Morphology,morphogenesis and molecular phylogeny of a novel saline soil ciliate,Urosoma quadrinucleatum n. sp. (Ciliophora,Hypotrichia)

The morphology and morphogenesis of a new saline soil hypotrichous ciliate, Urosoma quadrinucleatum n. sp., collected from northwestern China, were studied based on live observations and protargol stained specimens. The new species is characterized as follows: size in vivo 90–130 × 20–30 μm; body outline elongate-elliptical with both ends broadly rounded; four macronuclear nodules; cortical granules present; paroral in front of endoral; usually 16 frontal-ventral-transverse cirri. Urosoma quadrinucleatum n. sp. has almost the same morphogenetic characteristics as its congeners U. gigantea and U. salmastra, and differs from other three congeners whose morphogenesis is known in the formation of the frontal-ventral-transverse cirral anlagen as well as the development of marginal and dorsal kineties anlagen. The sequence differences among U. quadrinucleatum n. sp. and other Urosoma species further support the validity of the present organism as novel species. Further, U. quadrinucleatum n. sp. clusters with U. salmastra in the phylogenetic analyses based on small subunit ribosomal RNA gene (SSU rDNA) sequence data.     

Morphology,Morphogenesis, and Molecular Phylogeny of a New Soil Ciliate,Sterkiella multicirrata sp. nov. (Ciliophora,Hypotrichia) from China

The morphology and morphogenesis of a new soil hypotrich ciliate, Sterkiella multicirrata sp. nov., was investigated using live observation and protargol staining. The new species is characterised by: body elliptical, 110–180 × 45–75 μm in vivo, an average of 35 adoral membranelles; usually 19 frontoventral‐transverse cirri, consisting of three frontal, five frontoventral, one buccal, four postoral ventral, two pretransverse, and four transverse cirri; four macronuclear nodules, and 2–5 micronuclei. S. multicirrata sp. nov. differs from its congeners mainly in the number of frontoventral‐transverse cirri and macronuclear nodules. Morphogenesis of the new species is similar to its congeners; the primary difference exists in the segmentation of the frontoventral‐transverse cirral anlagen, which is usually generated in a 1:2:3:3:5:5 pattern. Based on the small subunit ribosomal DNA sequence, the phylogenetic position of the new species is discussed.     

Morphology and Phylogeny of the Soil Ciliate Metopus yantaiensis n. sp. (Ciliophora,Metopida), with Identification of the Intracellular Bacteria

The morphology and infraciliature of a new ciliate, Metopus yantaiensis n. sp., discovered in coastal soil of northern China, were investigated. It is distinguished from its congeners by a combination of the following features: nuclear apparatus situated in the preoral dome; 18–21 somatic ciliary rows, of which three extend onto the preoral dome (dome kineties); three to five distinctly elongated caudal cilia, and 21–29 adoral polykinetids. The 18S rRNA genes of this new species and two congeners, Metopus contortus and Metopus hasei, were sequenced and phylogenetically analyzed. The new species is more closely related to M. hasei and the clevelandellids than to other congeners; both the genus Metopus and the order Metopida are not monophyletic. In addition, the digestion‐resistant bacteria in the cytoplasm of M. yantaiensis were identified, using a 16S rRNA gene clone library, sequencing, and fluorescence in situ hybridization. The detected intracellular bacteria are affiliated with Sphingomonadales, Rhizobiales, Rickettsiales (Alphaproteobacteria), Pseudomonas (Gammaproteobacteria), Rhodocyclales (Betaproteobacteria), Clostridiales (Firmicutes), and Flavobacteriales (Bacteroidetes).     

Morphology and Molecular Phylogeny of a New Haptorian Ciliate,Chaenea mirabilis sp. n., with Implications for the Evolution of the Dorsal Brush in Haptorians (Ciliophora,Litostomatea)

We discovered a new haptorian ciliate, Chaenea mirabilis sp. n., in brackish water collected near the town of Busan, Korea. Its morphology was studied using standard taxonomical methods and its phylogenetic relationships were assessed by phylogenetic analysis of the 18S rRNA gene. Chaenea mirabilis is distinguished from all congeners by the combination of the following traits: (i) a narrowly bursiform to flask‐shaped, 60–100 μm long body; (ii) 11–21 doughnut‐shaped or sometimes horseshoe‐shaped macronuclear nodules; (iii) two types of extrusomes: type I is rod‐shaped and 6–8 μm long, while type II is narrowly to broadly teardrop‐shaped and only 1.5–2 μm long; (iv) highly refractive special granules tightly arranged between the first and second brush row, forming a conspicuous bulge; and (v) 12–13 somatic kineties. In the 18S rRNA gene phylogeny, C. mirabilis clustered with full support with other congeners. However, there was no statistical support for classification of Chaenea into the families Fuscheriidae, Acropisthiidae, or Trachelophyllidae, but a sister relationship with the Lacrymariidae could not be excluded. Therefore, we establish a new family, Chaeneidae, within the order Lacrymariida. This affiliation is strongly corroborated by the distinctly subapical dorsal brush bearing cilium‐like bristles.     

