Morphology and Molecular Phylogeny of Two Poorly Known Species of Protocruzia (Ciliophora: Protocruziida)

The ciliate genus Protocruzia is a highly confused group, which was formerly placed in the class Heterotrichea or Karyorelictea, and is according to the most recent system tentatively assigned to the class Spirotrichea. In the present study, the morphology, ciliary pattern, and molecular phylogeny of two poorly known species, Protocruzia tuzeti Villeneuve‐Brachon, 1940, and Protocruzia granulosa Kahl, 1933, isolated from coastal waters of China, were investigated. Protocruzia tuzeti differs from its congeners mainly in possessing 6 adoral membranelles, 8–11 somatic kineties, and postoral dikinetids. Protocruzia granulosa is characterized by its extremely slender body, three postoral kineties, and 13 or 14 somatic kineties. The morphogenesis of P. granulosa is similar to that of P. tuzeti, especially in the parakinetal mode of stomatogenesis and the reorganization of the parental paroral membrane; however, more than one somatic kinety joins in the formation of the oral primordium in P. granulosa. Phylogenetic analyses based on small subunit ribosomal RNA gene revealed that six Protocruzia species form a fully supported clade that does not belong to any ciliate class; therefore, our data support the establishment of the class Protocruziea Gao et al. (Sci. Rep., 6, 2016, 24874).     

Morphology,Ontogeny, and Phylogeny of Two Brackish Urostylid Ciliates (Protist,Ciliophora, Hypotricha)

The diversity of hypotrichous ciliates has encouraged numerous researchers to use a combination of morphological, morphogenetic, and phylogenetic data to provide a better understanding of the evolutionary relationships within this complex group. In this study, we investigate the morphology and morphogenesis of Pseudourostyla subtropica sp. nov., isolated from mangrove wetland. The new species can be distinguished from its congeners by the huge body size, many more adoral membranelles and marginal cirral rows, and numerous macronuclear nodules. In addition, we provide a morphological characterization of a population of Pseudourostyla nova Wiackowski 1988 from an estuarine habitat. The main events during binary fission of P. subtropica sp. nov. and the Chinese population of P. nova are also revealed to be conservative. The morphological, ontogenetic, and phylogenetic analyses based on the SSU rDNA sequences corroborate the monophyly of Pseudourostyla Borror, 1972, which corresponds well with previous research. The phylogenetic analyses also show that Pseudourostyla and Hemicycliostyla Stokes, 1886, both of which are assigned to the family Pseudourostylidae based on morphological and morphogenetic data, in fact fall into separated clades. The approximately unbiased tests, however, do not reject the possibility that the family Pseudourostylidae is a monophyletic lineage.     

Morphology,Cell Division,and Phylogeny of Uroleptus longicaudatus (Ciliophora,Hypotricha), a Species of the Uroleptus limnetis Complex

A Chinese population of the little‐known freshwater hypotrich Uroleptus longicaudatus was investigated with emphasis on its living morphology and infraciliature. The characteristic, tripartite body consists of a narrowed (cephalized) anterior portion, a slender trunk, and a long, slender, and strongly contractile tail occupying up to 30% of body length. Contracted specimens with a tail length of about 12% closely resemble Uroleptus limnetis which has, like U. longicaudatus, its type locality on the East Coast of the United States so that it cannot be excluded that these two species are synonymous. Thus, we propose to subsume these and few other little‐known species, which are not clearly distinguishable at the present state of knowledge, as U. limnetis complex. The morphogenesis of U. longicaudatus proceeds as in most congeners. The phylogenetic analyses reveal that Uroleptus is a monophyletic group, but due to the lack of detailed morphological data of the populations sequenced so far, the relationships within this taxon remain obscure. For the objective determination of the tail length of hypotrichs, we propose the “1/3‐method”, which says that the tail commences at that body width which corresponds one‐third of the maximum width. Paruroleptus ophryoglena Gelei, 1954 is transferred to Uroleptus: Uroleptus ophryoglena (Gelei, 1954) comb. nov.     

Morphology,Ontogeny, and Molecular Phylogeny of Two Freshwater Species of Deviata (Ciliophora,Hypotrichia) from Southern China

The morphology and partial morphogenesis of two freshwater hypotrichous ciliates, Deviata brasiliensis Siqueira‐Castro et al., 2009 and Deviata rositae Küppers et al., 2007, isolated from southern China, were investigated using live observation and protargol staining. Our populations resemble the original ones in terms of their live characters and ciliary patterns. The main determinable morphogenetic features of D. brasiliensis basically correspond with those of the type population. However, the origin of anlage V for either proter or opisthe is ambiguous: whether anlage V for the proter originates from parental frontoventral row 2 (the same as in the original population) or parental frontoventral row 3 (the same as in Deviata abbrevescens) or even de novo is not clear; the anlage V for the opisthe is possibly derived from frontoventral row 3 and further migrates to frontoventral row 2, like that in D. abbrevescens. In addition, the SSU rRNA gene was first sequenced for both species. Molecular phylogenetic analyses suggest that the genus Deviata is non‐monophyletic and has a close relationship with Perisincirra paucicirrata.     

