Life Cycle, Morphology, Ontogenesis, and Phylogeny of Bromeliothrix metopoides nov. gen., nov. spec., a Peculiar Ciliate (Protista, Colpodea) from Tank Bromeliads (Bromeliaceae)

Bromeliothrix metopoides was discovered in tank bromeliads from Central and South America. Pure cultures could be established in various media stimulating growth of its food, i.e. bacteria and heterotrophic flagellates of the genus Polytomella. The new ciliate was investigated in the light- and scanning electron microscope, with various silver impregnation techniques, and with molecular methods, using the small-subunit rDNA. The morphology and its changes during the life cycle are documented by 167 figures and a detailed morphometry. Bromeliothrix metopoides is about 27-55 × 22-36 μm in size and has a complex life cycle with Metopus-shaped, bacteriophagous theronts and trophonts (microstomes) and obovate, flagellate-feeding macrostomes having a large, triangular oral apparatus. The thin-walled resting cysts of the theronts and trophonts are uniquely ellipsoidal, while the thick-walled cyst of the macrostome morph is globular. Reproduction occurs in freely motile condition either by binary fission or polytomy, producing a unique, motile "division chain" composed of four globular offspring, of which the central ones are connected by a curious, plug-like holdfast. Division is associated with a complete reorganization of the parental oral and somatic infraciliature. Stomatogenesis is merotelokinetal as in other members of the order Colpodida. The right polykinetid is generated by the rightmost postoral kinety, while the left polykinetid is produced by the two left postoral kineties and five left side kineties. The division in freely motile condition resembles the Exocolpodidae Foissner et al., 2002, to which Bromeliothrix is tentatively assigned, differing from Exocolpoda mainly by the formation of a macrostome morph and a division chain. Bromeliothrix has a ciliary and silverline pattern typical for members of the family Colpodidae. This matches the molecular classification which, however, hardly reflects the outstanding division and life cycle, suggesting some decoupling of morphological and molecular evolution. The specific morphological and ontogenetic traits of Bromeliothrix are interpreted as adaptations to the highly competitive habitat, favouring r-selected life strategies. Bromeliothrix metopoides is widespread in various tank bromeliads and can be easily cultivated in a wide variety of limnetic and terrestrial media. Thus, it remains obscure why this ciliate is restricted to tank bromeliads, i.e. did not occur in about 2,000 soil and freshwater samples investigated globally, including some 100 samples from Central and South America.     

Morphology and infraciliature of two new marine ciliates, Paracyrtophoron tropicum nov. gen., nov. spec. and Aegyria rostellum nov. spec. (Ciliophora, Cyrtophorida), isolated from tropical waters in southern China

The morphology and infraciliature of two new marine cyrtophorid ciliates, Paracyrtophoron tropicum nov. gen., nov. spec. and Aegyria rostellum nov. spec., isolated from tropical waters in southern China, were investigated using live observation and protargol impregnation methods. Paracyrtophoron nov. gen. differs from the closely related Cyrtophoron by lack of fragment kinety at anterior ends of right somatic kineties and thigmotactic cilia in posterior portion of ventral surface, while from the well-defined Chlamydodon by lack of the cross-striped band around the periphery of the somatic field. Paracyrtophoron tropicum nov. spec., the type of the new genus, can be recognized by the combination of the following characters: cell size about 150-175×70-90μm in vivo; elliptical to kidney-shaped in outline, dorsoventrally flattened about 2.5:1; conspicuous cortical granules; one canal-like depression extending from postoral area to subcaudal region of cell; ca. 90 somatic kineties; 12-16 nematodesmal rods; one or two terminal fragments on dorsal side. Aegyria rostellum is characterized by the following features: size about 90-150×40-70μm in vivo, triangular or ear-shaped body with broad anterior end, having a rostriform structure and pigment spots, 56-63 somatic kineties, one preoral kinety, three or four circumoral kineties, and 32-42 nematodesmal rods. Based on previous and current studies, the definition for the genus Aegyria is updated: body dorsoventrally flattened; oral ciliature consisting of one preoral and several circumoral kineties; podite located in posterior ventral region and surrounded by somatic kineties; no obvious gap between right and left somatic kineties; postoral and left somatic kineties progressively shortened posteriorly from right to left. Additionally, two new combinations were proposed.     

