Multigene‐based phylogeny of Urostylida (Ciliophora, Hypotrichia), with establishment of a novel family

Abstract

The Urostylida is a major taxon of hypotrichs with many unresolved evolutionary relationships. Due to incomplete or inaccurate character states and a paucity of morphogenetic data, the phylogeny of several taxa within urostylids is unresolved. Molecular phylogeny studies based on single gene (SSU rDNA) data may lead to conflict between morphological classification and SSU rDNA tree. In this work, 20 new sequences (SSU rDNA, ITS1‐5.8S‐ITS2 and LSU rDNA) of five genera of urostylids are provided to further investigate the phylogenetic relationships of this group. The main findings are as follows: (i) the establishment of Hemicycliostylidae, a novel family presently including Hemicycliostyla and Australothrix, is supported by both single gene and concatenated phylogenies; (ii) all molecular data support the exclusion of Eschaneustyla from the family Epiclintidae; (iii) Australothrix, Bergeriella and Thigmokeronopsis are distinctly separated in all gene trees although they share the character that each posterior streak generates the ventral row together with the midventral pair; (iv) compared with closely related genera in all trees, that is Metaurostylopsis and Apourostylopsis, Neourostylopsis is characterized by having more than three frontal cirri arranged in distinct or indistinct corona rather than the length of the midventral complex; (v) Hemicycliostyla and Pseudourostyla, two morphologically similar genera, do not form a monophyletic group in all molecular trees, suggesting that the bicorona, multiple marginal cirral rows and high numbers of dorsal kineties may result from convergent evolution; (vi) species of Bakuella fall into three separate clades in all trees suggesting that this genus needs to be split.

Morphology, Morphogenesis and Molecular Phylogeny of a New Obligate Halophile Ciliate, Schmidtiella ultrahalophila gen. nov., spec. nov. (Ciliophora, Hypotrichia) Isolated from a Volcanic Crater on Sal (Cape Verde Islands)

“…PREVIOUS surveys have shown that hypotrichous ciliates are highly diverse and distributed in various habitats such as soil, freshwater, estuarine, marine, and even hypersaline environments (Berger 1999(Berger , 2006(Berger , 2008(Berger , 2011Chen et al 2017aChen et al ,b, 2018Harding and Simpson 2018;Foissner 2016, 2017;Lei et al 2009;Li et al 2018;Liu et al 2017;Luo et al 2017;Lyu et al 2018;Wang et al 2017). Thus far, three hypotrichous genera have been reported from hypersaline habitats: Apourosomoida Foissner et al 2002, Cladotricha Gaievska€ ıa, 1925, and Schimidingerothrix Foissner 2012.…”

Morphology of Two Eschaneustyla Species (Ciliophora, Urostylida), with Notes on Morphogenesis of Eschaneustyla lugeri

“…Although we could not establish a clonal culture for Eschaneustyla terricola and E. lugeri, the specimens used for morphological and molecular analyses were very likely conspecific because no other Eschaneustyla-like morphospecies were found during live observations and in the protargol preparations. This population of E. lugeri is identical with Eschaneustyla lugeri KY874005 sequenced by Lyu et al (2018).…”

“…Based on the similarity in frontal ciliature (multi-corona) and midventral complex (composed of midventral rows only), Berger (2006) assigned Eschaneustyla in Epiclintidae alongside Epclintes, but he claimed that further data are needed to evaluate this classification. Lyu et al (2018) found that Eschaneustyla and Epiclintes are distantly separated in phylogenetic trees, and classified Eschaneustyla as incertae sedis within Urostylida.…”

Morphology, morphogenesis and phylogeny of the new soil ciliate, Bistichella granulifera n. sp. (Protista, Ciliophora)

“…Cortical granules colourless, about 1 μm across, densely scattered throughout cell surface. [33][34][35][36][37][38] adoral membranelles, three enlarged frontal cirri and three or four buccal cirri arranged in a row. Three frontal rows, composed about three cirri in each.…”

“…Bistichella kenyaensis differs from the B. granulifera n. sp. by having body shape ellipsoid to slenderly ellipsoid, and usually widest anterior of mid-body (vs. elongated oval and widest at mid-body), the right frontoventral row with a very wide break in the middle quarters of body (vs. no break), fewer adoral membranelles (21-30 vs. 33-38) and cirri in the frontal rows (4-6 vs.7-10), frontoventral row I (9-20 vs. [26][27][28][29][30][31][32][33][34][35][36][37] and right marginal row (30-43 vs. 48-54), shorter frontoventral row I (terminates at 54% vs. 90% down length of body) and no cortical granules (vs. present) [4].…”