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.     

Morphology and morphogenesis of Holosticha heterofoissneri nov. spec. from the Yellow Sea,China (Ciliophora,Hypotrichida)

The morphology and morphogenesis of the marine hypotrichous ciliate Holosticha heterofoissneri nov. spec. from mollusc culture in Qingdao, China are described based on living and protargol-impregnated specimens. The new species is characterized by: adoral zone slightly bipartite, consisting of on average 43 membranelles; constantly 5 dorsal kineties, and 12 pairs of cirri in midventral rows, and 14–16 macronuclear segments, which differs from the closely related species, H. foissneri. Its morphogenetic process shows the following features: (1) the parental AZM is retained unchanged and will be inherited by the proter, only the old UM reorganized; (2) FVT-cirral anlagen in both division parts derive from the breaking of primary primordia; (3) during the formation of FVT-cirral anlagen, most midventral cirri remain intact; and there appears an 'extra' anlage (EA) between the UMA and other FVT-cirral primordia; (4) the generation type of the dorsal kineties is of 'one group mode', the leftmost one of the 4 primordia fragmentates to form a new kinety; (5) at the early stage of morphogenesis, replication bands of macronuclear segments are apparently present.     

Morphology and Molecular Phylogeny of a New Hypotrich Ciliate,Pseudourostyla guizhouensis sp. nov. from Southern China,with Notes on a Chinese Population of Hemicycliostyla franzi (Foissner, 1987) Paiva et al., 2012 (Ciliophora,Hypotricha)

The morphology and molecular phylogeny of a soil hypotrich ciliate, Pseudourostyla guizhouensis sp. nov., collected from southern China, were investigated. Pseudourostyla guizhouensis sp. nov. has an elongate elliptical body measuring 180–310 × 65–85 μm in vivo; invariably two right and three or four left marginal rows; six or seven dorsal kineties; adoral zone consisting of 57–70 membranelles; 12–16 frontal cirri, one buccal cirrus, 13–20 midventral pairs, two frontoterminal cirri, two pretransverse cirri, and five to seven transverse cirri. Morphogenesis during physiological regeneration indicates that the marginal rows of each side originate from a common anlage that differentiates into several rows. Molecular phylogenetic analysis based on SSU rDNA sequence data reveals that P. guizhouensis sp. nov. clusters with the type species P. cristata (Jerka‐Dziadosz, 1964) Borror, 1972 and that the genus Pseudourostyla is monophyletic. The morphological characters of another soil hypotrich ciliate, Hemicycliostyla franzi (Foissner, 1987) Paiva et al., 2012, are also described based on a Chinese (Guizhou) population.     

Description of Muscotabanus gen. nov. and Muscotabanus rafaeli sp. nov. (Diptera: Tabanidae: Diachlorini) from Amazon Basin,Brazil

A new genus of Tabanidae mimetic of flies is described: Muscotabanus new genus, Muscotabanus rafaeli new species, based on 12 females collected in the state of Amazonas, Brazil. It is presented a discussion for separating the new genus from Diachlorini species which resemblance with sarcophagids flies. It is characterised by striped thorax, banded abdomen, long slender palpus subequal antenna length, labella predominantly membranous, except for a narrow sclerotised plate, basicosta bare, wing hyaline and stigma brown.     

Phylogeny of the order Tintinnida (Ciliophora, Spirotrichea) inferred from small- and large-subunit rRNA genes

Concatenated sequences of small- and large-subunit rRNA genes were used to infer the phylogeny of 29 species in six genera of Tintinnida. We confirmed previous results on the positions of major clusters and the grouping of various genera, including Stenosemella, the paraphyletic Tintinnopsis, the newly investigated Helicostomella, and some species of the polyphyletic Favella. Tintinnidium and Eutintinnus were found to be monophyletic. This study contributes to tintinnid phylogenetic reconstruction by increasing both the number of species and the range of genetic markers analyzed.     