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.     

Two new species of symbiotic ciliates from the respiratory tract of cetaceans with establishment of the new genus Planilamina n. gen. (Dysteriida, Kyaroikeidae)

Examination of mucus discharged from the blowhole of Atlantic bottlenose dolphin (Tursiops truncatus) at Marine Life Oceanarium, Gulfport, Mississippi, and false killer whale (Pseudorca crassidens) and Atlantic bottlenose dolphin at SeaWorld Orlando, Orlando, Florida, using live observations and protargol impregnation revealed mixed infections of Kyaroikeus cetarius and two new species. Planilamina n. gen. is characterized by a C-shaped argentophilic band located along the laterally flattened margin of cell and extending from the cell apex to subposterior cone-shaped podite; a deep oral cavity containing one short preoral kinety, two circumoral kineties, seven to 13 infundibular kineties, and a cytostome; a broadly funnel-shaped cytopharynx reinforced by argentophilic fibers but without nematodesmata; closely packed postoral kinetofragments set in a pocket located anterior left of the podite; and somatic kineties as a right field closely situated at the right surface and a left field bordering the anterior left margin of the oral cavity. The type species for the genus, Planilamina ovata n. sp., is distinguished from its sister species Planilamina magna n. sp. by the following characteristics: body size (28-65 x 20-43 microm vs. 57-90 x 40-63 microm), number of right field kineties (38-55 vs. 79-99), and position of the anterior end of the leftmost kinety in the right somatic field (anterior one-third vs. mid-body). The morphogenesis of Planilamina ovata is similar to that of K. cetarius. The diagnosis of Kyaroikeidae is emended to accommodate the new genus.     

Description of Two New, Mycophagous Soil Ciliates (Ciliophora, Colpodea): Fungiphrya strobli n. g., n. sp. and Grossglockneria ovata n. sp.

ABSTRACT The morphology and infraciliature of two new, mycophagous soil ciliates are described. Specimens were isolated from dried, rewetted soil samples with the non-flooded Petri dish method and investigated in vivo and with various silver impregnation techniques. Fungiphrya strobli n. g., n. sp. was discovered in the mud of rock-pools on the summit of Table Mountain, Republic of South Africa. It is a holotrichously ciliated, about 50 × 40 μm-sized grossglockneriid with the oral apparatus on the right side of the cell. The adoral ciliature, minute in all other members of the group, is well developed and has a mean of eight kineties forming a conspicuous left, oral polykinetid, highly reminiscent of that found in small species of the genus Colpoda . The ejected extrusomes have a unique, inflated distal end. Grossglockneria ovata n. sp. was discovered in leaf litter from the Lackawanna State Forest in Pennsylvania, USA. It differs from the other members of the genus by the ovate shape, smooth cortex, and the sparse, irregularly-shaped mucocysts. Taxonomic characters and ranking of grossglockneriids are discussed. Because of the complex, unique feeding tube associated with a unique feeding strategy, mycophagy, it is argued that grossglockneriid ciliates should be classified in a separate order, in spite of their close genetic relatedness to members of the order Colpodida.     

变藓棘毛虫的形态学重描述及细胞发生学研究

通过活体观察和蛋白银染色法对采自青岛沙滩半咸水的变藓棘毛虫Sterkiella histriomuscorum(纤毛门, 腹毛目)进行了形态学及细胞发生学研究。该种群形态学与前人报道的土壤及淡水种群基本一致: 虫体近长椭圆形, 活体大小约(100-160) m (40-75) m; 无皮层颗粒; 2938片口小膜; 额棘毛3根; 额腹棘毛4根; 口后腹棘毛3根; 横前腹棘毛2根; 横棘毛3-5根; 左右缘棘毛列分别由17-23、20-24根棘毛组成; 6列背触毛; 2枚大核。其主要发生学特征如下: (1)老口围带完全保留, 老波动膜解体重建; 后仔虫口原基独立发生; (2)额腹横棘毛为5原基次级发生式, 部分原基来自老棘毛解体, 以2:3:3:4:4方式分化为新棘毛; (3)缘棘毛原基产生于老结构中, 并向两极延伸逐渐形成前后仔虫的新结构; (4)背触毛发生为典型Oxytricha模式; (5)大核在发生过程中完全融合。研究对首次在半咸水生境中发现的变藓棘毛虫种群进行了活体形态学和纤毛图式描述, 补充了显微照片、性状统计数据及发生过程的细节信息。       