MOLECULAR PHYLOGENY OF THE GREEN ALGAL ORDER PRASIOLALES (TREBOUXIOPHYCEAE,CHLOROPHYTA)1

The systematics of the Prasiolales was investigated by phylogenetic inference based on analyses of the rbcL and 18S rRNA genes for representatives of all four genera currently attributed to this order (Prasiococcus, Prasiola, Prasiolopsis, Rosenvingiella), including all type species. The rbcL gene had higher sequence divergence than the 18S rRNA gene and was more useful for phylogenetic inference at the ranks of genus and species. In the rbcL gene phylogeny, three main clades were observed, corresponding to Prasiola, Prasiolopsis, and Rosenvingiella. Prasiococcus was nested among species of Prasiola occurring in subaerial and supralittoral habitats. Trichophilus welckeri Weber Bosse, a subaerial alga occurring in the fur of sloths in Amazonia, was closely related to Prasiolopsis ramosa Vischer. The species of Prasiola were grouped into three well‐supported clades comprising (i) marine species, (ii) freshwater and terrestrial species with linear blades, and (iii) terrestrial species with rounded or fan‐shaped blades. Sequence divergence was unexpectedly low in the marine group, which included species with different morphologies. For the 18S rRNA gene, the phylogenetic analyses produced several clades observed for the rbcL gene sequence analysis, but, due to very little sequence variation, it showed considerably lower resolution for inference at the species and genus levels. Due to the low support of some internal branches, the results of the analyses did not allow an unambiguous clarification of the origin and the early evolution of the Prasiolales.     

Molecular Phylogeny of Polychaos annulatum (Amoebozoa,Tubulinea, Euamoebida) Shows that Genus Polychaos Belongs to the Family Hartmannellidae

We have obtained a sequence of the 18S rRNA gene of the species Polychaos annulatum (Penard 1902) Smirnov et Goodkov 1998 using the isolation of a single nucleus from an amoeba cell. Attempts to amplify the 18S rRNA gene from the DNA of this species by conventional PCR were not successful, so we applied the whole genome amplification of the nuclear DNA followed by NGS sequencing. The 18S rRNA gene was found among the resulting contigs. The analysis unexpectedly shows that P. annulatum robustly groups within the family Hartmannellidae, but not Amoebidae. This finding warrants revision of the basic morphological criteria used to classify Euamoebida families and show that “proteus‐type” amoebae may belong to other families rather than Amoebidae. This makes taxonomic assignments of such species more complex and the borders between Euamoebida families more nuanced. It is getting evident that molecular data are necessary to clarify the position of species even in this most “classical” order of naked lobose amoebae.     

Taxonomic revision of Microcotyle caudata Goto, 1894 parasitic on gills of sebastids (Scorpaeniformes: Sebastidae), with a description of Microcotyle kasago n. sp. (Monogenea: Microcotylidae) from off Japan

Two species of microcotylid monogeneans, Microcotyle caudata Goto, 1894 and Microcotyle sebastisci Yamaguti, 1958, have been reported from fishes of the Sebastes inermis species complex and Sebastiscus marmoratus (Cuvier) (Scorpaeniformes: Sebastidae). So far, these parasite species have been distinguished by the size of the eggs and the number of testes, but based on morphological evidence including re-examination of the type-specimens and topotypes and molecular analysis, we consider M. sebastisci to be a junior synonym of M. caudata. As a result, M. caudata exhibits a wide host range, seven species from three genera and two families. A new species, Microcotyle kasago n. sp., is described based on material from S. marmoratus and differentiated from other congeners by means of morphological and molecular analysis.

