@article {bendif_rapid_2023,
	title = {Rapid diversification underlying the global dominance of a cosmopolitan phytoplankton},
	journal = {The ISME Journal},
	year = {2023},
	note = {Publisher: Nature Publishing Group},
	pages = {1{\textendash}11},
	abstract = {Marine phytoplankton play important roles in the global ecosystem, with a limited number of cosmopolitan keystone species driving their biomass. Recent studies have revealed that many of these phytoplankton are complexes composed of sibling species, but little is known about the evolutionary processes underlying their formation. Gephyrocapsa huxleyi, a widely distributed and abundant unicellular marine planktonic algae, produces calcified scales (coccoliths), thereby significantly affects global biogeochemical cycles via sequestration of inorganic carbon. This species is composed of morphotypes defined by differing degrees of coccolith calcification, the evolutionary ecology of which remains unclear. Here, we report an integrated morphological, ecological and genomic survey across globally distributed G. huxleyi strains to reconstruct evolutionary relationships between morphotypes in relation to their habitats. While G. huxleyi has been considered a single cosmopolitan species, our analyses demonstrate that it has evolved to comprise at least three distinct species, which led us to formally revise the taxonomy of the G. huxleyi complex. Moreover, the first speciation event occurred before the onset of the last interglacial period (\textasciitilde140 ka), while the second followed during this interglacial. Then, further rapid diversifications occurred during the most recent ice-sheet expansion of the last glacial period and established morphotypes as dominant populations across environmental clines. These results suggest that glacial-cycle dynamics contributed to the isolation of ocean basins and the segregations of oceans fronts as extrinsic drivers of micro-evolutionary radiations in extant marine phytoplankton.},
	keywords = {Microbial biooceanography, phylogenomics, population genetics, rcc1212, RCC1216, rcc1220, RCC1239, RCC1240, RCC1242, RCC1245, rcc1252, RCC1253, RCC1266, RCC1304, rcc1731, RCC1754, RCC1813, RCC1823, rcc1824, RCC1830, RCC1838, RCC1840, RCC1853, RCC1856, RCC3746, RCC4027, RCC4028, RCC4030, RCC5134, RCC5137, RCC5141, RCC6381, RCC6421, RCC6427, RCC6566, RCC6660, RCC6666, RCC911, RCC963},
	issn = {1751-7370},
	doi = {10.1038/s41396-023-01365-5},
	url = {https://www.nature.com/articles/s41396-023-01365-5},
	author = {Bendif, El Mahdi and Probert, Ian and Archontikis, Odysseas A. and Young, Jeremy R. and Beaufort, Luc and Rickaby, Rosalind E. and Filatov, Dmitry}
}
@article {gebuhr_strain-specific_2021,
	title = {Strain-specific morphological response of the dominant calcifying phytoplankton species Emiliania huxleyi to salinity change},
	journal = {PLOS ONE},
	volume = {16},
	number = {2},
	year = {2021},
	note = {Publisher: Public Library of Science},
	month = {feb},
	pages = {e0246745},
	abstract = {The future physiology of marine phytoplankton will be impacted by a range of changes in global ocean conditions, including salinity regimes that vary spatially and on a range of short- to geological timescales. Coccolithophores have global ecological and biogeochemical significance as the most important calcifying marine phytoplankton group. Previous research has shown that the morphology of their exoskeletal calcified plates (coccoliths) responds to changing salinity in the most abundant coccolithophore species, Emiliania huxleyi. However, the extent to which these responses may be strain-specific is not well established. Here we investigated the growth response of six strains of E. huxleyi under low (ca. 25) and high (ca. 45) salinity batch culture conditions and found substantial variability in the magnitude and direction of response to salinity change across strains. Growth rates declined under low and high salinity conditions in four of the six strains but increased under both low and high salinity in strain RCC1232 and were higher under low salinity and lower under high salinity in strain PLYB11. When detailed changes in coccolith and coccosphere size were quantified in two of these strains that were isolated from contrasting salinity regimes (coastal Norwegian low salinity of ca. 30 and Mediterranean high salinity of ca. 37), the Norwegian strain showed an average 26\% larger mean coccolith size at high salinities compared to low salinities. In contrast, coccolith size in the Mediterranean strain showed a smaller size trend (11\% increase) but severely impeded coccolith formation in the low salinity treatment. Coccosphere size similarly increased with salinity in the Norwegian strain but this trend was not observed in the Mediterranean strain. Coccolith size changes with salinity compiled for other strains also show variability, strongly suggesting that the effect of salinity change on coccolithophore morphology is likely to be strain specific. We propose that physiological adaptation to local conditions, in particular strategies for plasticity under stress, has an important role in determining ecotype responses to salinity.},
	keywords = {Calcification, Carbonates, Ecophysiology, Marine ecology, Marine geology, Morphometry, Paleoclimatology, rcc1210, RCC1232, rcc1824, rcc868, RCC904, salinity},
	issn = {1932-6203},
	doi = {10.1371/journal.pone.0246745},
	url = {https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0246745},
	author = {Geb{\"u}hr, Christina and Sheward, Rosie M. and Herrle, Jens O. and Bollmann, J{\"o}rg}
}
@article {LingeJohnsen2019,
	title = {Relationship between coccolith length and thickness in the coccolithophore species Emiliania huxleyi and Gephyrocapsa oceanica},
	journal = {PLOS ONE},
	volume = {14},
	number = {8},
	year = {2019},
	note = {tex.mendeley-tags: RCC1210,RCC1223,RCC1232,RCC1824,RCC1843,RCC868},
	month = {aug},
	pages = {e0220725},
	keywords = {rcc1210, RCC1223, RCC1232, rcc1824, rcc1843, rcc868},
	issn = {1932-6203},
	doi = {10.1371/journal.pone.0220725},
	url = {http://dx.plos.org/10.1371/journal.pone.0220725},
	author = {Linge Johnsen, Simen Alexander and Bollmann, J{\"o}rg and Gebuehr, Christina and Herrle, Jens O.},
	editor = {Keller, David Peter}
}
