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  • 1001.
    Zhang, Zhiliang
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Geovetenskapliga sektionen, Institutionen för geovetenskaper, Paleobiologi. Northwest Univ, Early Life Inst, State Key Lab Continental Dynam, Xian 710069, Peoples R China.
    Zhang, Zhifei
    Northwest Univ, Early Life Inst, State Key Lab Continental Dynam, Xian 710069, Peoples R China..
    Wang, Haizhou
    China Univ Petr, Dept Geol, Beijing 102249, Peoples R China..
    Epithelial cell moulds preserved in the earliest acrotretid brachiopods from the Cambrian (Series 2) of the Three Gorges area, China2016Ingår i: GFF, ISSN 1103-5897, E-ISSN 2000-0863, Vol. 138, nr 4, s. 455-466Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Distinctive moulds of epithelial cells are known to occur on valve interiors in early Palaeozoic acrotretid brachiopods but morphological variation and distributional patterns of the epithelial cells imprints remains poorly known. Herein, we present for the first time a detailed study of exquisitely preserved epithelial cell moulds and shell micro-structures in acid-etched material of the earliest acrotretid brachiopod Eohadrotreta zhenbaensis from the Shuijingtuo Formation (Cambrian Series 2) of Aijiahe section, approximately 25km north-west of Yichang City, western Hubei Province. The ventral and dorsal epithelial cell moulds (on average 18m across) are usually isometrically convex or concave polygonal with a variable outline (tetragon, pentagon and hexagon). Investigation of the new material demonstrates that the disposition of pronounced epithelial cell pustules or depressions in shell interiors most likely is associated with regions of thickened muscle attachments in ventral and dorsal valves - a character that potentially could be of use in taxonomy, though detailed comparative studies of such epithelial microstructures of acrotretids and other brachiopod taxa remain to be done.

  • 1002.
    Zigaite, Zivile
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för organismbiologi, Evolution och utvecklingsbiologi.
    Kear, Benjamin
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Geovetenskapliga sektionen, Institutionen för geovetenskaper, Paleobiologi.
    Joachimski, Michael M.
    University of Erlangen-Nuremberg.
    Tutken, Thomas
    University of Bonn.
    Whitehouse, Martin
    Naturhistoriska Riksmuseet.
    Blom, Henning
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för organismbiologi, Evolution och utvecklingsbiologi.
    Geochemistry of dental bioapatite, the key to palaeoclimate2013Ingår i: Proceedings of the 3rd IGCP 591 Annual Meeting, Lund, Sweden, 9-19 June 2013 / [ed] Anders Lindskog and Kristina Mehlqvist, Lund: Department of Geology, Lund University , 2013, s. 361-362Konferensbidrag (Refereegranskat)
  • 1003.
    Zigaite, Zivile
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för organismbiologi, Evolution och utvecklingsbiologi.
    Kear, Benjamin
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Geovetenskapliga sektionen, Institutionen för geovetenskaper, Paleobiologi.
    Perez-Huerta, Alberto
    University of Alabama.
    Jeffries, Teresa
    Natural History Museum.
    Do fossil vertebrate biominerals hold the key to Palaeozoic climate?2012Konferensbidrag (Refereegranskat)
    Abstract [en]

    Fossil vertebrate hard tissues - teeth and dermoskeleton - are considered among the most geochemically stable biominerals, and therefore are widely used for palaeoenvironmental and palaeoclimatic reconstructions. Elemental and isotopic compositions of fossil dental tissues may provide unique palaeoenvironmental information, ranging from the diet and trophic positions on a food chain, to the palaeosalinity and water temperatures of ancient seas. However, before starting any geochemical interpretations, the preservation potential of fossil tissues must be studied carefully, considering possible alteration of the primary geochemical composition. Evaluation of fossil hard tissue preservation can be made by semiquantitative spot geochemistry analyses on fine polished teeth and scale thin sections using Energy Dispersive X-ray Spectroscopy (EDS), and help to roughly preview the chemical composition. The Electron Backscatter Diffractometry (EBSD) is useful to examine the cristallinity and possible structural alterations. In addition, rare earth element (REE) abundances can be measured in situ within the fine fossil tissues (such as enamel vs. dentine) using Laser Ablation Inductively Coupled Plasma Mass-spectrometry (LA-ICP-MS), and give us information about the selective geochemical resilience between separate vertebrate hard tissues. To conclude, in order to decipher the geochemical signal of fossil biominerals correctly, the evaluation of preservation should be the starting point to any further geochemical studies.

