sediments at 500-m depth can be considered the first evidence of upward expansion of tropical species to the Northern portion of the Mediterranean Sea, which is experiencing an evident water warming linked to the ongoing global climate change.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/264513 Collegamento a IRIS

2018 Benthic foraminiferal assemblages in the Cap de Creus canyon and adjacent open slope: Potential influence of dense shelf water cascading and open-ocean convection
Autore/i: Nardelli, M. P.; Sabbatini, A.; Bonnot, E.; Mea, M.; Pusceddu, A.; Danovaro, R.; Durrieu de Madron, X.; Negri, A.; Bicchi, E.
Classificazione: 1 Contributo su Rivista
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/259250 Collegamento a IRIS

2018 Developing Foram-AMBI for biomonitoring in the Mediterranean: Species assignments to ecological categories
Autore/i: Jorissen, Frans; Pia Nardelli, Maria; Almogi-Labin, Ahuva; Barras, Christine; Bergamin, Luisa; Bicchi, Erica; El Kateb, Akram; Ferraro, Luciana; Mcgann, Mary; Morigi, Caterina; Romano, Elena; Sabbatini, Anna; Schweizer, Magali; Spezzaferri, Silvia
Classificazione: 1 Contributo su Rivista
Abstract: Most environmental bio-monitoring methods using the species composition of marine faunas define the Ecological Quality Status of soft bottom ecosystems based on the relative proportions of species assigned to a limited number of ecological categories. In this study we analyse the distribution patterns of benthic foraminifera in the Mediterranean as a function of organic carbon gradients on the basis of 15 publications and assign the individual species to five ecological categories. Our categories (of sensitive, indifferent and 3rd, 2nd and 1st order opportunists) are very similar to the ecological categories commonly used for macrofauna, but show some minor differences. In the 15 analysed publications, we considered the numerical data of 493 taxa, of which 199 could be assigned. In all 79 taxa were classified as sensitive, 60 as indifferent, 46 as 3rd order, 12 as 2nd order and 2 as 1st order opportunists. The remaining 294 taxa are all accessory, and will only marginally contribute to biotic indices based on relative species proportions. In this paper we wanted also to explain the methodology we used for these species assignments, paying particular attention to all complications and problems encountered. We think that the species list proposed here will constitute a highly useful tool for foraminiferal bio-monitoring of soft bottoms in the Mediterranean Sea, which can be used in different ecological indices (Foram-AMBI and similar methods). With additional information becoming available in the next few years, it will be possible to expand the list, and, if necessary, to apply some minor corrections. As a next step, we intend to test this species list using several biotic indices, in a number of independent data sets, as soon as these will become available.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/254644 Collegamento a IRIS

2018 Benthic foraminiferal ultrastructural alteration induced by heavy metals
Autore/i: Frontalini, F.; Nardelli, M. P.; Curzi, D.; Martín-gonzález, A.; Sabbatini, Anna; Negri, Alessandra; Losada, M. T.; Gobbi, P.; Coccioni, R.; Bernhard, J. M.
Classificazione: 1 Contributo su Rivista
Abstract: Heavy metals are known to cause deleterious effects on biota because of their toxicity, persistence and bioaccumulation. Here, we briefly document the ultrastructural changes observed in the miliolid foraminifer Pseudotriloculina rotunda (d'Orbigny in Schlumberger, 1893) and in the perforate calcareous species Ammonia parkinsoniana (d'Orbigny, 1839) induced by exposure to one of three heavy metals (zinc, lead, or mercury). The exposure of these two benthic foraminiferal species to the selected heavy metals appears to promote cytological alterations and organelle degeneration. These alterations include a thickening of the inner organic lining, an increase in number and size of lipid droplets, mitochondrial degeneration, and degradation vacuoles and residual body proliferation. Some of these alterations, including the thickening of the inner organic lining and the proliferation of lipids, might represent defense mechanisms against heavy metal-induced stress.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/251812 Collegamento a IRIS

