Foraminifera source details
Lecroq, B., Gooday, A.J., Tsuchiya, M. & Pawlowski, J. 2009. A new genus of xenophyophores (Foraminifera) from Japan Trench: morphological description, molecular phylogeny and elemental analysis. Zoological Journal of the Linnean Society 156: 455-464.
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Lecroq, B.; Gooday, A. J.; Tsuchiya, M.; Pawlowski, J.
2009
A new genus of xenophyophores (Foraminifera) from Japan Trench: morphological description, molecular phylogeny and elemental analysis
Zoological Journal of the Linnean Society
156: 455-464
Publication
The deep-sea floor is inhabited by a number of unusual and enigmatic taxa, unknown in shallow waters. These
include the xenophyophores, a group of giant protists that construct fragile agglutinated tests. Here, we describe
Shinkaiya lindsayi gen. et sp. nov., a new xenophyophore collected by the submersible Shinkai 6500 at a depth
of 5435 m near the Japan Trench. The phylogenetic analysis performed on its complete small-subunit ribosomal
DNA (SSU rDNA) sequence confirms that Sh. lindsayi sp. nov. is a foraminiferan that is closely related to another
xenophyophore, Syringammina corbicula Richardson, 2001, and to a monothalamous (single-chambered) foraminiferan
Rhizammina algaeformis Brady, 1879. In terms of morphology, the new genus resembles Syringammina, but
its test wall is thicker, softer, and more weakly cemented. Moreover, the SSU rDNA sequences of the two genera
are highly divergent. Mass spectra analyses reveal unusually high concentrations of some elements, such as lead,
uranium, and mercury. The granellare system (the cytoplasm and the organic sheath that encloses it) is apparently
devoid of barite crystals, which are usually abundant as intracellular inclusions in xenophyophores, but is rich in
mercury (with 12 times the concentration of mercury found in the surrounding sediment). Fecal pellets retained
within a tubular system (stercomare) concentrate heavy metals, including lead and uranium (respectively, two and
six times more than that of the sediment). Based on a comparison of the compositions of the agglutinated test wall,
the granellare, the stercomare, and the surrounding sediment, we discuss the impact of xenophyophores on their
habitat.
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Shinkaiya Lecroq, Gooday, Tsuchiya & Pawlowski, 2009 (original description)
Shinkaiya lindsayi Lecroq et al., 2009 (original description)
Shinkaiya lindsayi Lecroq et al., 2009 (original description)