  • 1004.
    Zigaite, Zivile
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för organismbiologi, Evolution och utvecklingsbiologi.
    Perez-Huerta, Alberto
    University of Alabama.
    Jeffries, Teresa
    Natural History Museum.
    Kear, Benjamin P
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Geovetenskapliga sektionen, Institutionen för geovetenskaper, Paleobiologi.
    Blom, Henning
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för organismbiologi, Evolution och utvecklingsbiologi.
    Geochemistry of fossilised dental remains - key to palaeobiology and palaeoenvironment.2013Ingår i: GFF, ISSN 1103-5897, E-ISSN 2000-0863, Vol. 135, nr 1, s. 25-Artikel i tidskrift (Refereegranskat)
  • 1005. Zuykov, M. A.
    et al.
    Egerquist, Eva
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Geovetenskapliga sektionen, Institutionen för geovetenskaper. Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Geovetenskapliga sektionen, Institutionen för geovetenskaper, Paleobiologi. Palaeobiology.
    The Upper Ordovician and lower Silurian Platystrophia-like brachiopods from Sweden2004Konferensbidrag (Övrigt vetenskapligt)
  • 1006. Zykov, Michael A.
    et al.
    Egerquist, Eva
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Geovetenskapliga sektionen, Institutionen för geovetenskaper. Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Geovetenskapliga sektionen, Institutionen för geovetenskaper, Paleobiologi.
    A new Platystrophia-like brachiopod genus from the Ordovician Boda Limestone of Dalarna, Sweden2005Ingår i: GFF, Vol. 127, nr 1, s. 1-5Artikel i tidskrift (Refereegranskat)
  • 1007.
    Šupraha, Luka
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Geovetenskapliga sektionen, Institutionen för geovetenskaper, Paleobiologi.
    Phenotypic evolution and adaptive strategies in marine phytoplankton (Coccolithophores)2016Doktorsavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [en]

    Coccolithophores are biogeochemically important marine algae that interact with the carbon cycle through photosynthesis (CO2 sink), calcification (CO2 source) and burial of carbon into oceanic sediments. The group is considered susceptible to the ongoing climate perturbations, in particular to ocean acidification, temperature increase and nutrient limitation. The aim of this thesis was to investigate the adaptation of coccolithophores to environmental change, with the focus on temperature stress and nutrient limitation. The research was conducted in frame of three approaches: experiments testing the physiological response of coccolithophore species Helicosphaera carteri and Coccolithus pelagicus to phosphorus limitation, field studies on coccolithophore life-cycles with a method comparison and an investigation of the phenotypic evolution of the coccolithophore genus Helicosphaera over the past 15 Ma. Experimental results show that the physiology and morphology of large coccolithophores are sensitive to phosphorus limitation, and that the adaptation to low-nutrient conditions can lead to a decrease in calcification rates. Field studies have contributed to our understanding of coccolithophore life cycles, revealing complex ecological patterns within the Mediterranean community which are seemingly regulated by seasonal, temperature-driven environment changes. In addition, the high-throughput sequencing (HTS) molecular method was shown to provide overall good representation of coccolithophore community composition. Finally, the study on Helicosphaera evolution showed that adaptation to decreasing CO2 in higher latitudes involved cell and coccolith size decrease, whereas the adaptation in tropical ecosystems also included a physiological decrease in calcification rates in response to nutrient limitation. This thesis advanced our understanding of coccolithophore adaptive strategies and will improve our predictions on the fate of the group under ongoing climate change.