2016 Selective zircon accumulation in a new benthic foraminifer, Psammophaga zirconia, sp. nov.
Autore/i: Sabbatini, Anna; Negri, Alessandra; Bartolini, A.; Morigi, C.; Boudouma, O.; Dinelli, E.; Florindo, F.; Galeazzi, Roberta; Holzmann, M.; Lurcock, P. C.; Massaccesi, Luca; Pawlowski, J.; Rocchi, S.
Classificazione: 1 Contributo su Rivista
Abstract: Benthic foraminifera are single-celled eukaryotes that make a protective organic, agglutinated or calcareous test. Some agglutinated, single-chambered taxa, including Psammophaga Arnold, 1982, retain mineral particles in their cytoplasm, but the selective mechanism of accumulation is not clear. Here, we report the ability of a foraminiferal species to select and accumulate zircons and other heavy minerals in their cytoplasm. In particular, the use of Scanning Electron Microscope coupled with an Energy Dispersive X-ray microanalysis system (SEM–EDS) enabled a representative overview of the mineral diversity and showed that the analysed Psammophaga zirconia sp. nov. individuals contained dominantly crystals of zircon (51%), titanium oxides (27%), and ilmenite (11%) along with minor magnetite and other minerals. The studied specimens occur in the shallow central Adriatic Sea where the sediment has a content of zircon below 1% and of other heavy minerals below 4%. For that reason we hypothesize that: (i) P. zirconia may be able to chemically select minerals, specifically zircon and rutile; (ii) the chemical mechanism allowing the selection is based on electrostatic interaction, and it could work also for agglutinated foraminifera (whether for ingestion, like Xenophyophores, or incorporation in the test as in many other described taxa). In particular, this aptitude for high preferential uptake and differential ingestion or retention of zircon is reported here for the first time, together with the selection of other heavy minerals already described in members of the genus Psammophaga. They are generally counted among early foraminifera, constructing a morphologically simple test with a single chamber. Our molecular phylogenetic study confirms that P. zirconia is a new species, genetically distinctive from other Psammophaga, and occurs in the Adriatic as well as in the Black Sea.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/235947 Collegamento a IRIS

2016 Grounding-zone wedges and mega-scale glacial lineations in Kveithola Trough, Barents Sea
Atlas of Submarine Glacial Landforms: Modern, Quaternary and Ancient
Autore/i: Rebesco, M; Urgeles, R.; Özmaral, A.; Hanebuth, T. J. J.; Lantzsch, H.; Caburlotto, A.; Hörner, T.; Llopart, J.; Lucchi, R. G.; Nicolaisen, L. S.; Osti, G.; Sabbatini, Anna
Editore: Geological Society of London
Luogo di pubblicazione: London
Classificazione: 2 Contributo in Volume
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/245789 Collegamento a IRIS

2016 Zinc incorporation in the miliolid foraminifer Pseudotriloculina rotunda under laboratory conditions
Autore/i: Nardelli, M.P.; Malferrari, D.; Ferretti, A.; Bartolini, A.; Sabbatini, A.; Negri, A.
Classificazione: 1 Contributo su Rivista
Abstract: The incorporation rate of Zn into the calcareous tests of Pseudotriloculina rotunda was investigated in culture in order to evaluate the possibility of using Zn/Ca ratios as a pollution proxy. Foraminifera were incubated at zinc concentrations up to 10-fold higher than unpolluted seawater (sea + 10 mg Zn/L) during 70 days. New calcite was investigated under the Environmental Scanning Electron Microscope (ESEM), for potential alteration of test structure. Laser ablation-Inductively Coupled Plasma-Mass spectrometry (LA-ICP-MS) was used to quantify Zn contents. The analyses revealed that test structure is not visibly altered by the presence of zinc. However, significant Zn incorporation is detected by the LA-ICP-MS. The zinc partition coefficient, DZn, decreases at increasing Zn concentrations (from 4.03 ± 0.06 to 0.2 ± 0.01) and the zinc is incorporated into the calcite not necessarily linearly.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/235948 Collegamento a IRIS