     

Morphology and Molecular Phylogeny of Pseudocyrtohymena koreana n. g., n. sp. and Antarctic Neokeronopsis asiatica Foissner et al., 2010 (Ciliophora,Sporadotrichida), with a Brief Discussion of the Cyrtohymena Undulating Membranes Pattern

We discovered a new brackish water oxytrichid Pseudocyrtohymena koreana n. g., n. sp. in South Korea and investigated the new species on the basis of morphology, ontogenesis, and 18S rRNA gene sequences. The new genus has the 18 frontal‐ventral‐transverse cirri of typical oxytrichids with flexible body, cortical granules, Cyrtohymena undulating membranes (UM), and one left and one right marginal cirral row. Ontogenesis of the new species indicated that dorsal kinety anlage 3 stretches within the parental row without any fragmentations (Urosomoida pattern) and exclusively forms all caudal cirri. The new genus is morphologically similar to Cyrtohymena Foissner, 1989, but has the following distinctive features: (i) caudal cirri absent in dorsal kineties 1 and 2 (vs. present in Cyrtohymena); and (ii) dorsal kinety 3 nonfragmented (vs. fragmented in Cyrtohymena). Further, we collected an additional species Neokeronopsis asiatica Foissner et al. 2010, from King George Island, Antarctica, and the species shares the morphology of UM with Cyrtohymena. Herein, we describe the previously unidentified characteristics of N. asiatica (i.e., cortical granules, body flexibility, contractile vacuole, and 18S rRNA gene sequence). In addition, we obtained two 18S rRNA gene sequences from Cyrtohymena muscorum and Parasterkiella thompsoni to expand samples for phylogenetic analysis. Our 18S rRNA gene tree supports the hypothesis that the Cyrtohymena UM pattern might have evolved several times in hypotrichs (e.g., Neokeronopsidae, Oxytrichinae, and Stylonychinae).     

Periacineta mexicana n. sp. (Ciliophora,Suctoria, Discophryida), Epizoic on Mexican Backswimmers of the Genus Buenoa (Insecta,Hemiptera, Notonectidae)

ABSTRACT. A new species of suctorian in the genus Periacineta, epibiotic on aquatic bugs (Hemiptera, Heteroptera, Nepomorpha), is described on the basis of morphological characteristics of the cell body, lorica, tentacular placement, and stalk, and its 18S rRNA partial sequence gene. Periacineta mexicana n. sp. is a loricate suctorian with elongate body and rounded apical region; tentacles are distributed randomly over apical region and not grouped into fascicles. Macronucleus in adult is elongate and located centrally. The suctorian usually forms closely aggregated pseudocolonies. We provide morphological data based on optical and scanning electron microscopy. A comparison with similar congeners, and emended diagnosis of the genus Periacineta also are provided. The ciliates were found attached to the first two pairs of legs of Mexican notonectids Buenoa pallens and Buenoa spp. (backswimmers).     

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)

A new hypotrichous ciliate, Schmidtiella ultrahalophila gen. nov., spec. nov., was isolated from a solar saltern on the island of Sal, Cape Verde. The possession of only one short dorsal kinety clearly distinguishes S. ultrahalophila from other known hypotrichous genera and species. Further diagnostic characters include: a flexible and slender body, an average size of 85 × 15 μm in vivo; a bipartite adoral zone with two hypertrophied frontal adoral membranelles and nine to twelve ventral adoral membranelles; three frontal, one parabuccal, two frontoventral, two or three postoral ventral, and two or three frontoterminal cirri; and marginal cirral rows variable in number, usually one on each side. Ontogenetic data indicate the following: the frontal‐ventral cirri originate from six or five anlagen; the proter inherits the parental adoral zone; the frontal and ventral cirri originate from five or six anlagen; and the marginal cirral rows and the dorsal kinety tend to originate intrakinetally. Additional marginal rows are rarely derived from de novo anlagen. Based on its morphology, morphogenesis and its SSU rRNA phylogenetic placement, the new species should be assigned to the order Sporadotrichida Fauré‐Fremiet, 1961. Due to low taxon sampling, however, its exact position in this order remains enigmatic.     

Two Urosoma species (Ciliophora,Hypotrichia): A multidisciplinary approach provides new insights into their ultrastructure and systematics

The general morphology and ultrastructure of two soil hypotrichous ciliates, Urosoma emarginata and U. salmastra, were investigated using light microscopy, scanning electron microscopy and transmission electron microscopy. Phylogenetic analyses, based on the newly sequenced small subunit ribosomal (SSU) rRNA genes, were conducted on three U. emarginata populations and one U. salmastra population. Our findings support for the validity of Perilemmaphora Berger, 2008, a rankless taxon comprising spirotrich ciliates having a perilemma. The cortical granules of both species are extrusomes representing a new type of mucocyst in U. emarginata and possibly a new type of pigmentocyst in U. salmastra. Additionally, the lithosomes were revealed as subglobose structures composed of a low electron-dense, homogeneous inner part and an electron-dense outer part. The ultrastructural features of the cortical granules, together with ontogenetic and molecular phylogenetic data, suggest that the genus Urosoma might need to be divided. It is posited that ultrastructural features of hypotrichous ciliates in general may have important taxonomic value warranting further investigation.     