    Delarbeten
    1. Eco-physiological adaptation shapes the response of calcifying algae to nutrient limitation
    Öppna denna publikation i ny flik eller fönster >>Eco-physiological adaptation shapes the response of calcifying algae to nutrient limitation
    2015 (Engelska)Ingår i: Scientific Reports, ISSN 2045-2322, E-ISSN 2045-2322, Vol. 5, artikel-id 16499Artikel i tidskrift (Refereegranskat) Published
    Abstract [en]

    The steady increase in global ocean temperature will most likely lead to nutrient limitation in the photic zone. This will impact the physiology of marine algae, including the globally important calcifying coccolithophores. Understanding their adaptive patterns is essential for modelling carbon production in a low-nutrient ocean. We investigated the physiology of Helicosphaera carteri, a representative of the abundant but under-investigated flagellated functional group of coccolithophores. Two strains isolated from contrasting nutrient regimes (South Atlantic and Mediterranean Sea) were grown in phosphorus-replete and phosphorus-limited batch cultures. While growing exponentially in a phosphorus-replete medium, the Mediterranean strain exhibited on average 24% lower growth rate, 36% larger coccosphere volume and 21% lower particulate inorganic carbon (PIC) production than the Atlantic strain. Under phosphorus limitation, the same strain was capable of reaching a 2.6 times higher cell density than the Atlantic strain due to lower phosphorus requirements. These results suggest that local physiological adaptation can define the performance of this species under nutrient limitation.

    Nationell ämneskategori
    Ekologi Cellbiologi Evolutionsbiologi Geovetenskap och miljövetenskap
    Identifikatorer
    urn:nbn:se:uu:diva-253354 (URN)10.1038/srep16499 (DOI)000364487200001 ()26560531 (PubMedID)
    Forskningsfinansiär
    Knut och Alice Wallenbergs StiftelseKungliga Vetenskapsakademien
    Tillgänglig från: 2015-05-26 Skapad: 2015-05-26 Senast uppdaterad: 2017-12-04Bibliografiskt granskad
    2. High temperature decreases the PIC/POC ratio and increases phosphorus requirements in Coccolithus pelagicus (Haptophyta)
    Öppna denna publikation i ny flik eller fönster >>High temperature decreases the PIC/POC ratio and increases phosphorus requirements in Coccolithus pelagicus (Haptophyta)
    Visa övriga...
    2014 (Engelska)Ingår i: Biogeosciences, ISSN 1726-4170, E-ISSN 1726-4189, Vol. 11, s. 3531-3545Artikel i tidskrift (Refereegranskat) Published
    Abstract [en]

    Rising ocean temperatures will likely increase stratification of the water column and reduce nutrient input into the photic zone. This will increase the likelihood of nutrient limitation in marine microalgae, leading to changes in the abundance and composition of phytoplankton communities, which in turn will affect global biogeochemical cycles. Calcifying algae, such as coccolithophores, influence the carbon cycle by fixing CO2 into particulate organic carbon through photosynthesis (POC production) and into particulate inorganic carbon through calcification (PIC production). As calcification produces a net release of CO2, the ratio of PIC to POC production determines whether coccolithophores act as a source (high PIC / POC) or a sink (low PIC / POC) of atmospheric CO2. We studied the effect of phosphorus (P-) limitation and high temperature on the physiology and the PIC / POC ratio of two subspecies of Coccolithus pelagicus. This large and heavily calcified species is a major contributor to calcite export from the photic zone into deep-sea reservoirs. Phosphorus limitation did not influence exponential growth rates in either subspecies, but P-limited cells had significantly lower cellular P-content. One of the subspecies was subjected to a 5 °C temperature increase from 10 °C to 15 °C, which did not affect exponential growth rates either, but nearly doubled cellular P-content under both high and low phosphate availability. This temperature increase reduced the PIC / POC ratio by 40–60%, whereas the PIC / POC ratio did not differ between P-limited and nutrient-replete cultures when the subspecies were grown near their respective isolation temperature. Both P-limitation and elevated temperature significantly increased coccolith malformations. Our results suggest that a temperature increase may intensify P-limitation due to a higher P-requirement to maintain growth and POC production rates, possibly reducing abundances in a warmer ocean. Under such a scenario C. pelagicus may decrease its calcification rate relative to photosynthesis, thus favouring CO2 sequestration over release. It seems unlikely that P-limitation by itself causes changes in the PIC / POC ratio in this species.