2014 13. Foraminifera
The Mediterranean sea: Its history and present challenges
Autore/i: A. Sabbatini; Morigi C.; Nardelli M.P; A. Negri
Editore: Springer Netherlands
Luogo di pubblicazione: Amsterdam
Classificazione: 2 Contributo in Volume
Abstract: Foraminifera are eukaryotic unicellular microorganisms inhabiting all marine environments. The study of these protists has huge potential implications and benefits. They are good indicators of global change and are also promising indicators of the environmental health of marine ecosystems. Nevertheless, much remains to be learnt about foraminiferal ecology. In this chapter we intend to introduce the main issues in the study of foraminifera in the Mediterranean Sea and the state-of-the-art developments in the study of these organisms. The aims of this chapter are: (1) to provide a brief history of the study of foraminifera and (2) to review recent developments in the study of modern foraminifera, particularly as they apply to Mediterranean faunas. Our intention is to describe the development of the use of foraminiferal assemblages in Mediterranean applied ecological studies up to their possible use as bio-indicator for the monitoring of marine ecosystems.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/128679 Collegamento a IRIS

2014 Unraveling tectonic and climatic controls on synorogenic growth strata (Northern Apennines, Italy)
Autore/i: Kellen L. Gunderson; Frank J. Pazzaglia; Vincenzo Picotti; David A. Anastasio; Kenneth P. Kodama; Tammy Rittenour; Kurt F. Frankel; Alessio Ponza; Claudio Berti; Alessandra Negri; Anna Sabbatini
Classificazione: 1 Contributo su Rivista
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/144280 Collegamento a IRIS

2014 Biomineralization of Schlumbergerella floresiana, a significant carbonate-producing benthic foraminifer
Autore/i: Sabbatini A; Bédouet L; Marie A; Bartolini AC; Landemarre L; Weber M; Mahardika IGNK; Berland S; Zito F; Vénec-Peyré MT
Classificazione: 1 Contributo su Rivista
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/177905 Collegamento a IRIS

2014 Biostratigraphy as a Tool to Validate High-Resolution OSL, CRN, and Sequence-Stratigraphic Data
Strati 2013 First International Congress on Stratigraphy At the Cutting Edge of Stratigraphy
Autore/i: Negri, Alessandra; Sabbatini, Anna; Capozzi, R.; Gunderson, K.; Picotti, V.; Ponza, A.; Pazzaglia, F. J.
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/177907 Collegamento a IRIS

2013 Contribution of Soft-shelled Monothalamous Taxa to Foraminiferal Assemblages in the Adriatic Sea
Autore/i: Sabbatini A.; Nardelli M.P.; Morigi C.; Negri A.
Classificazione: 1 Contributo su Rivista
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/112674 Collegamento a IRIS

2013 Experimental Chronic Exposure of the Foraminifer Pseudotriloculina rotunda to Zinc
Autore/i: Nardelli, MARIA PIA; Sabbatini, Anna; Negri, Alessandra
Classificazione: 1 Contributo su Rivista
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/112675 Collegamento a IRIS

2012 Foraminiferal biodiversity associated with cold-water coral carbonate mounds and open slope of SE Rockall Bank (Irish continental margin—NE Atlantic)
Autore/i: C. Morigi; A. Sabbatini; G. Vitale; I. Pancotti; A.J. Gooday; G.C.A. Duineveld; H.C. De Stigter; R. Danovaro; A. Negri
Classificazione: 1 Contributo su Rivista
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/65936 Collegamento a IRIS

