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Xenophyophores are important megafaunal organisms in the abyssal Clarion-Clipperton Zone (CCZ; equatorial Pacific), a region hosting commercially significant deposits of polymetallic nodules. Previous studies assigned those with attached, fan-like tests to Psammina limbata, a species described from the central CCZ based on morphology. Here, we redescribe the holotype of P. limbata and then show that limbata-like morphotypes collected in the eastern CCZ include three genetically distinct species. Psammina aff. limbata is closest morphologically to P. limbata. The others are described as P. microgranulata sp. nov. and P. rotunda sp. nov. These fan-shaped species form a well-supported clade with P. tortilis sp. nov., a morphologically variable species exhibiting features typical of both Psammina and Semipsammina. A second clade containing Psammina sp. 3, and two species questionably assigned to Galatheammina branches at the base of this group. The genus Psammina includes another 9 described species for which there are no genetic data, leaving open the question of whether Psammina as a whole is monophyletic. Our study increases the number of xenophyophore species described from the eastern CCZ from 8 to 11, with a further 25 morphotypes currently undescribed. Many additional species of these giant foraminifera undoubtedly await discovery in abyssal settings., (Copyright © 2018 The Author(s). Published by Elsevier GmbH.. All rights reserved.)

Vanhoeffenella is a common deep-sea monothalamous foraminifer, some species of which have a unique eye-like test morphology. Owing to its world-wide distribution, it has been recorded numerous times since the "heroic age" of the deep-sea exploration in the early 20th century. So far, only 4 species have been described, and no attempts have been made to estimate the real diversity of this peculiar genus. Over the last fifteen years, we have collected specimens of Vanhoeffenella from various deep-sea areas, providing the basis for an integrative taxonomy and biogeography of this genus. Here, we clarify the phylogenetic position of Vanhoeffenella and give an account of its diversity in the Atlantic, Arctic and Southern Oceans (the Weddell Sea) as revealed by genetic marker (SSU rDNA) and morphology. Our study shows that Vanhoeffenella branches within Clade F of monothalamids and incorporates at least 10 putative species. Some could be distinguished by either morphological or molecular features, but only the integrative taxonomic approach provides a robust way to assess their diversity. We examine the new material of the type species (V. gaussi Rhumbler), redescribe the poorly-known V. oculus Earland and describe formally a fifth species, V. dilatata sp. nov., (Copyright © 2017 Elsevier GmbH. All rights reserved.)

Reticulomyxids are organotrophic freshwater foraminifers typically placed within the radiation of early monothalamous Foraminifera. Though ubiquitous, reticulomyxids are rarely reported, which may be due both to their concealed life style and to inappropriate isolation techniques. Their taxonomic position is largely based on developmental stages of the life cycle. Here, we describe a new freshwater species, Dracomyxa pallida gen. nov. et sp. nov., isolated from submersed plant material. It has two possible life cycles including small cells, large plasmodia and encysted stages. Both types of development occur simultaneously in cultures derived from a single cell as well as in crude cultures. We amplified and sequenced a short sequence fragment of the 18S rRNA gene of the new isolate. Comparative phylogenetic analysis and molecular characterization indicate that it is a new reticulomyxid species, with Reticulomyxa filosa Nauss, Haplomyxa saranae Dellinger and Wobo gigas Hülsmann as the closest relatives. Unique features such as tripodal pediculated cysts and the lack of cleansing process justify the erection of a new genus., (Copyright © 2014 Elsevier GmbH. All rights reserved.)

Ribosomal DNA is commonly used as a marker for protist phylogeny and taxonomy because of its ubiquity and its expected species specificity thanks to the mechanism of concerted evolution. However, numerous studies reported the occurrence of intragenomic (intra-individual) polymorphism in various protists and particularly in Foraminifera. To infer to what extent the SSU rDNA intragenomic variability occurs in Foraminifera, we studied 16 foraminiferal species belonging to single-chambered monothalamids and multi-chambered Globothalamea, with one to six individuals per species. We performed single-cell DNA extractions and PCRs of a 600bp fragment of SSU rDNA, and sequenced 9 to 23 clones per individual for a total of 818 sequences. We found intragenomic variability in almost all species, even after excluding singleton mutations. Intra-individual sequence divergence ranged from 0 to 5.15% and was higher than 1% in 11 species. Variability was usually located at the end of stem-loop structures and included compensatory single nucleotide polymorphisms and expansion segments polymorphisms. However, the polymorphisms did not change the secondary structure of the rRNA. Our results suggest a non-concerted evolution of rRNA genes in Foraminifera. The origin of this variability and its implications for species identification in environmental DNA studies are discussed., (Copyright © 2014 Elsevier GmbH. All rights reserved.)

A new naked foraminifer, Haplomyxa saranae gen. nov. sp. nov., is described from an established cell line made from a single cell isolated from a freshwater garden pond. The new species was morphologically close to Reticulomyxa filosa, the only valid naked freshwater foraminifer species. However the two species differed when it came to the morphology of the cell body, the number of cysts, and the nutrition. The 18S rRNA gene had one of the longest sequences to date (4863 nucleotides), and it contained many insertions that are typical of Foraminifera. The size of this gene was 45% longer than the one of R. filosa due to the elongation of A+T rich regions, but molecular phylogeny based on conserved regions of the 3'-end placed the new species in the same morphological clade K. This report includes both morphological and genetic data which undoubtedly show that the new species is a new naked freshwater foraminifer and the second species of the clade K., (Copyright © 2014 Elsevier GmbH. All rights reserved.)

Kleptoplastidy is the ability of heterotrophic organisms to preserve chloroplasts of algal preys they eat and partially digest. As the sequestered chloroplasts stay functional for months, the "host" becomes photosynthetically active. Although remaining a marginal process, kleptoplastidy was observed in different protist lineages, including foraminifera. Previous studies showed at least eight species of the foraminiferal genera Haynesina and Elphidium grazing on diatoms and husbanding their chloroplasts. In order to characterize more precisely the origin of kleptochloroplasts in these genera, we obtained 1027 chloroplastic 16S rDNA sequences from 13 specimens of two Haynesina and five Elphidium species. We identified the foraminiferal kleptochloroplasts using a reference phylogeny made of 87 chloroplastic sequences of known species of diatoms and brown algae. All the analyzed specimens were performing kleptoplastidy and according to our phylogenetic analyses they seem to retain exclusively chloroplasts of diatom origin. There is no apparent specificity for the type of diatom from which chloroplasts originated, however some foraminiferal species seem to accept a wider range of diatoms than others. Possibly the diversity of kleptochloroplasts depends on the type of diatoms the foraminiferans feed on., (Copyright © 2010 Elsevier GmbH. All rights reserved.)