    Nyckelord
    coccolithophores, culture experiments, phosphate limitation, calcification
    Nationell ämneskategori
    Naturvetenskap
    Forskningsämne
    Biologi; Geovetenskap med inriktning mot miljöanalys
    Identifikatorer
    urn:nbn:se:uu:diva-220830 (URN)10.5194/bg-11-3531-2014 (DOI)000339265800008 ()
    Tillgänglig från: 2014-03-20 Skapad: 2014-03-20 Senast uppdaterad: 2017-12-05Bibliografiskt granskad
    3. Phosphorus availability modifies carbon production in Coccolithus pelagicus (Haptophyta)
    Öppna denna publikation i ny flik eller fönster >>Phosphorus availability modifies carbon production in Coccolithus pelagicus (Haptophyta)
    Visa övriga...
    2015 (Engelska)Ingår i: Journal of Experimental Marine Biology and Ecology, ISSN 0022-0981, E-ISSN 1879-1697, Vol. 472, s. 24-31Artikel i tidskrift (Refereegranskat) Published
    Abstract [en]

    Abstract The coccolithophore Coccolithus pelagicus (Wallich) Schiller fixes CO2 into particulate organic carbon (POC) through photosynthesis and into particulate inorganic carbon (PIC) in the form of calcite. To examine the role of phosphorus (P) availability in the production of POC and PIC, C. pelagicus subsp. braarudii (Gaarder) Geisen et al. was grown in semi-continuous cultures at three initial phosphate concentrations (P-replete, 1, and 0.5 μM [P]). Reduced P-availability (1 and 0.5 μM [P]) decreased POC production, while PIC production only decreased when phosphate concentrations became growth limiting (0.5 μM [P]). This decrease has not been observed previously in batch cultures, highlighting the inadequacy of the batch culture approach with regard to determining carbon production. The reduction in growth rate by 50% at 0.5 μM [P] was accompanied by a doubling in cell volume (and POC). PIC production was halved, resulting in a lowered PIC to POC ratio. The average number of coccoliths per cell (and PIC content) remained the same among treatments, despite the significant change in cell size. Our data suggest that POC production in C. pelagicus is more sensitive towards a moderate reduction in phosphorus availability than PIC production. Once phosphorus availability limits cell division, however, phosphorus resources are invested into POC rather than PIC production. This reduces cell density and sinking rates, indicating that coccoliths do not act as ballast for reaching deeper nutrient-rich layers under nutrient limitation.

    Nyckelord
    Calcification, Carbon production, Coccolithus pelagicus, Phosphorus limitation, Semi-continuous culture
    Nationell ämneskategori
    Mikrobiologi Cellbiologi
    Identifikatorer
    urn:nbn:se:uu:diva-301334 (URN)
    Tillgänglig från: 2016-08-19 Skapad: 2016-08-19 Senast uppdaterad: 2017-11-28
    4. Observations on the life cycle and ecology of Acanthoica quattrospina Lohmann from a Mediterranean estuary
    Öppna denna publikation i ny flik eller fönster >>Observations on the life cycle and ecology of Acanthoica quattrospina Lohmann from a Mediterranean estuary
    2014 (Engelska)Ingår i: Journal of Nannoplankton Research, ISSN 1210-8049, Vol. 34, nr SI, s. 49-56Artikel i tidskrift (Refereegranskat) Published
    Nationell ämneskategori
    Ekologi Biologisk systematik
    Identifikatorer
    urn:nbn:se:uu:diva-253353 (URN)
    Konferens
    INA Workshop on Extant Coccolithophores research
    Tillgänglig från: 2015-05-26 Skapad: 2015-05-26 Senast uppdaterad: 2016-09-13Bibliografiskt granskad
    5. Coccolithophore life-cycle dynamics in a coastal Mediterranean ecosystem: seasonality and species-specific patterns
    Öppna denna publikation i ny flik eller fönster >>Coccolithophore life-cycle dynamics in a coastal Mediterranean ecosystem: seasonality and species-specific patterns
    2016 (Engelska)Ingår i: Journal of Plankton Research, ISSN 0142-7873, E-ISSN 1464-3774, Vol. 38, nr 5, s. 1178-1193Artikel i tidskrift (Refereegranskat) Published
    Abstract [en]