2012 Foraminiferal assemblages and trophic state in coastal sediments of the Adriatic Sea
Autore/i: Sabbatini, Anna; Bonatto, S.; Bianchelli, Silvia; Pusceddu, A.; Danovaro, Roberto; Negri, Alessandra
Classificazione: 1 Contributo su Rivista
Abstract: The environmental variables that influence the abundance and biodiversity of foraminifera in shallow-water settings are poorly understood. In order to help address this problem, we investigated abundance, biomass and biodiversity of living (as Rose-Bengal stained) benthic foraminifera together with the quantity and biochemical composition (in terms of phytopigment, protein, lipid, carbohydrate and biopolymeric carbon) of the organic matter in coastal sediments of the Central Adriatic Sea. Sediment samples were collected in the Portonovo Bay in May, July and October 2008 and February 2009, and the organic matter quantity and biochemical composition and benthic foraminiferal abundance and assemblage composition were analysed in the top 1 cm. Uni- and multi-variate analyses of variance revealed clear temporal variability of all the investigated variables as well as relationships between the composition of the foraminiferal assemblages and the quantity and quality of the food sources. The foraminiferal abundance and species composition changed significantly between the four sampling periods, reflecting the temporal (seasonal) variability in the quantity and nutritional quality of the food sources. Lipids, among all other organic compounds, explain significant portions of the variance of both foraminiferal abundance and biomass. In winter, a strong phytoplankton bloom led to an increased quantity of nutritionally available organic matter on the sea floor, which in turn was associated with a bloom of Leptohalysis scottii and Psammophaga sp. 1. These two foraminiferal species thus displayed an opportunistic behaviour in response to the pulse of organic carbon of high nutritional quality. We suggest that these species can be used as indicators of benthic eutrophication in shallow waters.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/80438 Collegamento a IRIS

2011 Technical Note: Determination of the metabolically active fraction of benthic foraminifera by means of Fluorescent In Situ Hybridization (FISH)
Autore/i: C. Borrelli; A. Sabbatini; G. M. Luna; M. P. Nardelli; T. Sbaffi; C. Morigi; R. Danovaro; A. Negri
Classificazione: 1 Contributo su Rivista
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/61539 Collegamento a IRIS

2011 Further constraints on the diagenetic influences and salinity effect on Globigerinoides ruber (white) Mg/Ca thermometry: Implications in the Mediterranean Sea
Autore/i: Sabbatini; A.; Bassinot F.; Boussetta S.; Negri A.; H. Rebaubier H.; Dewilde F.; Nouet J.; Caillon N.; Morigi C.
Classificazione: 1 Contributo su Rivista
Abstract: We analyzed Mg/Ca ratios of the planktonic species Globigerinoides ruber (white) picked from 49 box core samples covering the whole Mediterranean Sea and 2 core tops from the Atlantic Ocean. Over the entire data set, we found no significant correlation between Mg/Ca and d18O‐derived calcification temperatures. This lack of correlation is chiefly due to the presence of an early diagenetic, Mg‐rich calcite coating, which can constitute up to 20% of the total shell calcite in the central and eastern Mediterranean basin and result in anomalously high Mg/Ca values and a high scattering. In the western Mediterranean Sea, however, G. ruber Mg/Ca scattering shows smaller amplitude and Mg‐rich calcite remains under the XRD detection limit. SEM observations indicate that only a few samples are affected by trace amounts of post‐mortem calcite overgrowths (most of this calcite being likely removed during the chemical cleaning for Mg/Ca analyses). Using core top sediments from the western Mediterranean Sea, we performed an empirical calibration exercise, which confirms that G. ruber Mg/Ca is not only related to temperature but it is also significantly affected by sea surface salinity. This salinity effect is not specific to high salinity environments such as the Mediterranean Sea, since it appears to be coherent with recent results obtained on Indo‐Pacific and Atlantic surface sediments, which suggest that a +1 (psu) change in SSS results in a +1.7°C Mg/Ca‐temperature bias. This sensitivity to salinity is significantly higher than those deduced from culture experiments.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/62755 Collegamento a IRIS

