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Present study, investigates a poorly known species of the genus Sterkiella, i.e., S. tricirrata, based on two populations isolated from soil samples collected from the Colfiorito Regional Park, Umbria Region, Italy and from the Silent Valley National Park, India. Both populations showed a highly similar morphology, however different ontogenetic pattern in between. The study confirms the validity of the species S. tricirrata which was considered to be a species within the Sterkiella histriomuscorum complex. The main ontogenetic difference between S. tricirrata and other species of the genus Sterkiella is the different mode of formation of anlagen V and VI of the proter in the former. In the phylogenetic analyses, Sterkiella tricirrata clusters with Sterkiella sinica within the stylonychine oxytrichids, in a clade away from the type species (Sterkiella cavicola) of the genus Sterkiella. The study highlights the importance of ontogenetic as well as molecular data in shedding light on the polyphyletic behavior of the genus Sterkiella. A detailed description of S. tricirrata based on morphology, ontogenesis and molecular phylogenetic methods is presented. Further, the improved diagnosis has been provided for the genus Sterkiella and the poorly known species S. tricirrata. [ABSTRACT FROM AUTHOR]

In vitro laboratory experiments were conducted to determine the toxicity (per cent survival and LC50) of essential and non-essential heavy metals (cadmium, copper, nickel, lead and zinc) in four spirotrich ciliates: Euplotes sp., Notohymena sp., Pseudourostyla sp. and Tetmemena sp. isolated from three different freshwater ecosystems in the Delhi region, India. The toxicity of the heavy metals was found to vary among the different ciliates. Copper was most toxic (24 h-LC50 value ranged between 0.125 and 0.74 mg/l) and zinc was least toxic (24 h LC50 value ranged between 46.98 and 144.32 mg/l) to each of the ciliates. Of the four ciliates, Notohymena sp. had the highest tolerance limit to three heavy metals (Cu, Cd and Pb) out of the five tested. This study shows the high potentiality of using freshwater ciliates for monitoring the intensity and potency of ecological damage caused by heavy metals in aquatic ecosystems. [ABSTRACT FROM AUTHOR]

A hypotrichous ciliate, Paragonostomoides xianicum n. sp., was discovered in soil on the surface of the Xi’an Circumvallation, Xi'an, China. Its morphology and some major ontogenetic stages were studied and the phylogenetic position was estimated using standard methods Paragonostomoides xianicum n. sp. is characterized as follows: body size about 75–90 × 15–25 μm in vivo, elliptical and flexible; colourless mitochondrion-like cortical granules scattered throughout cell surface, about 0.8 × 0.6 μm in size; contractile vacuole positioned at mid-body; frontoventral row IV extends beyond buccal vertex and frontoventral row VI extends to about body end; frontoventral cirri not in pairs; transverse cirri absent; three caudal cirri; two macronuclear nodules and one to four micronuclei. The ontogenetic process in P. xianicum n. sp. is basically similar to that in Metagonostomum gonostomoidum and Gonostomum -species and featured by: frontoventral-transverse cirri develop in five-anlage pattern, the rearmost cirri generated in the two rightmost FV anlagen are not set off posteriorly (like an ordinary TC), as well as FVT-anlagen n and n-1 form in secondary mode in P. xianicum . Phylogenetic analyses based on small subunit ribosomal DNA sequence data reveal a close relationship of P. xianicum n. sp. with Cotterillia bromelicola and two Gonostomum -species. [ABSTRACT FROM AUTHOR]

Heterotrichs are generally larger than ciliates of other groups with a seemingly cosmopolitan distribution, and recent studies have demonstrated that they exhibit great biodiversity. In the present work, we investigated the morphology and small subunit rRNA (SSU rRNA) gene sequences of three heterotrichous species, including that of a new one, Anigsteinia paraclarissima spec. nov. The new organism is morphologically very similar to A. clarissima , however, it can be distinguished from the latter by the larger dimensions and more somatic kineties (25–32 vs. 18–26), and its sequence similarity of SSU rRNA gene is 97.14% which indicate that it is a distinct species. Detailed morphological and molecular data for Blepharisma bimicronucleatum are supplied together for the first time in this study. In addition, the morphology of a poorly known species, Spirostomum yagiui is redescribed and an improved species diagnosis is provided. Finally, based on phylogenetic analyses of SSU rRNA gene sequences data, the Spirostomum group contains two main clades based on the type of the macronucleus. Spirostomum yagiui was newly sequenced here and clustered with the other S. yagiui populations and positioned within the Spirostomum assemblage. The Anigsteinia clade, including A. paraclarissima and A. clarissima , clustered within the family Spirostomidae. [ABSTRACT FROM AUTHOR]