Redescription of Tintinnopsis parvula Jörgensen, 1912 (Ciliophora: Spirotrichea: Tintinnina), Including a Novel Lorica Matrix

Tintinnopsis parvulaJ?rgensen, 1912 has apparently a cosmopolitan distribution in the pelagial of marine and brackish coastal waters. The species is redescribed based on material from the Irish Sea off the Isle of Man, using live observation, protargol impregnation, and scanning electron microscopy. The agglomerated and stiff lorica measures 38-60 × 24-31 μm and is composed of a usually broadly obovate bowl and a slightly narrowed cylindroidal collar with an inner diameter of ~ 20 μm. The somatic ciliary pattern is of the most complex type, viz., it comprises a ventral, dorsal, and posterior kinety as well as a right, left, and lateral ciliary field. The left ciliary field comprises four kineties, the lateral field about ten kineties, and the right field five kineties. The oral primordium develops apparently apokinetally posterior to the lateral ciliary field and generates ~ 15 collar membranelles and one buccal membranelle. Two further populations were studied: one from the North Sea off the Island of Sylt, the other from brackish polder basins at the German North Sea coast; they match the Irish Sea specimens in all main features. The loricae formed in almost particle-free cultures have a thin wall composed of an irregular network of fibres and very few attached or interwoven particles. This matrix type differs from the other three types found in congeners. Hence, the matrix ultrastructure might represent a promising feature for a reliable subdivision of the species-rich genus TintinnopsisStein, 1867 in the future.     

Two new marine scuticociliates,Sathrophilus planus n. sp. and Pseudoplatynematum dengi n. sp., with improved definition of Pseudoplatynematum (Ciliophora,Oligohymenophora)

Two new marine scuticociliates, Sathrophilus planus n. sp. and Pseudoplatynematum dengi n. sp., isolated from coastal waters of Qingdao, northern China, were investigated using live observation and silver impregnations. Sathrophilus planus can be recognized by its elongate and conspicuously flattened body, ca. 16 somatic kineties, single postoral kinety, extremely elongated first kinety row of membranelle 1, and its marine habitat. Among these features, the structure of membranelle 1 is the most characteristic and enables this species to be easily distinguished from its congeners. Pseudoplatynematum dengi is characterized by the following features: cell surface conspicuously strengthened and notched; prominent spines both at anterior and posterior ends of cell; membranelles 1 and 2 three-rowed, membranelle 3 single-rowed; paroral membrane composed of two parts, anterior end of upper part extending to about level of membranelle 2; ca. 20 somatic kineties, one postoral kinety; single prolonged caudal cilium; contractile vacuole caudally positioned. The diagnosis of the genus Pseudoplatynematum was renewed to include some new characteristics revealed by silver impregnation methods.     

Morphology and ontogenesis of two new Hemiholosticha species (Ciliophora,Hypotrichia, Hemiholostichidae nov. fam.)

The morphology and ontogenesis of two new hypotrich ciliates, Hemiholosticha solitaria and Hemiholosticha germanica, were studied using live observation, protargol impregnation, and scanning electron microscopy. Both species share a medium-sized, almost globular body with a short anterior projection; two macronuclear nodules with a single micronucleus in between; a central contractile vacuole; three or four ventral, one postoral, one right and one left marginal cirral row; and three dorsal kineties extending along ribs. However, H. germanica is distinguished from congeners by a higher number of cirri in ventral rows R1 and R2 (3–6 vs. 2 cirri in each row). Hemiholosticha solitaria differs from congeners by having four (vs. three) ventral cirral rows and by the lack (vs. presence) of intracellular green algae. The ontogenesis of H. solitaria follows the H. pantanalensis mode in that (i) the oral primordium develops in a deep pouch and generates the first two cirral streaks in addition to adoral membranelles and undulating membranes, (ii) the undulating membrane anlage does not produce any cirri, and (iii) the longitudinal ventral cirral row R3 originates from two anlagen. The ontogenetic peculiarities along with the 18S rRNA gene phylogenies suggest classification of Hemiholosticha, Psilotrichides, and Urospinula into a new family, Hemiholostichidae.     