2011 Diagenetic Mg-rich calcite in Mediterranean sediments: quantification and impact on foraminiferal Mg/Ca thermometry
Autore/i: Boussetta S.; Bassinot F.; Sabbatini A.; Caillon N.; Nouet J.; Kallel N.; Rebaubier H.; Klinkhammer G.; Labeyrie L.
Classificazione: 1 Contributo su Rivista
Abstract: Mg/Ca ratios in planktonic foraminifera have been developed into a powerful tool in paleoceanography to reconstruct past sea surface temperatures (SST). However, additional factors that might have an influence on Mg/Ca, like dissolution, salinity, diagenesis, and carbonate ion effects have come into focus. In this paper, the occurrence of diagenetic calcification and its potential effects on Mg/Ca have been studied using 20 wellpreserved core tops recovered from the Mediterranean Sea. Analyses were performed on two planktonic foraminifer species; Globigerinoides ruber and Globigerina bulloides using ICP-AES Mg/Ca measurements, SEM observations and X-ray diffractometry analyses. Foraminiferal Mg/Ca values are higher than those obtained in the open sea. The highest values were found in the Eastern Mediterranean basin. These anomalies cannot be simply explained by a salinity effect because Mg/ Ca ratios, when corrected for temperature influence, do not display any significant correlation with salinity. Our results seem to indicate that diagenesis can account for anomalously high Mg/Ca values. Indeed, SEM observations show aggregates of rhombohedral crystals that could be interpreted as secondary calcite overgrowths. We note also the occurrence of numerous coccoliths trapped in foraminifer walls and covered with a secondary mineral phase. X-ray diffraction diagrams of numerous foraminiferal samples exhibit peak of Mg-rich calcite (10–12%) associated with the usual foraminifer calcite peak. It has been demonstrated that this calcite highly rich in Mg, is compatible with an inorganic calcite precipitated directly from seawater. The deconvolution of the main XRD peak (104) shows that the percentage of Mg-rich calcite can reach up to ~21% of the total foraminiferal calcite in the Eastern basin whereas in the western Mediterranean Sea, proportions do not exceed 5%. In addition, we demonstrate that, the diagenetic process is very heterogeneous (even at the sample scale) and is not simply a reflection of ΔCO3 at the sea bottom. Thus, the high Mg/Ca ratios measured from Mediterranean Sea planktonic foraminifera does not appear to be caused by increased Mg uptake in a high salinity setting, but instead result chiefly from the presence of Mg rich calcite (10–12%) deposited during early diagenetic processes.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/55251 Collegamento a IRIS

Classificazione: 1 Contributo su Rivista
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/40765 Collegamento a IRIS

2010 Modern benthic foraminifers at Northern shallow sites of Adriatic Sea including soft-walled monothalamous taxa: a brief overview
Editore: Sheridan Press:PO Box 465:Hanover, PA 17331:(717)632-3535, EMAIL: pubsvc@tsp.sheridan.com, Fax: (717)633-8920
Classificazione: 1 Contributo su Rivista
Abstract: Sediment subsamples (0-2cm layer, >63μm fraction) from box cores taken at four sites (Stns 120, 121, 122, 123) located along a transect in theGulf of Trieste (water depth range 8-22m)were sorted for foraminifers, including soft-walledmonothalamous taxa (organic-walled allogromiids, agglutinated saccamminids and psammosphaerids). The distribution of foraminiferal species differed among samples, corresponding to differences in water depth, granulometry, distance from fresh water source and other chemical and physical parameters (temperature, salinity and dissolved oxygen). In general, the absolute and relative abundance of monothalamous foraminifers tended to decrease with distance from the coast, i.e. with distance from the inflow of the Isonzo River, whereas polythalamous taxa exhibited the opposite trend. Therewas also a switch in dominance by polythalamous agglutinated species at Stn 122 to polythalamous calcareous species at Stn 123. Among polythalamous foraminifers, the calcareous species Ammonia perlucida was dominant at the innermost station (Stn 120), together with the agglutinated species Cribrostomoides spp. and Haplophragmoides spp. These species were absent or less common at the other stations. Textularia agglutinans was abundant at the two inner stations (121, 122). Stn 122 was further characterized by Reophax nana, Leptohalysis scottii and the calcareous species Nonionella stella. The latter is also themost abundant taxa at the outer station (Stn 123) where the agglutinated taxa Reophax nana and Textularia conica are alsowell represented. All themonothalamous taxa found are previously unreported fromNorth Adriatic waters; all are undescribed at the species level and, in most cases, at the generic level also. Two genera (Psammophaga, Vellaria), however, are common in other shallow-water settings and Micrometula, previously known from habitats ranging from coastal to deep sea, is also present. One of the allogromiid morphotypes closely resembles Goodayia rostellaum, recently described from the Black Sea. Psammophaga and Vellaria are also known from the Black Sea, but the populations are probably distinct at the species level.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/30530 Collegamento a IRIS

