Structural and Geochemical Assessment of the Coralline Alga Tethysphytum antarcticum from Terra Nova Bay, Ross Sea, Antarctica
Crustose coralline algae (CCA) occur from the tropics to the poles in photic benthic environments. Here, we report on some of the world’s southernmost and coldest CCA sites in Terra Nova, Ross Sea, Antarctica at 74°41′ S. The recently described red alga Tethysphytum antarticum is investigated for it...
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2023
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ftdoajarticles:oai:doaj.org/article:5a9492be40f346ac912ebf5b7f60b67d 2023-05-15T14:03:42+02:00 Structural and Geochemical Assessment of the Coralline Alga Tethysphytum antarcticum from Terra Nova Bay, Ross Sea, Antarctica Matthias López Correa Sebastian Teichert Federica Ragazzola Salvador Cazorla Vázquez Felix B. Engel Katrin Hurle Claudio Mazzoli Piotr Kuklinski Giancarlo Raiteri Chiara Lombardi 2023-02-01T00:00:00Z https://doi.org/10.3390/min13020215 https://doaj.org/article/5a9492be40f346ac912ebf5b7f60b67d EN eng MDPI AG https://www.mdpi.com/2075-163X/13/2/215 https://doaj.org/toc/2075-163X doi:10.3390/min13020215 2075-163X https://doaj.org/article/5a9492be40f346ac912ebf5b7f60b67d Minerals, Vol 13, Iss 215, p 215 (2023) crustose coralline algae Antarctica taxonomy phylogeny thallus structure biomineralization Mineralogy QE351-399.2 article 2023 ftdoajarticles https://doi.org/10.3390/min13020215 2023-02-26T01:29:07Z Crustose coralline algae (CCA) occur from the tropics to the poles in photic benthic environments. Here, we report on some of the world’s southernmost and coldest CCA sites in Terra Nova, Ross Sea, Antarctica at 74°41′ S. The recently described red alga Tethysphytum antarticum is investigated for its skeletal architecture, its mineralogical and geochemical composition, as well as for its taxonomic classification. A phylogenetic analysis based on molecular genetics and the sequencing of the photosystem II protein D1 (psbA) gave a perfect match with T. antarcticum . Histological sections and micro-CT-scans provide new diagnostic details for the conceptacles (the reproductive organs of the alga). X-ray diffractometry and electron-microprobe measurements yielded a clear high-Mg calcite (~8 mol%) composition of the skeletal parts. Detailed back-scattered electron imaging of polished petrographic thin sections revealed a two-layered thallus (vegetative plant tissue), comprising an organic-rich irregularly calcified basal layer with rectangular cells, overlain by the main thallus. Elemental maps show relatively increased sulphur in the basal layer, clearly tied to organic cell walls. MgCO 3 and SrCO 3 were targeted with semiquantitative elemental mappings and in an ontogenetic quantitative spot transect. Compared with temperature (−1.95 °C to +1.08 °C), the MgCO 3 (mol%) reflects this world’s coldest CCA site temperature with the lowest MgCO 3 content of 7.9 ± 1.6 mol%. The along transect variability, however, shows with ~6 mol% a larger MgCO 3 variability than expected for the 3 °C intra-annual temperature amplitude in Terra Nova Bay. This implies that in low amplitude settings the biomineralisation control on Mg/Ca ratios can outcompete its temperature sensitivity. Mark-recapture studies, next to the environmental logger station La Zecca are suggested, to perform a detailed growth rate and biomineralisation quantification. Article in Journal/Newspaper Antarc* Antarctica antartic* Ross Sea Directory of Open Access Journals: DOAJ Articles Ross Sea Terra Nova Bay Minerals 13 2 215 |
institution |
Open Polar |
collection |
Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
crustose coralline algae Antarctica taxonomy phylogeny thallus structure biomineralization Mineralogy QE351-399.2 |
spellingShingle |
crustose coralline algae Antarctica taxonomy phylogeny thallus structure biomineralization Mineralogy QE351-399.2 Matthias López Correa Sebastian Teichert Federica Ragazzola Salvador Cazorla Vázquez Felix B. Engel Katrin Hurle Claudio Mazzoli Piotr Kuklinski Giancarlo Raiteri Chiara Lombardi Structural and Geochemical Assessment of the Coralline Alga Tethysphytum antarcticum from Terra Nova Bay, Ross Sea, Antarctica |