    Coccolithophores (calcifying haptophyte algae) commonly exhibit a heteromorphic life cycle, alternating between morphologically distinct heterococcolith (diploid) and holococcolith (haploid) phases. The prevalence of each life phase in a coccolithophore community defines its overall ecological and biogeochemical performance due to differences in physiology, biomass and calcification. The main drivers of life-cycle dynamics and ecological preferences of the two life-phases are still unclear and field data of high taxonomic resolution are needed. We investigated the distribution and abundance patterns of the life-phases of 14 coccolithophore species. The study was conducted along the strong environmental gradients of the Krka River estuary (Eastern Adriatic Sea) during winter (February) and summer (July) 2013. The results reveal characteristic life-phase seasonality with an overall dominance of the heterococcolith phase during winter and a holococcolith phase during summer. However, we also detected exceptions to the strictly seasonal patterns as well as species-specific ecological preferences. Our findings provide new insights into coccolithophore life-phase dynamics in the Mediterranean Sea that will further advance the understanding of ecology and evolution of the group.

    Nationell ämneskategori
    Geovetenskap och miljövetenskap Biologiska vetenskaper
    Identifikatorer
    urn:nbn:se:uu:diva-302897 (URN)10.1093/plankt/fbw061 (DOI)000384135000004 ()
    Tillgänglig från: 2016-09-12 Skapad: 2016-09-12 Senast uppdaterad: 2019-01-25Bibliografiskt granskad
    6. Haptophyte diversity and vertical distribution explored by 18S and 28S ribosomal RNA gene metabarcoding and scanning electron microscopy
    Öppna denna publikation i ny flik eller fönster >>Haptophyte diversity and vertical distribution explored by 18S and 28S ribosomal RNA gene metabarcoding and scanning electron microscopy
    2017 (Engelska)Ingår i: Journal of Eukaryotic Microbiology, ISSN 1066-5234, E-ISSN 1550-7408, Vol. 64, nr 4, s. 514-532Artikel i tidskrift (Refereegranskat) Published
    Abstract [en]

    Haptophyta encompasses more than 300 species of mostly marine pico- and nanoplanktonic flagellates. Our aims were to investigate the Oslofjorden haptophyte diversity and vertical distribution by metabarcoding, and to improve the approach to study haptophyte community composition, richness and proportional abundance by comparing two rRNA markers and scanning electron microscopy (SEM). Samples were collected in August 2013 at the Outer Oslofjorden, Norway. Total RNA/cDNA was amplified by haptophyte-specific primers targeting the V4 region of the 18S, and the D1-D2 region of the 28S rRNA. Taxonomy was assigned using curated haptophyte reference databases and phylogenetic analyses. Both marker genes showed Chrysochromulinaceae and Prymnesiaceae to be the families with highest number of Operational Taxonomic Units (OTUs), as well as proportional abundance. The 18S rRNA data setalso contained OTUs assigned to eight supported and defined clades consisting of environmental sequences only, possibly representing novel lineages from family to class. We also recorded new species for the area. Comparing coccolithophores by SEM with metabarcoding shows a good correspondence with the 18S rRNA gene proportional abundances. Our results contribute to link morphological and molecular data and 28S to 18S rRNA gene sequences of haptophytes without cultured representatives, and to improve metabarcoding methodology.

