A new oligotrich (Ciliophora, Oligotrichia) from Argentina, with redefinition of Novistrombidium Song and Bradbury

Overview of the Diversity, Phylogeny and Biogeography of Strombidiid Oligotrich Ciliates (Protista, Ciliophora), With a Brief Revision and a Key to the Known Genera

“…Species of Novistrombidium are divided into two distantly related assemblages, which corresponds with the separation of this genus into two subgenera and may support their raising to genus rank ( Agatha and Strüder-Kypke, 2014 ; Küppers et al, 2019 ). The subgenus Novistrombidium ( Novistrombidium ) is monophyletic whereas the subgenus Novistrombidium ( Propecingulum ) is not monophyletic as each of its species clusters with other genera.…”

“… Küppers et al (2019) considered the morphological differences between these two subgenera to be sufficient for them to be elevated to genus rank. However, considering the limited numbers of known species in these two subgenera, we prefer to adopt a conservative approach pending the availability of more morphological and molecular data from more taxa.…”

“…The somatic ciliature of most strombidiids usually includes a girdle kinety (GK) and a ventral kinety (VK) although there is considerable variation of these two among the 12 genera of the family Strombidiidae and in some species the ventral kinety is lacking ( Lynn, 2008 ; Song et al, 2009 ; Agatha, 2011 ). Since the first strombidiid species, Strombidium sulcatum (Claparède and Lachmann, 1859), was described, over 100 nominal species have been reported worldwide ( Shen et al, 2018 ; Wang et al, 2018 , 2019 ; Küppers et al, 2019 ; Song et al, 2019 ; Liu W. et al, 2021 ). Nevertheless, although the systematics of strombidiids have been frequently discussed, there are many disparities between the molecular and morphological data, especially at the genus and species levels ( McManus and Katz, 2009 ; Agatha and Strüder-Kypke, 2014 ).…”