2009 Molecular analyses reveal high levels of eukaryotic richness associated with enigmatic deep-sea protists (Komokiacea)
Autore/i: Lecroq B.; Gooday A. J.; Cedhagen T.; Sabbatini A.; Pawlowski J.
Classificazione: 1 Contributo su Rivista
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/55252 Collegamento a IRIS

2009 Survival of benthic foraminifera under hypoxic conditions: Results of an experimental study using the CellTracker Green method
Editore: Elsevier Science Limited:Oxford Fulfillment Center, PO Box 800, Kidlington Oxford OX5 1DX United Kingdom:011 44 1865 843000, 011 44 1865 843699, EMAIL: asianfo@elsevier.com, tcb@elsevier.co.UK, INTERNET: http://www.elsevier.com, http://www.elsevier.com/locate/shpsa/, Fax: 011 44 1865 843010
Classificazione: 1 Contributo su Rivista
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/30529 Collegamento a IRIS

2007 Distribution and biodiversity of stained monothalamous foraminifera from Tempelfjord, Svalbard
Editore: Cushman Foundation for Foraminiferal Research:MRC 121, Department of Paleobiology, Smithsonian Institute:Washington, DC 20560:(202)357-1390, EMAIL: jett.jennifer@nmnh.si.edu, INTERNET: http://cushforams.niu.edu, Fax: (202)786-2832
Classificazione: 1 Contributo su Rivista
Abstract: Live foraminiferal assemblages, including soft-walled monothalamous taxa (organic-walled allogromiids, agglutinated saccamminids and psammosphaerids) in addition to hard-shelled polythalamous forms, were analyzed at nine sites (26-104 m water depth) in Tempelfjord on the west coast of Svalbard. Small volumes of sediments (1 ml) were split into 63-125, 125-300 and >300 μm size fractions and each fraction was sorted for all stained foraminifera. There was a marked contrast in foraminiferal assemblages between the inner and outer parts of the fjord. Monothalamous foraminifera (88-97% of the live assemblage >63 μm) overwhelmingly dominated samples from the inner stations, located close to the glacier edge and, therefore, influenced by freshwater inputs. Multi-chambered agglutinated and calcareous taxa, on the other hand, were most common (77-82%) at the two outer stations. Many of the monothalamous foraminifera were organic-walled allogromiids. The dominant allogromiid was a tiny (30-60 μm) undescribed species, often with a distinctive cover of sediment particles, which ensured its retention on the 63-μm sieve. This species made up 31% of live foraminifera in all samples and 66% at one station near the glacier. Saccamminids and psammosphaerids were also common at some stations. A total of 63 monothalamous morphospecies was recognized with numbers at each station ranging from 7 (station 0763) to 19 (station 0758). Saccamminids at station 0759 were particularly diverse (12 morphospecies). Forms assigned to the genus Gloiogullmia represented 5-10% of the assemblage along the fjord, while the percentage of the genera Psammosphaga, Tinogullmia, and Micrometula was fairly consistent at all stations. These results provide further evidence of the importance of soft-walled, monothalamous foraminifera in sublittoral, high-latitude and brackish-water settings
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/30522 Collegamento a IRIS