    Nyckelord
    Abundance, coccolithophores, high-throughput sequencing, Oslofjorden, phylogeny, richness
    Nationell ämneskategori
    Biologiska vetenskaper Biologisk systematik Biokemi och molekylärbiologi
    Identifikatorer
    urn:nbn:se:uu:diva-302898 (URN)10.1111/jeu.12388 (DOI)000406102000010 ()27973742 (PubMedID)
    Anmärkning

    De två första författarna delar förstaförfattarskapet.

    Tillgänglig från: 2016-09-12 Skapad: 2016-09-12 Senast uppdaterad: 2017-11-02Bibliografiskt granskad
    7. Nutrient availability modified the evolution of calcifying algae during the past 15 million years
    Öppna denna publikation i ny flik eller fönster >>Nutrient availability modified the evolution of calcifying algae during the past 15 million years
    (Engelska)Manuskript (preprint) (Övrigt vetenskapligt)
    Nationell ämneskategori
    Evolutionsbiologi Geovetenskap och miljövetenskap
    Identifikatorer
    urn:nbn:se:uu:diva-302900 (URN)
    Externt samarbete:
    Tillgänglig från: 2016-09-12 Skapad: 2016-09-12 Senast uppdaterad: 2016-09-13
  • 1008.
    Šupraha, Luka
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Geovetenskapliga sektionen, Institutionen för geovetenskaper, Paleobiologi.
    Bosak, Sunčica
    Ljubešić, Zrinka
    Mihanović, Hrvoje
    Olujić, Goran
    Mikac, Iva
    Viličić, Damir
    Cryptophyte bloom in a Mediterranean estuary: High abundance of Plagioselmis cf. prolonga in the Krka River estuary (eastern Adriatic Sea)2014Ingår i: Scientia Marina, ISSN 0214-8358, E-ISSN 1886-8134, Vol. 78, nr 3, s. 329-338Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    During the June 2010 survey of phytoplankton and physicochemical parameters in the Krka River estuary (eastern Adriatic Sea), a cryptophyte bloom was observed. High abundance of cryptophytes (maximum 7.9x10(6) cells l(-1)) and high concentrations of the class-specific biomarker pigment alloxanthine (maximum 2312 ng l(-1)) were detected in the surface layer and at the halocline in the lower reach of the estuary. Taxonomical analysis revealed that the blooming species was Plagioselmis cf. prolonga. Analysis of the environmental parameters in the estuary suggested that the bloom was supported by the slower river flow as well as the increased orthophosphate and ammonium concentrations. The first record of a cryptophyte bloom in the Krka River estuary may indicate that large-scale changes are taking place in the phytoplankton community. Such changes could have a major impact on the natural ecosystem dynamics and the mariculture production in the area.

