Taxonomy and molecular phylogeny of three freshwater scuticociliates, with descriptions of one new genus and two new species (Protista, Ciliophora, Oligohymenophorea)

Integrative studies on the taxonomy and molecular phylogeny of four new Pleuronema species (Protozoa, Ciliophora, Scuticociliatia)

“…In the phylogenetic analyses by Foissner et al (2009) (when Histiobalantiidae sequences were first used in molecular phylogeny) and by Antipa et al (2016Antipa et al ( , 2020, Histiobalantiidae clustered with Schizocalyptra, which was nested within the Pleuronematidae, whereas in other phylogenetic analyses, including the present study (Fig. 6), Histiobalantiidae is invariably placed outside the Pleuronematidae with full support (Antipa et al 2016;Gao et al 2012Gao et al , 2013Gao et al , 2014Gao et al , 2017Lu et al 2021;Pan et al 2010Pan et al , 2015aPan et al , b, 2016Pan et al , 2020Zhang et al 2019). In consideration of the insufficient sampling of Pleuronema sequences in Foissner et al (2009) and the relatively low support for the position of Schizocalyptra in Antipa et al (2016Antipa et al ( , 2020, it is more credible that the phylogenetic position of Histiobalantiidae is outside the Pleuronematidae + Peniculistomatidae clade.…”

“…According to the phylogenetic analysis in Yi et al ( 2009), the genus Pleuronema is polyphyletic since two Schizocalyptra sequences nest within it forming a fully supported clade. The polyphyly of Pleuronema caused by Schizocalyptra was subsequently confirmed in most phylogenetic studies based on the SSU rRNA gene (Antipa et al 2016(Antipa et al , 2020Gao et al 2012Gao et al , 2013Gao et al , 2017Pan et al 2010Pan et al , 2015aPan et al , b, 2016Pan et al , 2020. However, in phylogenetic analyses based on nuclear or mitochondrial data, the genus Schizocalyptra falls outside of Pleuronema (Gao et al 2014;Lu et al 2021;Zhang et al 2019).…”

“…In recent years, several new species have been discovered, suggesting there is a large undescribed diversity and a need to conduct further studies on this genus (Pan et al 2015a , b , 2016 ; Wang et al 2008a , b , 2009 ). Molecular phylogenetic analyses have increasingly been applied in modern taxonomic studies on ciliated protists, and the polyphyly of Pleuronema has been widely reported (Antipa et al 2016 , 2020 ; Gao et al 2012 , 2013 , 2017 ; Pan et al 2010 , 2015a , b , 2016 , 2020 ; Yi et al 2009 ).…”

Taxonomy and Molecular Phylogeny of Three Species of Scuticociliates From China: Citrithrix smalli gen. nov., sp. nov., Homalogastra binucleata sp. nov. and Uronema orientalis Pan et al., 2015 (Protozoa, Ciliophora, Oligohymenophorea), With the Proposal of a New Family, Citrithrixidae fam. nov.

“…Recent studies on the ciliate fauna in coastal and freshwater habitats in China have revealed a much higher diversity of scuticocliates than was previously assumed (Song et al, 2009;Gao et al, 2012Gao et al, , 2013Gao et al, , 2014Gao et al, , 2017Pan H. et al, 2016;Hu et al, 2019;Zhang et al, 2019;Liu et al, 2020;Pan et al, 2020). Among these, the philasterids are generally well-studied in terms of the application of modern silver staining and molecular methods to determine their taxonomy (Song et al, 2009;Liu et al, 2017).…”

“…Among these, the philasterids are generally well-studied in terms of the application of modern silver staining and molecular methods to determine their taxonomy (Song et al, 2009;Liu et al, 2017). Six new genera and 22 new species have been added to the order Philasterida Small, 1967 since the beginning of the Twentyfirst century (Aescht, 2001;Gong et al, 2007;Jankowski, 2007;Pan et al, 2020), which implies the diversity of this group may be underestimated.…”