2005 Benthic foraminiferal evidence for the formation of the Holocene mud-belt and bathymetrical evolution in the central Adriatic Sea
Autore/i: Morigi, C.; Jorissen, F. J.; Fraticelli, S.; Principi, M.; Sabbatini, Anna; Capotondi, L.; Curzi, P. V.; Horton, B. P.; Negri, Alessandra
Classificazione: 1 Contributo su Rivista
Abstract: Detailed analyses of modern and fossil benthic foraminiferal assemblages collected in the central Adriatic Sea are used as tools to reconstruct the environmental changes that occurred between the Last Deglaciation and the Present (last 14 Kyrs); in particular we focus on the timing and formation of the mud-belt. The modern benthic foraminiferal assemblages display a parallel zonation to the Italian coast controlled by the interaction between food/oxygen availability and water depth. Cluster analysis of 4 sediment cores separates the fossil foraminiferal assemblages in 6 groups: Cluster A is dominated by three Ammonia species; Cluster B consists of Ammonia papillosa, Nonionella turgida, Elphidium advenum and Elphidium decipiens; Cluster C is composed of two taxa, Hyalinea balthica and Trifarina angulosa; Cluster D is dominated by 5 species, Cibicides lobatulus, Buccella granulata, Reussella spinulosa, Textularia agglutinans and Elphidium crispum; Cluster E contains Bulimina spp., Gavelinopsis praegeri, Bolivina spp., Cassidulina neocarinata and Asterigerinata mamilla; and Cluster F is dominated by Bulimina marginata, Valvulineria bradyana, Globocassidulina subglobosa and Melonis padanum. The cluster analysis and contemporary distribution patterns of these taxa are used together with ecological preferences of the most frequent species to reconstruct the spatial and temporal distribution of the different biofacies in the past. This reveals information about Holocene palaeoenvironmental changes that are related to water depth fluctuations and the installment of the coast-parallel mud-belt. The benthic assemblage records the transition from a infralitoral environment (Biofacies I) to deeper marine condition (Biofacies III). After that the sea level reached about the modern level (Biofacies IV) the benthic foraminiferal community evidences the development of the mud-belt and the subsequent transformation of the ecological niches linked to the trophic evolution of the environment.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/30872 Collegamento a IRIS

2004 Vellaria zucchellii sp. nov. a new monothalamous foraminifer from Terra Nova Bay, Antartica.
Autore/i: Sabbatini, A; Pawlowski, J.; GOODAY A., J; Piraino, S.; Bowser, S. S.; Morigi, C.; Negri, A.
Editore: -Cambridge University Press / New York:40 West 20th Street:New York, NY 10011:(800)872-7423, (212)924-3900, EMAIL: journals_subscriptions@cup.org, INTERNET: http://www.journals.cambridge.org, Fax: (212)691-3239 -Oxford: Blackwell Scientific Publications.
Classificazione: 1 Contributo su Rivista
Abstract: Vellaria zucchellii sp. nov. is described from coastal sediment samples from Terra Nova Bay (Ross Sea, Antarctica, 74°40'28.1''S, 164°04'11.6''E, Tethys Bay, 25 m depth). This organic-walled monothalamous (single chambered) foraminifer is characterized by a wide, prominent aperture that facilitates attachment to larger particles (small sand grains or other foraminiferal shells). It shares this feature with the two other known species of Vellaria, both of which were described from an Indian estuary. Phylogenetic analysis of small subunit rRNA gene sequences suggest that V. zucchellii is related to the genus Psammophaga. However, the new species lacks the mineral grain inclusions that are characteristic of Psammophaga. The description of this new organic-walled monothalamous foraminiferal species further documents the high taxonomic diversity of these delicate and abundant protists in the polar benthic communities.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/30869 Collegamento a IRIS

2004 Abyssal benthic foraminifera in the Polar Front Region (Pacific Sector): faunal composition, standing stock and size structure.
Classificazione: 1 Contributo su Rivista
Abstract: We have evaluated the quantitative composition of Rose Bengal-stained benthic foraminiferal assemblages of surface samples from two box cores (ANTA98-28 bc; ANTA01-01 bc) collected at the Polar Front in the Pacific sector of the Southern Ocean. Size structure, faunal composition and standing stock were analysed for living (Rose Bengalstained) and dead foraminifera. The size fractions among 63-150, 150-250 and >250 μm were counted separately in order to study the foraminiferal size distribution and to compare our results with earlier Antarctic studies. The low organic carbon content of the sediment, and hence the limited food availability, is reflected by very low standing stocks and low diversity values. Calcareous taxa dominated dead foraminiferal assemblages that were more diverse than the stained assemblages. In the sediment samples of ANTA01-01 bc, the living fauna contained agglutinated taxa and soft-shelled monothalamous forms. Our data represent the southernmost record of benthic foraminiferal community (63° S) from the Polar Front region in the Pacific sector. These samples provide further evidence for the occurrence of meiofaunal foraminifera in extreme environments, like the Antarctic region, where the uncoupled annual variations in temperature and production cause strong effects on the structure of benthic communities.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/30868 Collegamento a IRIS