  • 1009.
    Šupraha, Luka
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Geovetenskapliga sektionen, Institutionen för geovetenskaper, Paleobiologi.
    Bosak, Sunčica
    Ljubešić, Zrinka
    Olujić, Goran
    Horvat, Lucija
    Viličić, Damir
    The phytoplankton composition and spatial distribution in the north-eastern Adriatic Channel in autumn 20082011Ingår i: Acta Adriatica, ISSN 0001-5113, E-ISSN 1846-0453, Vol. 52, nr 1Artikel i tidskrift (Refereegranskat)
  • 1010.
    Šupraha, Luka
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Geovetenskapliga sektionen, Institutionen för geovetenskaper, Paleobiologi.
    Gerecht, Andrea C.
    Probert, Ian
    Henderiks, Jorijntje
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Geovetenskapliga sektionen, Institutionen för geovetenskaper, Paleobiologi.
    The adaptive strategies of coccolithophores and their biogeochemical implications2016Konferensbidrag (Refereegranskat)
  • 1011.
    Šupraha, Luka
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Geovetenskapliga sektionen, Institutionen för geovetenskaper, Paleobiologi.
    Gerecht, Andrea Cornelia
    Probert, Ian
    Henderiks, Jorijntje
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Geovetenskapliga sektionen, Institutionen för geovetenskaper, Paleobiologi.
    Eco-physiological adaptation shapes the response of calcifying algae to nutrient limitation2015Ingår i: Scientific Reports, ISSN 2045-2322, E-ISSN 2045-2322, Vol. 5, artikel-id 16499Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The steady increase in global ocean temperature will most likely lead to nutrient limitation in the photic zone. This will impact the physiology of marine algae, including the globally important calcifying coccolithophores. Understanding their adaptive patterns is essential for modelling carbon production in a low-nutrient ocean. We investigated the physiology of Helicosphaera carteri, a representative of the abundant but under-investigated flagellated functional group of coccolithophores. Two strains isolated from contrasting nutrient regimes (South Atlantic and Mediterranean Sea) were grown in phosphorus-replete and phosphorus-limited batch cultures. While growing exponentially in a phosphorus-replete medium, the Mediterranean strain exhibited on average 24% lower growth rate, 36% larger coccosphere volume and 21% lower particulate inorganic carbon (PIC) production than the Atlantic strain. Under phosphorus limitation, the same strain was capable of reaching a 2.6 times higher cell density than the Atlantic strain due to lower phosphorus requirements. These results suggest that local physiological adaptation can define the performance of this species under nutrient limitation.

  • 1012.
    Šupraha, Luka
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Geovetenskapliga sektionen, Institutionen för geovetenskaper, Paleobiologi.
    Gerecht, Andrea
    Edvardsen, Bente
    Henderiks, Jorijntje
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Geovetenskapliga sektionen, Institutionen för geovetenskaper, Paleobiologi.
    Is phosphate availability significant to the morphological diversity within Helicosphaera carteri?2013Konferensbidrag (Övrigt vetenskapligt)
  • 1013.
    Šupraha, Luka
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Geovetenskapliga sektionen, Institutionen för geovetenskaper, Paleobiologi.
    Gerecht, Andrea
    Probert, Ian
    Henderiks, Jorijntje
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Geovetenskapliga sektionen, Institutionen för geovetenskaper, Paleobiologi.
    Strain-specific ecophysiological traits define the response to phosphorus limitation in Helicosphaera carteri2015Konferensbidrag (Övrigt vetenskapligt)
  • 1014.
    Šupraha, Luka
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Geovetenskapliga sektionen, Institutionen för geovetenskaper, Paleobiologi.
    Henderiks, Jorijntje
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Geovetenskapliga sektionen, Institutionen för geovetenskaper, Paleobiologi.
    Nutrient availability modified the evolution of calcifying algae during the past 15 million yearsManuskript (preprint) (Övrigt vetenskapligt)
  • 1015.
    Šupraha, Luka
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Geovetenskapliga sektionen, Institutionen för geovetenskaper, Paleobiologi.
    Ljubešić, Zrinka
    Henderiks, Jorijntje
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Geovetenskapliga sektionen, Institutionen för geovetenskaper, Paleobiologi.
    Combination coccospheres from the eastern Adriatic coast (Mediterranean Sea)2015Konferensbidrag (Övrigt vetenskapligt)
  • 1016.
    Šupraha, Luka
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Geovetenskapliga sektionen, Institutionen för geovetenskaper, Paleobiologi.
    Ljubešić, Zrinka
    Univ Zagreb, Fac Sci, Dept Biol, Rooseveltov Trg 6, Zagreb 10000, Croatia.
    Mihanović, Hrvoje
    Inst Oceanog & Fisheries, Setaliste Ivana Mestrov 63, Split 21000, Croatia.
    Henderiks, Jorijntje
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Geovetenskapliga sektionen, Institutionen för geovetenskaper, Paleobiologi. Inst Oceanog & Fisheries, Setaliste Ivana Mestrov 63, Split 21000, Croatia [Show the Organization-Enhanced name(s)] [ 4 ] Univ Oslo, Dept Biosci, CEES, POB 1066 Blindern, N-0316 Oslo, Norway.
    Coccolithophore life-cycle dynamics in a coastal Mediterranean ecosystem: seasonality and species-specific patterns2016Ingår i: Journal of Plankton Research, ISSN 0142-7873, E-ISSN 1464-3774, Vol. 38, nr 5, s. 1178-1193Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Coccolithophores (calcifying haptophyte algae) commonly exhibit a heteromorphic life cycle, alternating between morphologically distinct heterococcolith (diploid) and holococcolith (haploid) phases. The prevalence of each life phase in a coccolithophore community defines its overall ecological and biogeochemical performance due to differences in physiology, biomass and calcification. The main drivers of life-cycle dynamics and ecological preferences of the two life-phases are still unclear and field data of high taxonomic resolution are needed. We investigated the distribution and abundance patterns of the life-phases of 14 coccolithophore species. The study was conducted along the strong environmental gradients of the Krka River estuary (Eastern Adriatic Sea) during winter (February) and summer (July) 2013. The results reveal characteristic life-phase seasonality with an overall dominance of the heterococcolith phase during winter and a holococcolith phase during summer. However, we also detected exceptions to the strictly seasonal patterns as well as species-specific ecological preferences. Our findings provide new insights into coccolithophore life-phase dynamics in the Mediterranean Sea that will further advance the understanding of ecology and evolution of the group.