Establishment of a new amphileptid genus, Apoamphileptus nov. gen. (Ciliophora, Litostomatea, Pleurostomatida), with description of a new marine species, Apoamphileptus robertsi nov. spec. from Qingdao, China

A new pleurostomatid genus Apoamphileptus is described, which is diagnosed as: Belonging to the Amphileptidae with spica on right side; on each side of the cell, a single perioral kinety, which encircles the cytostome and does not extend to the posterior end of the cell; somatic kineties of both sides near ventral margin shortened and forming a postoral suture; two to several extra fragments with densely arranged dikinetids located in anterior portion of left side. As the type species, the morphology and infraciliature of Apoamphileptus robertsi nov. spec., isolated from a shrimp-farming pond near Qingdao (Tsingtao), China, have been investigated using living observations and the protargol silver impregnation method. The diagnosis for this new species is: Apoamphileptus 90-180 x 30-60 microm in vivo, body elongate pyriform-shaped and slightly flattened; with one cross-striated band along the cytostome; 2-6 (generally 4) large macronuclear nodules, one micronucleus; 33-43 right somatic kineties; left side 6-8 kineties; two extra anterior fragments on left side; about 13 contractile vacuoles dispersed throughout whole body; extrusomes absent or not recognizable; marine habitat. Some morphologically related morphotypes are discussed and tabulated. Regarding the pattern of infraciliature and other morphological features, the well-described fresh-water species, Amphileptus claparedii Stein, 1867 is believed to be a member of this new genus, hence a new combination is suggested: Apoamphileptus claparedii (Stein, 1867) nov. comb.     

Molecular Phylogeny and Ontogeny of a New Ciliate Genus,Paracladotricha salina n. g., n. sp. (Ciliophora,Hypotrichia)

A hypotrichous ciliate, Paracladotricha salina n. g., n. sp., was discovered in hypersaline waters (salinity about 80‰) from Qingdao, China. Its morphology and some major ontogenetic stages were studied and the phylogenetic position was estimated using standard methods. Paracladotricha salina is characterized by a flexible, more or less slender body (size 50–120 × 20–35 μm), a gonostomatid oral apparatus, one short and two long frontoventral rows, four macronuclear nodules, almost completely reduced dorsal kineties 1–3, and a loss of several parts of the ciliature, namely, the slightly shortened ciliary row of the adoral membranelles, the paroral, and the buccal, the postoral and pretransverse ventral, the transverse, and the caudal cirri. The ontogenesis is rather simple: anlage II of both filial products and anlage III of the opisthe originate de novo, while anlagen IV and V are formed within the parental rows. This combination of features requires the establishment of a new genus, Paracladotricha, which is, according to the morphological data, closely related to Schmidingerothrix and Cladotricha. The small‐subunit rRNA gene was sequenced, indicating that P. salina is, as also demonstrated by the oral apparatus, a member of the gonostomatids. We provide a first, vague hypothesis about the phylogenetic relationships of the Gonostomatidae, Cladotrichidae, and Schmidingerotrichidae. However, since molecular data of the type species of these higher taxa are lacking, their validity and relationships remain obscure.     

Paraurosomoida indiensis gen. nov., sp. nov., an oxytrichid (Ciliophora,Hypotricha) from Kyongnosla Alpine Sanctuary,including note on non-oxytrichid Dorsomarginalia

Paraurosomoida indiensis gen. nov., sp. nov. was isolated from a soil sample collected from Kyongnosla Alpine Sanctuary in the Eastern Himalayas. The present study reports the morphology, morphogenesis, and molecular phylogeny inferred from 18S rDNA sequence. The study is based on live and protargol-impregnated specimens. Paraurosomoida indiensis is very flexible, measures about 90 × 25 μm in life and possesses citrine cortical granules randomly distributed singly and in small linear groups. Paraurosomoida indiensis has undulating membranes nearly in Oxytricha pattern; only 11 frontal-ventral cirri due to lack of all pretransverse ventral and transverse cirri; one dorsomarginal row and three bipolar dorsal kineties. Divisional morphogenesis resembles oxytrichids involving six parental cirri in primordia formation. Anlagen V and VI for both proter and opisthe are formed from two primary primordia originating from disaggregated cirri V/4 and V/3 respectively. Three dorsal kineties develop from within row anlagen without a kinety 3 fragmentation. Molecular analyses consistently place P. indiensis with soft bodied oxytrichids.     

Description of a new marine species of Askenasia Blochmann, 1895 (Ciliophora,Haptoria), with notes on its ecology

A marine planktonic ciliate, belonging to the genus Askenasia Blochmann, 1895, is described with notes on its distribution and ecology. Specimens of this new species were collected from four coastal sites across the northern hemisphere. Samples were collected between March and December, from depths of 1-20 m. Relatively low (< 1 ml(-1)) densities were recorded from Atlantic and Pacific Oceans and North Sea coastal sites, whereas samples from the English Channel suggested that this species has the ability to form blooms. Specimens were protargol-stained, revealing the key features of the genus, including the diagnostic sub-equatorial kinety belt consisting of three unciliated monokinetids. However, the species is larger than other Askenasia with a single distinctive, rope-like, scalloped macronucleus. This species also appears to have an extra somatic kinety belt, which may be present but has not been observed in other Askenasia species. Based on size, kinety structure, kinety number, and macronuclear shape a new species has been established.     

