A Huge Diversity of Metopids (Ciliophora, Armophorea) in Soil from the Murray River Floodplain, Australia. II. Morphology and Morphogenesis of Lepidometopus platycephalus nov. gen., nov. spec.

Abstract

Abstract. The morphology and morphogenesis of a new Australian metopid ciliate, Lepidometopus platycephalus nov. gen., nov. spec., were studied using live observation, various silver impregnation methods, scanning electron microscopy, and morphometry. The new genus is outstanding in having epicortical scales (lepidosomes) and a strongly flattened and distinctly projecting preoral dome. Diagnostic features of L. platycephalus include a small, reniform body carrying an elongated caudal cilium, about 11 ciliary rows, and an adoral zone composed of an average of 11 polykinetids. The morphogenesis of L. platycephalus matches data from other metopids in that (1) the body is drastically re-shaped, (2) the parental oral structures are reorganized but do not contribute to the daughter oral ciliature, (3) the opisthe's adoral polykinetids originate pleurotelokinetally, (4) the opisthe's paroral membrane is formed via re-arrangement of the posterior portion of the first two perizonal rows, and (5) the opisthe's perizonal stripe is made by three parental perizonal rows and two dorsolateral ciliary rows. The morphogenetic data corroborate phylogenetic analyses in that caenomorphids are only superficially similar to metopids; metopids and clevelandellids are closely related; and litostomateans are the best candidates for a sister group of the metopid-clevelandellid assemblage within the SAL superclade.

Morphology, morphogenesis, and molecular characterization of Castula specialis sp. nov. (Ciliophora, Armophorea, Metopida)

“…However, the cell division pattern of Castula specialis sp. nov. differs in some details from that in other metopids (Foissner & Agatha, 1999;Vďačný & Foissner, 2017: (1) all dome kineties are involved in the formation of the new adoral membranelles (vs. only some dome kineties in Lepidometopus platycephalus and M. boletus; although not explicitly stated, all dome kineties participate in this process in Metopus hasei and M. inversus). Here, the ratio between the number of dome kineties involved and the total number of dome kineties is assessed for the first time, as it might be of taxonomic significance.…”

“…General terminology mainly follows Lynn (2008), Foissner and Agatha (1999), Foissner (2016), Foissner (2017), andBourland et al (2020). In metopids, "setae" refer to the long cilia that can stiffen and are originated over the posterior one-quarter to one-third of the cell, different from caudal cilia that originate from the rear cell (Bourland et al, 2020).…”

“…Cell division is a gradual process, and the timing is basically in the same as described by Vďačný and Foissner (2017). Accordingly, we consider those "late early dividers" whose perizonal stripe elongates to the posterior body portion (Figures 4E-G and 5E-G) and specimens whose opisthe is slightly longer than the proter as "early late dividers" (Figures 6C,D and 8A).…”

Morphology and phylogenetic position of three anaerobic ciliates from the classes Odontostomatea and Muranotrichea (Ciliophora)

“…Anaerobic ciliates have received increased attention during the last decade. Most of the published studies deal with their taxonomy, diversity, and phylogenetic position using standard methods, for example, protargol impregnation, scanning electron microscopy, and single‐gene phylogenies (Bourland et al, 2014, 2017a, 2017b, 2020, 2022; Bourland, Rotterová, & Čepička, 2018; Bourland, Rotterová, Luo, & Čepička, 2018; Bourland & Wendell, 2014; Campello‐Nunes et al, 2020, 2022; da Silva‐Neto et al, 2016; Fernandes et al, 2018; Foissner, 2016a, 2016b; Li et al, 2017; Li, Zhuang, Pérez‐Uz, et al, 2021; Li, Zhuang, Wang, et al, 2021; Méndez‐Sánchez et al, 2022; Nitla et al, 2019; Orsi et al, 2012; Paiva et al, 2017; Poláková et al, 2021; Rotterová et al, 2018; Vďačný et al, 2019; Vďačný & Foissner, 2017a, 2017b, 2019; Zhuang et al, 2021, 2022). Other studies have provided insights into features of their anaerobic lifestyle, for example, evolution, metabolism, and symbioses with various prokaryotes (Beinart et al, 2018; Lewis et al, 2018; Muñoz‐Gómez et al, 2021; Newbold et al, 2015; Omar et al, 2017; Rotterová et al, 2022).…”

Morphology and phylogeny of a new soil ciliate, Colpodidium zelihayildizi n. sp. (Ciliophora, Nassophorea, Colpodidiidae), from Van, Turkey

“…Although there are close to 1000 species of ciliates that have been discovered and defined from terrestrial habitats (Foissner, 1993;Foissner et al, 2002), it has been estimated that this number would be much higher if the unexplored regions of the world were taken into consideration (Finlay and Fenchel, 1999;Foissner et al, 2002;Chao et al, 2006;Foissner et al, 2008). In recent years, molecular taxonomic studies have shown that many of the ciliate species that are morphologically indistinguishable, and the number of ciliates is far beyond what has been predicted (Vďačný and Foissner, 2017;Warren et al, 2017).…”