Morphology and Morphogenesis of Two Species of the Genus Lembadion (Ciliophora, Oligohymenophora): Lembadion lucens and Lembadion bullinum

ABSTRACT. The morphology and morphogenesis of two species of the genus Lembadion, L. lucens and L. bullinum , are described. In both species, left and right ventral kineties converge behind the mouth forming a postoral suture. Buccal infraciliature is formed by one polykinety and two very close paroral kineties (inner and outer). During stomatogenesis, the new oral structures originate from the paroral kineties. The inner paroral kinety forms the new adoral polykinety and regenerates the outer paroral kinety of the proter, while the paroral kineties of the opisthe originate from the outer paroral kinety of the parental cell. Somatic proliferation starts before the stomatogenesis at the equatorial level of the cell, and extends towards the poles forming an equatorial band. Two large invariant zones, anterior and posterior, remain in the dividing cell. Moreover, the kinetodesmal fibers disappear in the proliferation band during the bipartition (fission) process.     

Morphology and morphogenesis of a new marine cyrtophorid ciliate, Hartmannula sinica nov. spec. (Protozoa, Ciliophora, Cyrtophorida) from China

The living morphology, infraciliature and morphogenesis of a new marine cyrtophorid ciliate, Hartmannula sinica nov. spec., collected from Qingdao, north China, have been investigated. The new species is characterized by: size in vivo 90–130×40–50 μm, body long elliptical in outline, cilium-free field covered with a conspicuous alveolar layer; 24–31 ventral kineties, the rightmost 6–9 of which extend apically; 20–24 nematodesmal rods; about 15 sparsely distributed contractile vacuoles; a yellowish pigment spot is always present near the anterior tip of the cell. Morphogenetic events exhibit a pattern, which is homologous with that of related cyrtophorids. The main features are as follows: (1) preoral and circumoral kineties of opisthe develop from the oral primordium that forms in mid-body from sections of 3 postoral kineties, while parental preoral and circumoral kineties are retained; (2) parental cytostome and nematodesmal rods are resorbed in middle divisional stages and then replaced by newly formed structures; (3) the heteromerous macronucleus unifies in the late divisional stage.     

Morphology and Phylogeny of Two New Pleurostomatid Ciliates,Epiphyllum shenzhenense n. sp. and Loxophyllum spirellum n. sp. (Protozoa,Ciliophora) from A Mangrove Wetland,South China

ABSTRACT. The morphology, infraciliature, and small subunit (SSU) rRNA gene sequences of two new pleurostomatid ciliates, Epiphyllum shenzhenense n. sp. and Loxophyllum spirellum n. sp., isolated from a mangrove wetland near Shenzhen, South China, were investigated. Epiphyllum shenzhenense n. sp. is morphologically characterized by leaf‐shaped cell about 150 × 35 μm in vivo, usually with four contractile vacuoles, 20–29 right kineties and 10–26 left kineties, ca. four macronuclear nodules, and two types of extrusomes (i.e. short spindle‐shaped and long bar‐shaped). As a new species, L. spirellum n. sp. is distinguished from its congeners by its posterior dorsal margin twisted onto the left side, the distribution of extrusomes (evenly arranged along the oral slit, the posterior end, and clustered to 7–13 warts on dorsal margin), the subterminally positioned contractile vacuole, the number of kineties (8–10 on right side, 4–5 on left side), and its genetic distance from congeners. Phylogenetic trees based on the SSU rRNA gene sequence for both organisms were constructed, which indicate that Epiphyllum is a distinct genus and occupies a basal position in the Pleurostomatida clade; L. spirellum n. sp. falls well into the Loxophyllum clade, which has a close relationship with Litonotus and Spiroloxophyllum.     