Reconstruction of evolutionary history of the ciliate order Spathidiida has proven elusive. There are weakly statistically supported deeper nodes in 18S rRNA gene phylogenies on one hand, while several statistically strongly supported clusters containing morphologically dissimilar taxa that usually lack any common apomorphies on the other hand. To clarify whether silent aspects of the spathidiid phylogeny are results of methodological problems of tree-building algorithms, we examined informativness of the macronuclear rRNA locus using an increased taxon and marker sampling as well as a complex statistical approach. Likelihood mapping revealed that the macronuclear rRNA locus has enough phylogenetic information to infer spathidiid relationships. However, some noise and conflicts hamper inference of deeper branching events, as documented by short parallelograms in the star-like central part of the split graphs and by low numbers of phylogenetically informative nucleotide homologies supporting deeper nodes of phylogenetic trees. Based on the diversification analyses and the γ-statistic, we assembled a body of evidence that the spathidiid phylogeny retains the signature of one or several rapid radiations in the Palaeozoic and a subsequent gradual extinction that has started in the Mesozoic. A combination of these two phenomena along with polyphyly of three large spathidiid genera ( Spathidium, Epispathidium and Arcuospathidium) are speculated to be the main reasons for fuzzy phylogenetic picture within the order Spathidiida. Because natural classification of spathidiids cannot be provided at the present state of knowledge, we suggest to keep the existing morphology-based generic classification, but stress that the large spathidiid genera are artificial collective groups. [ABSTRACT FROM AUTHOR]

The astomatous metaradiophryids are ciliates which live endosymbiotically in earthworms (Annelida, Lumbricidae). Their prominent hook apparatus is demonstrated in detail in light micrographs of living organisms as well as in scanning electron micrographs of Parducz-fixed cells. Since it was first observed, this structure has been interpreted as a 'holdfast' organelle preventing ciliates from being expelled prematurely from the intestine of the worm along with its excrements. No active movement of the hook has been reported in earlier papers or in our recent studies. Nevertheless, a detailed description of different parts of the hook apparatus exists in older literature, including a hypothesis on how these elements interact with each other to function as a holdfast device - without any experimental evidence. The suspected mode of function of this structure is questioned and critically discussed. [ABSTRACT FROM AUTHOR]

A new hypotrichous ciliate, Apoterritricha lutea n. g., n. sp., was discovered in a sample of a terrestrial liverwort from Korea. Its morphology was studied using detailed in vivo observation and protargol impregnation. Its phylogenetic relationships were revealed by analyses of the 18S rRNA gene. This new taxon is characterized by a combination of the following traits: (i) ellipsoidal to narrowly ellipsoidal body with an average size of 230 × 85 μm; (ii) two macronuclear nodules and two to five micronuclei; (iii) golden yellow cortical granules, forming small groups along the microtubular appendages of cirri, adoral membranelles, and dorsal kineties; (iv) typically three frontal cirri, one buccal cirrus, four frontoventral cirri, seven midventral cirri, two pretransverse cirri, seven transverse cirri, ca. 38 left, and ca. 36 right marginal cirri; and (v) on average six dorsal kineties, three dorsomarginal kineties, and three caudal cirri. In molecular phylogenies, A. lutea clusters with strong support within a clade containing Afrokeronopsis aurea and several 'typical' oxytrichids having golden yellow to brown cortical granules. In this light we propose a hypothesis that is not unambiguously rejected by the present phylogenetic analyses, which shows how the Afrokeronopsis-like pattern could have evolved from a Rubrioxytricha-like ancestor via an Apoterritricha-like stage by cirri-multiplication. [ABSTRACT FROM AUTHOR]

The article presents research which focused on the impact of rainfall on the composition of the ciliate community found in the Prana River in southern Brazil. Topics covered include the predominance of hymenostomatids in the phytotelmata of tank bromeliads as well as the analysis of the changes in the population of the species in the dry season. Also mentioned is the importance of high precipitation volume to the population of the species.