Morphology and morphogenesis of a new marine hypotrichous ciliate (Protozoa,Ciliophora, Pseudoamphisiellidae), including a report on the small subunit rRNA gene sequence

The morphology and morphogenesis of a new marine hypotrichous ciliate Pseudoamphisiella elongata sp. nov. isolated from mussel‐farming waters near Qingdao, China, are described based on living and protargol‐impregnated specimens. Morphologically, the new species can be distinguished from its known congeners by its elongate body shape, narrow oral field, having fewer dorsal kineties and caudal cirri, more marginal cirri, and differentiated pretransverse cirri. The identification as a new species is firmly supported by the sequences of the small subunit ribosomal rRNA (SSU rRNA) gene, compared with other known Pseudoamphisiella species, and the phylogenetic analysis. The morphogenetic characteristics can be summarized as follows: (1) the parental adoral zone of membranelles and undulating membranes are entirely rebuilt by the oral primordium, which develops de novo in the outermost region of the cortex; (2) the oral primordium in the opisthe and the frontoventral–transverse (FVT) anlagen in both dividers are formed independently on the cell surface; (3) an ‘extra’ marginal anlage originates to the right of the right marginal anlage, and develops into two or three ‘extra’ marginal cirri; (4) the FVT anlagen develop in the primary mode, and the last FVT streak contributes two migratory cirri (frontoterminal cirri), which are probably resorbed; (5) the right marginal anlagen in both dividers occur close together, independent of the old structure. © 2010 The Linnean Society of London, Zoological Journal of the Linnean Society, 2010, 158 , 231–243.     

Description of the Halophile Euplotes qatarensis nov. spec. (Ciliophora,Spirotrichea, Euplotida) Isolated from the Hypersaline Khor Al‐Adaid Lagoon in Qatar

The morphology, ontogenesis, and phylogenetic relationships of a halophile euplotid ciliates, Euplotes qatarensis nov. spec., isolated from the Khor Al‐Adaid Lagoon in Qatar were investigated based on live observation as well as protargol‐ and silver nitrate‐impregnated methods. The new species is characterised by a combination of features: the halophile habitat, a cell size of 50–65 × 33–40 μm, seven dorsal ridges, 10 commonly sized frontoventral cirri, two widely spaced marginal cirri, 10 dorsolateral kineties, and a double silverline pattern. The morphogenesis is similar to that of its congeners: (i) the oral primordium develops hypoapokinetally and the parental oral apparatus is retained; (ii) the frontoventral‐transverse field of five streaks gives rise to the frontal, ventral, and transverse cirri, but not to the cirri I/1 and the marginal cirri; (iii) the dorsal somatic ciliature develops by intrakinetal proliferation of basal bodies in two anlagen per kinety that are just anterior and posterior to the future division furrow; (iv) the caudal cirri are formed by the two rightmost dorsolateral kineties. The SSU rDNA sequence of E. qatarensis branches with full support in the Euplotopsis elegans–Euplotes nobilii–Euplotopsis raikovi clade. The closest related publicly available SSU rDNA sequence is the one of E. nobilii, with which E. qatarensis has 93.4% sequence similarity. Euplotes parawoodruffi Song & Bradbury, 1997 is transferred to the genus Euplotoides based on the absence of frontoventral cirrus VI/3.     