Aulacoseira calypsi sp. nov. (Coscinodiscophyceae) from an Amazonian lake,northern Brazil

This paper describes a new diatom species, Aulacoseira calypsi Tremarin, Torgan & Ludwig, from specimens in plankton samples from Água Preta lake. This Amazonian lake is a shallow mesotrophic environment situated in northern Brazil. The species is characterized by long filaments united by spatulate linking spines, obovate to conic separation spines, a valve surface variably ornamented, straight striae on the mantle, a narrow ringleist, and one row of sessile rimoportulae near the ringleist. Aulacoseira calypsi's morphometric features are compared with the following similar species: Aulacoseira nygaardii (Camburn) Camburn & Charles, Aulacoseira lacustris (Grunow) Krammer, Aulacoseira coroniformis Pearce & Cremer, Aulacoseira occulta Siver & Hamilton, Aulacoseira lancea Siver & Hamilton, Aulacoseira gessneri (Hustedt) Simonsen, and Aulacoseira islandica (Müller) Simonsen. The species shares similarities as to frustule size, striation pattern, and narrowness of ringleist; but differs in the morphology of separation and linking spines, and the number and position of the rimoportulae.     

Description of Discocriconemella mineira n. sp. and D. degrissei Males from Brazil

A new species of Discocriconemella and the male of Discocriconemella degrissei are described from Minas Gerais state of Brazil. Discocriconemella mineira n. sp. differs from D. discolabia by having a longer stylet (61-71 vs. 35-47 μm) and fewer body annuli (78-88 vs. 155-174), and from D. inarata by the longer stylet (61-71 vs. 51-61 μm) and shorter body length (253-342 vs. 354-486 μm). It differs from D. persae by having a shorter stylet, fewer body annuli, and a shorter post vulval body portion (Rv = 6-7 vs. 14-20). Discocriconemella mineira can be separated from D. degrissei by the head disc which is round in D. mineira and quadrilobate in D. degrissei. Males of D. degrissei resemble those of D. retroversa.     

Redescription of Rigidohymena inquieta (Stokes, 1887) Berger, 2011 as Metahymena inquieta gen. nov., comb. nov. (Ciliophora,Hypotricha) Based on Morphology,Morphogenesis, and Molecular Phylogeny

The morphology and morphogenesis of Rigidohymena inquieta (Stokes, 1887) Berger, 2011, isolated from a lawn soil in the campus of the University of Ulsan, Korea, was studied, using live observation and protargol impregnation. The molecular phylogeny was studied based on the SSU rRNA gene sequences. The morphology of the Korean population of R. inquieta matches the previously known populations; however, the morphogenetic pattern shows differences to the species R. candens in the involvement of cirrus V/3 in the anlagen formation. A novel genus namely Metahymena gen. nov. has been erected for the present species based on the ontogenetic difference, and the new combination Metahymena inquieta gen. nov., comb. nov. is proposed. The morphology, morphogenesis, distribution, and phylogeny of M. inquieta are presented. The morphologic and morphogenetic data corroborate the phylogenetic analyses as M. inquieta clusters among the stylonychid ciliates in a clade distant from Rigidohymena candens.     

Morphological Description and Molecular Phylogeny of Two Species of Levicoleps (Ciliophora,Prostomatida), L. taehwae nov. spec. and L. biwae jejuensis nov. subspec., collected in Korea

Two colepid ciliates, Levicoleps taehwae nov. spec. and L. biwae jejuensis nov. subspec., were collected from the brackish water of the Taehwa River and a small freshwater pond in Jeju Island, South Korea, respectively. Their living morphology, infraciliature, and small subunit (SSU) rRNA gene sequences were determined using standard methods. Barrel‐shaped L. taehwae nov. spec. is a small ciliate with an average size of 45 × 25 μm in vivo, about 15 ciliary rows each composed of 12 monokinetids and two perioral dikinetids, and two 20 μm‐long caudal cilia. The sequence length and GC content of the SSU rRNA gene are 1,669 bp, 44.5%. This novel species is similar in body size to Coleps hirtus, and has six armor tiers and hirtus‐type tier plates, and the same number of ciliary rows as C. hirtus; however, it can be distinguished from the latter by the absence of armor spines and its sequence similarity of SSU rRNA gene is about 92.8% which indicates that it is a distinct form. Levicoleps biwae jejuensis nov. subspec., is a medium colepid ciliate which has a barrel‐shaped body, about 22 somatic kineties and 16 transverse ciliary rows, three mini adoral organelles, and four 15 μm‐long caudal cilia. The sequence length and GC content of the SSU rRNA gene are 1,666 bp and 44.4%.