Ribosomal RNA Genes Challenge the Monophyly of the Hyalospheniidae (Amoebozoa: Arcellinida)

Abstract

To date only five partial and two complete SSU rRNA gene sequences are available for the lobose testate amoebae (Arcellinida). Consequently, the phylogenetic relationships among taxa and the definition of species are still largely dependant on morphological characters of uncertain value, which causes confusion in the phylogeny, taxonomy and the debate on cosmopolitanism of free-living protists. Here we present a SSU rRNA-based phylogeny of the Hyalospheniidae including the most common species. Similar to the filose testate amoebae of the order Euglyphida the most basal clades have a terminal aperture; the ventral position of the pseudostome appears to be a derived character. Family Hyalospheniidae appears paraphyletic and is separated into three clades: (1) Heleopera sphagni, (2) Heleopera rosea and Argynnia dentistoma and (3) the rest of the species from genera Apodera, Hyalosphenia, Porosia and Nebela. Our data support the validity of morphological characters used to define species among the Hyalospheniidae and even suggest that taxa described as varieties may deserve the rank of species (e.g. N. penardiana var. minor). Finally our results suggest that the genera Hyalosphenia and Nebela are paraphyletic, and that Porosia bigibbosa branches inside the main Nebela clade.

Toward the use of testate amoeba functional traits as indicator of floodplain restoration success

“…Morphological adaptation to the soil (i.e. shell compression and aperture in a ventral position) appeared independently in both groups [19,20]. Thus TA represent an interesting example of evolutionary convergence and hence an ideal test group for linking phylogeny and functional ecology.…”

The tropics as an ancient cradle of oribatid mite diversity

“…For some species, PCR amplification of 18S rDNA was difficult and several shorter fragments were amplified using the above-mentioned primers and s6mod (Nikolaev et al 2005) (modified for this study), 18S476fn (designed for this study) and Euk516f (Lara et al 2008) in the combinations 18Sforward…”

Environmental DNA COI barcoding for quantitative analysis of protists communities: A test using the Nebela collaris complex (Amoebozoa; Arcellinida; Hyalospheniidae)

“…COI has also been shown to give high taxonomic resolution in many microbial eukary-otic groups (Barth et al 2006;Chantangsi et al 2007;Heger et al 2010;Lin et al 2009;Nassonova et al 2010). For exam-ple, in the Hyalospheniidae, SSU rRNA does not allow to discriminating among closely related taxa (Lara et al 2008) while COI does (Kosakyan et al 2012(Kosakyan et al , 2013. The COI-based metabarcoding approach allows discrimination among taxa that are generally interpreted as biological species, for Metazoa (Hebert et al 2003;Ratnasingham and Hebert 2007) (but see Meyer and Paulay 2005;Moritz and Cicero 2004) and our recent work on Hyalospheniidae also supports this view Kosakyan et al 2013).…”