红色伪角毛虫的形态学重描述及与相近种的比较(纤毛门,腹毛目)

利用活体观察、蛋白银染色技术对1种海水腹毛目纤毛虫-红色伪角毛虫Pseudokeronopsis rubra的青岛种群之活体形态和纤毛图式做了研究.其特征如下:虫体呈长带状,尾钝圆,身体柔软,高度可曲;皮层颗粒棕黄色,主要呈玫瑰花形分布,其余散布;表膜下具另1种无色、双面凹形颗粒.口围带小膜数为48～55;左、右缘棘毛各1列,中腹棘毛排成典型的锯齿状并延伸至横棘毛附近;额棘毛无明确分化,呈冠状排布并与中腹棘毛列相连续;口棘毛1根,额前棘毛2根;背触毛4列.大核90～140枚.伸缩泡位于体后左侧1/3处.经比较表明,尽管纤毛图式高度相似,P.rubra仍可以很容易地依据体色、伸缩泡的位置、皮层颗粒的大小、颜色、排布等活体特征与相近种区分.说明活体观察在纤毛虫种类鉴定中具有十分重要的作用.     

Pelagostrobilidium liui n. sp. (Ciliophora,Choreotrichida) from the Coastal Waters of Northeastern Taiwan and an Improved Description of Pelagostrobilidium minutum Liu et al., 2012

The number of somatic kineties in Pelagostrobilidium ranges from 4 to 6 according to the present state of knowledge. This study investigates Pelagostrobilidium liui n. sp. using live observation, protargol stain, and small subunit rDNA data sequencing. Pelagostrobilidium liui n. sp. is characterized by having a spherical‐shaped body, four somatic kineties, with kinety 2 spiraled around the left side of body, about six elongated external membranelles, and invariably no buccal membranelle. It differs from its most similar congener, Pelagostrobilidium minutum Liu et al., 2012 , in (i) cell shape; (ii) macronucleus width; (iii) oral apparatus; (iv) anterior orientation of kinety 2; (v) location where kinety 2 commences; (vi) arrangement of kinety 1; (vii) distance between the anterior cell end and the locations where kineties commence; and (viii) the presence of 12 different bases (including two deletions) in the small subunit rDNA sequences. The diagnosis of P. minutum Liu et al., 2012 is also improved to include the following new characteristics: invariably four somatic kineties; kineties 2 and 4 alone commence at the same level; kinety 2 originates from right anterior cell half on ventral side, extends sinistrally posteriorly, over kinety 1, around left posterior region, terminates near posterior cell end on dorsal side; kinety 1 commences below anterior third of kinety 2.     

Morphological redescriptions of four marine ciliates (Ciliophora: Cyrtophorida: Dysteriidae) from Qingdao, China

The morphology and infraciliature of four marine cyrtophorid ciliates isolated from Qingdao, China, were investigated. Based on the present work and on previous data, improved diagnoses for three rarely known species are provided: (1) Mirodysteria decora; small-sized marine Mirodysteria about 35–60 × 25–35 μm in vivo, oval in outline; body surface with two or three conspicuous dorsal spines and one caudal spine; three right kineties, the rightmost one extending dorso-apically; left frontal kineties reduced, each consisting of three basal bodies only; podite subcaudally positioned; two ventrally located contractile vacuoles. (2) Dysteria legumen; body oval with two longitudinal grooves on different plates; six right kineties, the rightmost two of which extend dorso-apically; two left frontal kineties and two ventrally located contractile vacuoles. (3) Dysteria proraefrons; body about 60 × 35 μm in vivo; six right kineties, the two rightmost of which extend dorso-apically and the leftmost one is considerably shortened; three left frontal kineties; two ventrally located contractile vacuoles. A population of D. derouxi with eight or nine right kineties is also briefly described. The current investigation further demonstrates high diversity and cosmopolitan distribution of this highly specialized group of benthic ciliates.     