topic_facet |
crustose coralline algae Antarctica taxonomy phylogeny thallus structure biomineralization Mineralogy QE351-399.2 |
description |
Crustose coralline algae (CCA) occur from the tropics to the poles in photic benthic environments. Here, we report on some of the world’s southernmost and coldest CCA sites in Terra Nova, Ross Sea, Antarctica at 74°41′ S. The recently described red alga Tethysphytum antarticum is investigated for its skeletal architecture, its mineralogical and geochemical composition, as well as for its taxonomic classification. A phylogenetic analysis based on molecular genetics and the sequencing of the photosystem II protein D1 (psbA) gave a perfect match with T. antarcticum . Histological sections and micro-CT-scans provide new diagnostic details for the conceptacles (the reproductive organs of the alga). X-ray diffractometry and electron-microprobe measurements yielded a clear high-Mg calcite (~8 mol%) composition of the skeletal parts. Detailed back-scattered electron imaging of polished petrographic thin sections revealed a two-layered thallus (vegetative plant tissue), comprising an organic-rich irregularly calcified basal layer with rectangular cells, overlain by the main thallus. Elemental maps show relatively increased sulphur in the basal layer, clearly tied to organic cell walls. MgCO 3 and SrCO 3 were targeted with semiquantitative elemental mappings and in an ontogenetic quantitative spot transect. Compared with temperature (−1.95 °C to +1.08 °C), the MgCO 3 (mol%) reflects this world’s coldest CCA site temperature with the lowest MgCO 3 content of 7.9 ± 1.6 mol%. The along transect variability, however, shows with ~6 mol% a larger MgCO 3 variability than expected for the 3 °C intra-annual temperature amplitude in Terra Nova Bay. This implies that in low amplitude settings the biomineralisation control on Mg/Ca ratios can outcompete its temperature sensitivity. Mark-recapture studies, next to the environmental logger station La Zecca are suggested, to perform a detailed growth rate and biomineralisation quantification. |
format |
Article in Journal/Newspaper |
author |
Matthias López Correa Sebastian Teichert Federica Ragazzola Salvador Cazorla Vázquez Felix B. Engel Katrin Hurle Claudio Mazzoli Piotr Kuklinski Giancarlo Raiteri Chiara Lombardi |
author_facet |
Matthias López Correa Sebastian Teichert Federica Ragazzola Salvador Cazorla Vázquez Felix B. Engel Katrin Hurle Claudio Mazzoli Piotr Kuklinski Giancarlo Raiteri Chiara Lombardi |
author_sort |
Matthias López Correa |
title |
Structural and Geochemical Assessment of the Coralline Alga Tethysphytum antarcticum from Terra Nova Bay, Ross Sea, Antarctica |
title_short |
Structural and Geochemical Assessment of the Coralline Alga Tethysphytum antarcticum from Terra Nova Bay, Ross Sea, Antarctica |
title_full |
Structural and Geochemical Assessment of the Coralline Alga Tethysphytum antarcticum from Terra Nova Bay, Ross Sea, Antarctica |
title_fullStr |
Structural and Geochemical Assessment of the Coralline Alga Tethysphytum antarcticum from Terra Nova Bay, Ross Sea, Antarctica |
title_full_unstemmed |
Structural and Geochemical Assessment of the Coralline Alga Tethysphytum antarcticum from Terra Nova Bay, Ross Sea, Antarctica |
title_sort |
structural and geochemical assessment of the coralline alga tethysphytum antarcticum from terra nova bay, ross sea, antarctica |
publisher |
MDPI AG |
publishDate |
2023 |
url |
https://doi.org/10.3390/min13020215 https://doaj.org/article/5a9492be40f346ac912ebf5b7f60b67d |
geographic |
Ross Sea Terra Nova Bay |
geographic_facet |
Ross Sea Terra Nova Bay |
genre |
Antarc* Antarctica antartic* Ross Sea |
genre_facet |
Antarc* Antarctica antartic* Ross Sea |
op_source |
Minerals, Vol 13, Iss 215, p 215 (2023) |
op_relation |
https://www.mdpi.com/2075-163X/13/2/215 https://doaj.org/toc/2075-163X doi:10.3390/min13020215 2075-163X https://doaj.org/article/5a9492be40f346ac912ebf5b7f60b67d |
op_doi |
https://doi.org/10.3390/min13020215 |
container_title |
Minerals |
container_volume |
13 |
container_issue |
2 |
container_start_page |
215 |
_version_ |
1766274506795515904 |