This study has been initiated to show the reproductive potential and some methods of assessment of reproductive capacity in Ciliates. The reproductive capacity of unicellular organisms by binary division was determined depending on the age of the population. The reproduction of organisms was made "in vitro" because the observation of some particularities of the Ciliates is impossible to estimate in natural conditions which are complex and vary permanently. The research tried to determine the longevity of Infusoria, the number of bunary division, and the number of generations after the sexuated multiplication process. It was based on the ciliate protozoa model. The basic culture used in investigation is Paramecium caudatum. [ABSTRACT FROM AUTHOR]

A novel parasitic ciliate Fusiforma themisticola n. gen., n. sp. was discovered infecting 4.4% of the hyperiid amphipod Themisto libellula. Ciliates were isolated from a formaldehyde-fixed whole amphipod and the DNA was extracted for amplification of the small subunit (SSU) rRNA gene. Sequence and phylogenetic analyses showed unambiguously that this ciliate is an apostome and about 2% divergent from the krill-infesting apostome species assigned to the genus Pseudocollinia. Protargol silver impregnation showed a highly unusual infraciliature for an apostome. There are typically 8 (6-9) bipolar somatic kineties covering the banana-shaped body. The anterior end of the oral cavity begins about 1/3 of the body length from the anterior end and is composed of an inpocketing that is lined on its anterior and left wall with an oral field of densely packed ciliated kinetosomes. Stomatogenesis begins with some dedifferentiation of the parental oral field and elongation of its paroral and oral kineties. A new oral field develops midventrally and the paroral and oral kineties break to form the oral apparatus of the opisthe, which completes development by additional kinetosomal proliferation and migration of the paroral. This morphology is novel among apostomes and justifies the establishment of a new genus and species. [Copyright &y& Elsevier]

Abstract: 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. [Copyright &y& Elsevier]

Abstract: The morphology and infraciliature of a new ciliate, Aspidisca hongkongensis spec. nov., a large marine form isolated from the coastal waters near Hong Kong, were investigated. It differs from the congeners by the combination of cell size (about 90×60μm in vivo), 9–11 conspicuous dorsal ridges, one fine and seven strong frontoventral cirri, six membranelles in anterior portion of adoral zone, and 17–23 membranelles in posterior portion of adoral zone. The comparison with similar congeners clearly supports the distinction of this new species based on morphological and small subunit (SSU) rRNA gene sequence studies. The SSU rRNA gene sequence similarity within the genus is about 75.3–92.1% which indicates that this is a distinct form. Phylogenetic trees based on SSU rRNA gene information show that A. hongkongensis groups with A. leptaspis. [Copyright &y& Elsevier]

Abstract: Species composition and distribution of large intestinal ciliates was investigated in the feces from 13 Cypriot wild donkeys, free-living in the Karpaz national park, Northern Cyprus. We identified 16 ciliate genera and 22 species. This is the first report on intestinal ciliates in Cypriot wild donkeys, and no endemic species were observed. The genus Cycloposthium occurred in all animals. The mean number of ciliates was 3.0±2.5×104 cellsml−1 of feces and the mean number of ciliate species per host was 6.5±4.8. Characteristics of the wild donkey ciliates was almost identical to those reported in other equids from various regions around the world. We thus conclude that there is no pronounced geographic variation in the intestinal ciliate fauna of equids. [Copyright &y& Elsevier]