PLASTID DYNAMICS DURING SURVIVAL OF DINOPHYSIS CAUDATA WITHOUT ITS CILIATE PREY1

To survive, the marine dinoflagellate Dinophysis caudata Saville‐Kent must feed on the plastidic ciliate Myrionecta rubra (=Mesodinium rubrum), itself a consumer of cryptophytes. Whether D. caudata has its own permanent chloroplasts or retains plastids from its ciliate prey, however, remains unresolved. Further, how long D. caudata plastids (or kleptoplastids) persist and remain photosynthetically active in the absence of prey remains unknown. We addressed those issues here, using the first established culture of D. caudata. Phylogenetic analyses of the plastid 16S rRNA and psbA gene sequences directly from the three organisms (D. caudata, M. rubra, and a cryptophyte) revealed that the sequences of both genes from the three organisms are almost identical to each other, supporting that the plastids of D. caudata are kleptoplastids. A 3‐month starvation experiment revealed that D. caudata can remain photosynthetically active for ～2 months when not supplied with prey. D. caudata cells starved for more than 2 months continued to keep the plastid 16S rRNA gene but lost the photosynthesis‐related genes (i.e., psaA and psbA genes). When the prey was available again, however, D. caudata cells starved for more than 2 months were able to reacquire plastids and slowly resumed photosynthetic activity. Taken all together, the results indicate that the nature of the relationship between D. caudata and its plastids is not that of permanent cellular acquisitions. D. caudata is an intriguing protist that would represent an interesting evolutionary adaptation with regard to photosynthesis as well as help us to better understand plastid evolution in eukaryotes.     

Pseudonotohymena antarctica n. g., n. sp. (Ciliophora,Hypotricha), a New Species from Antarctic Soil

A new soil ciliate, Pseudonotohymena antarctica n. g., n. sp., from King George Island, Antarctica, is described based on live observation, protargol impregnation, and its 18S rRNA gene. The new genus Pseudonotohymena is morphologically similar to the genus Notohymena Blatterer and Foissner 1988 in the following characteristics: 18 fronto‐ventral‐transverse cirri, a flexible body, undulating membranes, dorsomarginal kineties, and the number of cirri in the marginal rows. However, Pseudonotohymena differs from Notohymena particularly in the dorsal ciliature, that is, in possessing a nonfragmented dorsal kinety (vs. fragmented). In addition, the molecular phylogenetic relationship of the new species differs from that of Notohymena species. On the basis of the morphological features, the genetic data, and morphogenesis, we establish P. antarctica n. g., n. sp. In addition, the cyst morphology of this species is described.     

Morphologic and molecular characterization of Apertospathula pilata n. sp., a novel freshwater spathidiid (Ciliophora,Litostomatea) from Idaho,USA

Order Spathidiida Foissner and Foissner, 1988 comprises a large group of morphologically diverse, primarily predatory, free living ciliates, the phylogeny of which has remained stubbornly unresolved. Families Arcuospathidiidae and Apertospathulidae are two morphologically similar groups established on the basis of differences in the morphology of the oral bulge and circumoral kinety. While Arcuospathidiidae is non-monophyletic in 18S rRNA gene analyses, the Apertospathulidae has been represented by only a single Apertospathula sequence in public databases. In this report, a novel freshwater species, Apertospathula pilata n. sp. is described on the basis of living observation, silver impregnation, and scanning electron microscopy. The phylogeny of the new species is assessed based on the rRNA cistron. The main features distinguishing A. pilata n. sp. from all congeners are: the oral bulge extrusomes (filiform, up to 25 µm long), the combination of body size (130–193 µm) and shape (spatulate), the extensive oral bulge length (41% of the cell length after protargol impregnation), and multiple micronuclei (one to five, two on average). The monophyly of Apertospathulidae Foissner, Xu and Kreutz, 2005 is rejected.     

Morphology and SSU rRNA gene‐based phylogeny of two Diophrys‐like ciliates from northern china,with notes on morphogenesis of Pseudodiophrys nigricans (Protozoa,Ciliophora)

Two free‐living marine euplotid ciliates, Pseudodiophrys nigricans and Diophrys japonica, collected from the coastal waters off Qingdao, northern China, were investigated using live observations and protargol impregnation methods. The cortical development of P. nigricans was observed during binary division. Although its general pattern of morphogenesis is similar to that of other Diophrys‐like species, three unusual features are noteworthy: 1) the frontoventral transverse cirral anlagen develop in the secondary mode, similar to that of Euplotes; 2) the undulating membrane anlage migrates far from the cytostome and does not split into two membranes; and 3) the parental adoral zone of membranelles remains nearly intact throughout the entire morphogenetic process. Diophrys japonica is redescribed based on a Chinese population and can be recognized by having one left marginal cirrus, densely arranged cortical granules, and a fragment kinety with three dikinetids. Phylogenetic analyses based on the small subunit rRNA (SSU rRNA) gene sequence data indicate that D. japonica is placed within the Diophrys clade and is most closely related to the well‐known D. apoligothrix. © J. Morphol., 2013. © 2012 Wiley Periodicals, Inc.