  • 1017.
    Žigaitė, Živilė
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för organismbiologi, Evolution och utvecklingsbiologi.
    Pérez-Huerta, Alberto
    University of Alabama, USA.
    Jeffries, Teresa
    Natural History Museum, London, UK.
    Kear, Benjamin
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Geovetenskapliga sektionen, Institutionen för geovetenskaper, Paleobiologi.
    Blom, Henning
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för organismbiologi, Evolution och utvecklingsbiologi.
    REE compositions in fossil vertebrate dental tissues – key to biomineral preservation2011Ingår i: The Palaeontological Association Newsletter, 2011Konferensbidrag (Övrigt vetenskapligt)
    Abstract [en]

    Rare earth element (REE) abundances have been measured in a number of Palaeozoic and Mesozoic vertebrate hard tissues (teeth and dermoskeleton) using laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS). Fossil vertebrate analysed comprise scales and tesserae of Silurian and Devonian thelodonts, chondrichthyans, galeaspids, mongolepids, spines of acanthodians, as well as teeth of Cretaceous lungfish and marine reptiles.

    Pre-evaluation of fossil preservation level has been made by semi-quantitative spot geochemistry analyses on fine polished teeth and scale thin sections, using energy dispersive X-ray spectroscopy (EDS). Silicification of bioapatite, together with elevated heavy element concentrations corresponded to fossil tissue structure and colour alteration. Stable oxygen isotope measurements (δ<sup>18</sup>O) of bulk biomineral have been conducted in parallel, generally yielding lower heavy oxygen values in stronger alterated teeth and scales. Clear distinction in REE concentrations was observed between dentine and enamel of Cretaceous plesiosaurs, suggesting enamel to be more geochemically resistant to diagenetic overprint.

  • 1018.
    Žigaitė, Živilė
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för organismbiologi, Evolution och utvecklingsbiologi.
    Pérez-Huerta, Alberto
    Department of Geological Sciences, University of Alabama.
    Jeffries, Teresa
    Mineralogy Department, Natural History Museum, London.
    Kear, Benjamin P
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Geovetenskapliga sektionen, Institutionen för geovetenskaper, Paleobiologi.
    Blom, Henning
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för organismbiologi, Evolution och utvecklingsbiologi.
    Geochemistry of fossilised dental remains: a key to palaeobiology and palaeoenvironment2011Ingår i: Abstracts: The 2nd Wiman meeting : Carl Wiman's Legacy: 100 years of Swedish Palaeontology : Uppsala 17–18 November 2011 / [ed] Benjamin P. Kear, Michael Streng, 2011, s. 24-25Konferensbidrag (Övrigt vetenskapligt)
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