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Papposphaera heldalii sp. nov. (Haptophyta, Papposphaeraceae) from Svalbard

100%
Thomsen H. A., Egge J. K.
Acta Protozoologica
|
2016
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vol. 55
|
issue 1
PL
In an attempt to establish a taxonomy for the polar contingent of lightly calcified coccolithophores, we are currently dealing with species of Papposphaera. Here we describe a new species, Papposphaera heldalii sp. nov., based on material from Svalbard. The species is unique in terms of calyx design, which is an elegant modification of the standard P. sagittifera theme, and also in terms of the absence of central area calcification in body coccoliths. The species thus occupies a further step in a sequence of five Arctic forms ranging from P. sagittifera via P. sarion, P. arctica and P. iugifera to P. heldalii showing a gradual reduction of central area calcification in body coccoliths. P. heldalii is unique also in the sense that the species has not been found during any of the major Arctic TEM nanoplankton surveys conducted during the last decades.
2
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Coccolithophores in Polar Waters: Papposphaera sagittifera HET and HOL Revisited

81%
Thomsen H. A., Østergaard J. B., HELDAL M.
Acta Protozoologica
|
2016
|
vol. 55
|
issue 1
PL
The re-examination of the lightly calcified Arctic coccolithophore species, Papposphaera sagittifera, has some inherent challenges due to the research history on this taxon. It is thus obvious in retrospect that the species description based on just a single specimen does not adequately account for the true identity of this taxon. Today we are aware of the existence of at least three species of Papposphaera that have basically the same calyx design while being differentiated based on patterns of central area calcification. In order to remedy this we emend here the description of P. sagittifera and provide an epitype for the species. When realizing that species pairs of Papposphaera and Turrisphaera share a life history, the new combination, P. borealis, was established to accommodate P. sagittifera and T. borealis. However, it turns out that ‘sagittifera’ is in fact the senior epithet by a few months, which means that the correct name for the species is P. sagittifera with T. borealis added as a synonym. While the P. sagittifera HET and HOL morphological variability across Arctic sites clearly leaves the impression of a single, fairly well defined species, the situation is different with respect to the occurrence of P. sagittifera in Antarctic waters. While there are obvious similarities between P. sagittifera HET across the Polar Regions there are also subtle differences, and most importantly it has been found that the Antarctic P. sagittifera shares a life history with a species of Turrisphaera that is markedly different from T. borealis. While awaiting molecular evidence the Antarctic material is tentatively referred to as P. sagittifera cfr.
3
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Ventimolina stellata gen. et sp. nov. (Haptophyta, Papposphaeraceae) from Warm Water Regions

81%
Thomsen H. A., ØSTERGAARD J. B., CROS L.
Acta Protozoologica
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2015
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vol. 54
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issue 4
PL
It has been known for some time that the distinctive polar weakly calcified coccolithophores are also present in samples from lower latitudes. While polar species may actually have a geographic range that vastly extends beyond the polar realms, it is often the case that the warm water regions contribute species that can be allocated to genera previously described based on polar material. We are currently in the process of formally dealing with the warm water species diversity affiliated with the family Papposphaeraceae. In this paper we describe a new genus and species Ventimolina stellata based on material from the Andaman Sea (type locality) and the NW Mediterranean.
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