Endosymbiotic bacteria were identified in the parasitic ciliate Ichthyophthirius multifiliis, a common pathogen of freshwater fish. PCR amplification of DNA prepared from two isolates of I. multifiliis, using primers that bind conserved sequences in bacterial 16S rRNA genes, generated an 1,460-bp DNA product, which was cloned and sequenced. Sequence analysis demonstrated that 16S rRNA gene sequences from three classes of bacteria were present in the PCR product. These included Alphaproteobacteria (Rickettsiales), Sphingobacteria, and Flavobacterium columnare. DAPI (4′,6-diamidino-2-phenylindole) staining showed endosymbionts dispersed throughout the cytoplasm of trophonts and, in most, but not all theronts. Endosymbionts were observed by transmission electron microscopy in the cytoplasm, surrounded by a prominent, electron-translucent halo characteristic of Rickettsia. Fluorescence in situ hybridization demonstrated that bacteria from the Rickettsiales and Sphingobacteriales classes are endosymbionts of I. multifiliis, found in the cytoplasm, but not in the macronucleus or micronucleus. In contrast, F. columnare was not detected by fluorescence in situ hybridization. It likely adheres to I. multifiliis through association with cilia. The role that endosymbiotic bacteria play in the life history of I. multifiliis is not known. [ABSTRACT FROM AUTHOR]

The morphology and infraciliature of Orthodonella sinica n. sp. and Apokeronopsis wrighti n. sp., isolated from the coastal water off Hong Kong, were investigated in living and stained specimens. Orthodonella sinica n. sp. is diagnosed as: a marine Orthodonella 150–310 × 40–80 μm in vivo; with a dominant beak-like projection at the anterior end; about 70 somatic kineties; 84–126 dikinetids in the synhymenium; one contractile vacuole in the posterior one-fourth of cell, near the left margin; one conspicuous dorsal suture. Apokeronopsis wrighti n. sp. is diagnosed as: an Apokeronopsis about 150–230 × 35–55 μm in vivo; dark-reddish blood-cell-shaped cortical granules grouped in three rows on the ventral side and two rows on the dorsal side; 23–35 cirri in the right mid-ventral rows (MVR) and 23–32 cirri in the left MVR; six to eight buccal, two frontoterminal, 30–42 left marginal, and 32–43 right marginal cirri; 21–30 transverse cirri extending anteriorly beyond the level of mid-body; consistently three dorsal kineties. The separation of A. wrighti n. sp. and its highly similar congeners Apokeronopsis crassa and Apokeronopsis bergeri was supported by comparison of their SSrRNA gene sequences. [ABSTRACT FROM AUTHOR]

Two marine peritrich ciliates, Vorticella fusca Precht (1935) and Vorticella parapulchella n. sp. were discovered in the littoral zone of Qingdao, northern China. Their morphology, infraciliature, and silverline system were described using live observation and silver impregnation. The poorly known species V. fusca is redescribed, adding information about the oral infraciliature and pellicular morphology. Vorticella parapulchella n. sp. is superficially similar to Vorticella pulchella Sommer (1951) but is distinguished from it by being markedly smaller and having much more widely spaced pellicular ridges. The infundibular infraciliature of V. parapulchella is extremely unusual in having infundibular polykinety 3 reduced to two rows, one of which has almost disappeared. [ABSTRACT FROM AUTHOR]

The morphology, infraciliature and morphogenesis of the marine hypotrichous ciliate, Thigmokeronopsis rubra sp. nov., collected from the coastal waters off Qingdao (Tsingtao), China, were studied in vivo and following protargol impregnation. Compared with the known Thigmokeronopsis species, T. rubra is distinguished by its elongated fusiform body shape, in vivo about 140-200 µm long with two kinds of granules, pale yellow-green and red, respectively; 11-16 frontal, two frontoterminal, one buccal and ca seven transverse cirri; usually 7-11 left postoral ventral files; two mid-ventral rows comprising a total of ca 51 cirri; 30-49 left and 28-45 right marginal cirri; three complete dorsal kineties. The morphogenetic process can be summarized as follows: (1) an anarchic field originates independently between the left mid-ventral cirri and the left postoral ventral files and generates the opisthe's adoral membranelles, undulating membranes, frontoventral and transverse cirri; (2) the proter's oral primordium originates apokinetally to the left of the undulating membranes and develops on the bottom and right walls of the buccal cavity producing the new undulating membranes and adoral membranelles; (3) the fronto-ventral transverse anlage (FVT-anlage) originates independently near the anterior left mid-ventral cirri in the proter; (4) the marginal rows and dorsal kineties originate de novo in both dividers; (5) the old structures do not participate in the formation of the new ones and are eventually replaced; (6) the macronuclear nodules fuse completely forming a single branched mass prior to division. [ABSTRACT FROM AUTHOR]