Microscopical observations on four marine Dysteria species (Ciliophora, Cyrtophorida)

Four interesting strains of marine ciliates belonging to the genus Dysteria, collected from the coastal area of Qingdao, China, were investigated using living observations and silver impregnation methods. New data are supplied in redefinitions of three poorly known species, all of which had two contractile vacuoles. D. crassipes Claparède and Lachmann, 1859 has a rectangular body about 65 x 35 microm in vivo, with a podite subcaudal on the ventral side and a dorsal spine on some specimens; it has four right kineties, the rightmost two of which extend dorso-apically; both plates of examined specimens had a covering of ectosymbiotic bacteria. D. semilunaris (Gourret and Roeser, 1886) Kahl, 1931 has an oval body about 30 x 16 microm in vivo, with a caudal podite and a groove on the left plate; it also has four right kineties, the rightmost two of which extend dorso-apically. D. pectinata (Nowlin, 1913) Kahl, 1931 also has an oval body and caudal podite, but is larger at about 85 x 40 microm in vivo; it has seven right kineties, the rightmost two of which extend dorso-apically and the leftmost one is short and posterior. The fourth strain was D. brasiliensis Faria et al., 1922, which was found to vary in both shape and the presence or absence of a dorsal spine, it also hosts numerous rod-shaped ectosymbiotic bacteria on both plates of the cell. Based on information available, a key to the marine species that have been investigated by silver impregnation is updated.     

Pseudocollinia brintoni gen. nov., sp. nov. (Apostomatida: Colliniidae), a parasitoid ciliate infecting the euphausiid Nyctiphanes simplex

A novel parasitoid ciliate, Pseudocollinia brintoni gen. nov., sp. nov. was discovered infecting the subtropical sac-spawning euphausiid Nyctiphanes simplex off both coasts of the Baja California peninsula, Mexico. We used microscopic, and genetic information to describe this species throughout most of its life cycle. Pseudocollinia is distinguished from other Colliniidae genera because it exclusively infects euphausiids, has a polymorphic life cycle, and has a small cone-shaped oral cavity whose left wall has a field of ciliated kinetosomes and whose opening is surrounded on the left and right by 2 'oral' kineties (or ciliary rows) that terminate at its anterior border. Two related species that infect different euphausiid species from higher latitudes in the northeastern Pacific Ocean, Collinia beringensis Capriulo and Small, 1986, briefly redescribed herein, and Collinia oregonensis Gómez-Gutiérrez, Peterson, and Morado, 2006, are transferred to the genus Pseudocollinia. P. brintoni has between 12 and 18 somatic kineties, and its oral cavity has only 2 oral kineties, while P. beringensis comb. nov. has more somatic kineties, including 3 oral kineties. P. oregonensis comb. nov. has an intermediate number of somatic kineties. P. beringensis comb. nov. also infects Thysanoessa raschi (a new host species). SSU rRNA and cox1 gene sequences demonstrated that Pseudocollinia ciliates are apostome ciliates and that P. brintoni is different from P. beringensis comb. nov. High densities of rod-shaped bacteria (1.7 μm length, 0.2 to 0.5 μm diameter) were associated with P. brintoni. After euphausiid rupture, high concentrations of P. brintoni and bacteria cluster to form 3 to 6 cm long filaments where tomites encyst and transform to the phoront stage; this is a novel place for encystation. P. brintoni may complete its life cycle when the euphausiids feed on these filaments.     

Parastrombidinopsis minima n. sp. (Ciliophora: Oligotrichia) from the Coastal Waters of Northeastern Taiwan: Morphology and Small Subunit Ribosomal DNA Sequence

ABSTRACT. Parastrombidinopsis minima n. sp. is investigated, using live observations, protargol preparations, and molecular data. In living cells, the ranges of cell length are 85–95 μm, cell width 60–70 μm, and oral diameter 40–50 μm. In protargol‐impregnated specimens, cell length ranges between 43 and 71 μm, cell width between 23 and 42 μm, and oral diameter between 13 and 24 μm. The numbers of external oral polykinetids are 12–16 and of somatic kineties are 11–13. There are always two ovoid macronuclei (9–16 × 4–9 μm). Based on the analysis of morphologic data, the new species can be placed in the family Strombidinopsidae, but based on the small subunit rRNA gene sequence data, the Parastrombidinopsis species are more closely associated with strobilidiids and tintinnids.