2004 Soft-walled, monothalamous benthic foraminiferans in the Pacific, Indian and Atlantic Oceans: Aspects of biodiversity and biogeography.
Classificazione: 1 Contributo su Rivista
Abstract: Delicate foraminiferans with test walls that are either agglutinated (Order Astrorhizida, Families Saccamminidae and Psammosphaeridae) or composed of organic material (Order Allogromiida) are often an important element of deep-sea benthic assemblages. Many species have soft, flexible walls and, except for a few allogromiids, are monothalamous (single-chambered). We examined quantitative multicorer samples from abyssal (4263–5570 m) water depths in the North and western Equatorial Pacific and a qualitative sample from a hadal site (7800 m water depth) in the Atacama Trench, SE Pacific. Soft-walled foraminiferans made up 29–42% of all complete, ‘live’ (rose Bengal stained) foraminiferans in the >32 μm fractions (0–1 cm sediment layer) of the North Pacific samples and 63% in the western Equatorial Pacific sample. They included the following morphotypes: (i) organic-walled allogromiids with one or occasionally two apertures; (ii) Nodellum- and Resigella-like forms in which the organic wall is generally brownish in colour and the test sometimes divided into more or less well-defined chambers by constrictions or partitions; (iii) flask-like agglutinated saccamminids with one aperture; (iv) oval saccamminids with two apertures; (v) agglutinated spheres which lack obvious apertures (psammosphaerids). In addition, numerous isolated spherical chambers, believed to be fragments derived from much larger komokiacean foraminiferans, were present in some samples and easily confused with saccamminids. At each Pacific station, we recognised 26–55 morphologically distinct forms (morphospecies) in addition to numerous ‘indeterminate’ specimens that could not be categorised on the basis of morphological criteria. A comparison of the Pacific assemblages with existing data on monothalamous assemblages from abyssal and bathyal depths in the Atlantic and Indian Oceans (>63 μm fraction) suggests that some morphospecies have wide geographical and bathymetric distributions. These wide-ranging morphospecies could provide good targets for future molecular-level studies addressing species differentiation among soft-shelled, monothalamous deep-sea foraminiferans.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/234544 Collegamento a IRIS

2002 Soft-shelled benthic foraminifera from a hadal site (7800 m water depth) in the Atacama Trench (SE Pacific): preliminary observations
Editore: Geological Society Publishing House:Brassmill Enterprise Centre, Unit 7, Bath Som BA1 3JN United Kingdom:011 44 1225 445046, EMAIL: dawn.angel@geolsoc.org.uk, INTERNET: http://www.geolsoc.org.uk, Fax: 011 44 1225 442836
Classificazione: 1 Contributo su Rivista
Abstract: Soft-shelled foraminifera (organic-walled allogromiids and agglutinated saccamminids) are an important component of the deep-sea meiofauna. Although these largely monothalamous taxa are common at bathyal and abyssal sites in almost all oceans, there are only two records from hadal depths. Here we report the occurence of numerous allogromiids and saccamminids in a sample collected at 7800 m water depth in the Atacama Trench. The >20 μm fraction of the core sample (0-6 cm layer) yielded a total of 546 soft-walled specimens, the vast majority of them Rose Bengal stained, belonging to 20 morphospecies. Most specimens were allogromiids (82.0%), followed by saccamminids (11.0%) and psammosphaerids (6.0%). Allogromiids, particularly Nodellum- and Resigella-like forms, were responsible for a distinct peak around 120-160 μm in the size distribution, while the spherical Allogromiid sp. 1 dominated the larger-size classes. This sample provides further evidence for the widespread occurence of soft-walled monothalamous foraminifera in marine habitats. A form resembling Resigella is common in the Atacama Trench sample but has not been observed at abyssal sites in the Pacific Ocean or Atlantic Ocean.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/30579 Collegamento a IRIS

Università Politecnica delle Marche

P.zza Roma 22, 60121 Ancona
Tel (+39) 071.220.1, Fax (+39) 071.220.2324
P.I. 00382520427