Agolohymena aspidocauda nov. gen., nov. spec., a histophagous freshwater tetrahymenid ciliate in the family Deltopylidae (Ciliophora, Hymenostomatia), from Idaho (northwest U.S.A.): Morphology, ontogenesis and molecular phylogeny (original) (raw)
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European Journal of Protistology, 2013
The morphology, ontogeny and molecular phylogeny of Apobakuella fusca gen. n., sp. n. and Parabistichella variabilis gen. n., sp. n., from south China were investigated. Apobakuella fusca, brown colored, demonstrates bakuellid-like infraciliature, and a similar ontogenesis as the genus Bakuella. It is argued, however, that this species represents a novel genus, Apobakuella, which is characterized by two or more marginal rows on the right, several buccal and parabuccal cirri, and lack of frontoterminal and caudal cirri. Phylogenetic analysis based on SSU rRNA gene sequences supports the close relationship of Apobakuella with Neobakuella and Diaxonella within the core Urostylida. By contrast, Parabistichella variabilis has a dominant frontoventral row, few midventral pairs, a long midventral row, and one marginal row on each side. Its morphogenesis exhibits: (1) partial reorganization of the parental adoral membranelles; (2) over six frontoventral-transverse cirri anlagen; (3) intrakinetal development of the midventral row; and (4) very likely, formation of the frontoventral row from the midventral row anlage. Both the morphological characteristics and the SSU rRNA gene sequences suggest that it is incertae sedis among the basal hypotrichs. Further investigation of key taxa with additional molecular markers is required to reveal a better understanding on the phylogeny of Parabistichella.
European Journal of Protistology, 2011
Dileptid and tracheliid ciliates have been traditionally classified within the subclass Haptoria of the class Litostomatea. However, their phylogenetic position among haptorians has been controversial and indicated that they may play a key role in understanding litostomatean evolution. In order to reconstruct the evolutionary history of dileptids and tracheliids, and to unravel their affinity to other haptorians, we have used a cladistic approach based on morphological evidence and a phylogenetic approach based on 18S rRNA gene sequences, including eight new ones. The molecular trees demonstrate that dileptids and tracheliids represent a separate subclass, Rhynchostomatia, that is sister to the subclasses Haptoria and Trichostomatia. The Rhynchostomatia are characterized by a ventrally located oral opening at the base of a proboscis that carries a complex oral ciliature. We have recognized two orders within Rhynchostomatia. The new order Tracheliida is monotypic, while the order Dileptida comprises two families: the new, typically bimacronucleate family Dimacrocaryonidae and the multimacronucleate family Dileptidae. The Haptoria evolved from the last common ancestor of the Litostomatea by polarization of the body, the oral opening locating more or less apically and the oral ciliature simplifying. The Trichostomatia originated from a microaerophylic haptorian by further simplification of the oral ciliature, possibly due to an endosymbiotic lifestyle. © 2011 Elsevier GmbH. ⁎ Corresponding author. Tel.: +421 2 602 96 256; fax: +421 2 602 96 333. vdacny@fns.uniba.sk.
The Journal of Protozoology, 1987
The morphology and the morphogenesis of the freshwater hypotrich ciliate Onychodromus quadricornutus n. sp. have been investigated using living organisms, protargol impregnation, and scanning electron microscopy. Some preliminary and supplementary results about the morphogenesis of 0. grandis and Laurentiella acuminata are included. The new species is unique among all described hypotrichs in having four dorsal horns, whose function is unknown. In addition, 0. quadricornutus is probably the most voluminous hypotrich ciliate known (2 x 10b-5 x lo6 pm3). Its morphogenetic pattern resembles the oxytrichids 0. grandis and L. acuminata. The strongest apomorphic character, which unites these three species, is probably the multiple fragmentation of the dorsal primordia during morphogenesis. This fragmentation causes the characteristic high number and more or Iess irregular distribution of the dorsal kineties in the non-dividing individuals. YPOTRICHOUS ciliates have been well known for a long H time and were carefully studied by many authors; however, their classification remains controversial to date (5). The new species described is unique among all known hypotrichous ciliates in having horns and presents new data that may contribute to a deeper understanding of systematics and evolution of the family Oxytrichidae in the order Hypotrichida.
Zoological Journal of the Linnean Society, 2016
The morphology and phylogeny of three heterotrich ciliates, Anigsteinia clarissima (Anigstein, 1912) Isquith, 1968, Blepharisma penardi sp. nov., and Blepharisma undulans Stein, 1867, were investigated based on living morphology, infraciliature, and small subunit (SSU) rDNA sequence data. The new species B. penardi sp. nov. is recognized by the following combination of characters: size about 150-180 × 45-55 μm in vivo, cell colour variable from colourless to pale pink to dark brownish; peristome extending to middle of body; 36-63 adoral membranelles; 24-34 somatic kineties; single macronucleus; cortical granules tiny and colourless; freshwater habitat. Anigsteinia clarissima and B. undulans are both reported from China for the first time and are redescribed based on a combination of previous descriptions and new data from the Chinese populations. Phylogenetic analyses based on SSU rDNA sequence data show that B. penardi sp. nov. and B. undulans are both located within a clade comprising only congeners, thus supporting the monophyly of the genus Blepharisma. Anigsteinia clarissima clusters with its only congener forming a clade that is sister to the Spirostomum assemblage. Both the morphological and the molecular data support the placement of Anigsteinia in the family Spirostomidae.
Coniculostomum bimarginata n. sp., a new hypotrich ciliate: Description and systematic relationships
European Journal of Protistology, 1994
The hypotrich ciliate Coniculostomum bimarginata n. sp. is characterized by an average size of 167.3 [lm X 84.1 urn, 18 cirri in the frontal ciliature, 2 rows of right marginal cirri (RMC), a single row of left marginal cirri, 4 dorsal kineties, and 3-4 dorsomarginal rows (DMs). During division only one RMC row and two DM rows are produced; additional RMC and DM rows are the persistent parental ciliature that is distributed to the two daughter cells.
Zoological Journal of the Linnean Society, 2016
The morphology and phylogeny of three heterotrich ciliates, Anigsteinia clarissima (Anigstein, 1912) Isquith, 1968, Blepharisma penardi sp. nov., and Blepharisma undulans Stein, 1867, were investigated based on living morphology, infraciliature, and small subunit (SSU) rDNA sequence data. The new species B. penardi sp. nov. is recognized by the following combination of characters: size about 150-180 × 45-55 μm in vivo, cell colour variable from colourless to pale pink to dark brownish; peristome extending to middle of body; 36-63 adoral membranelles; 24-34 somatic kineties; single macronucleus; cortical granules tiny and colourless; freshwater habitat. Anigsteinia clarissima and B. undulans are both reported from China for the first time and are redescribed based on a combination of previous descriptions and new data from the Chinese populations. Phylogenetic analyses based on SSU rDNA sequence data show that B. penardi sp. nov. and B. undulans are both located within a clade comprising only congeners, thus supporting the monophyly of the genus Blepharisma. Anigsteinia clarissima clusters with its only congener forming a clade that is sister to the Spirostomum assemblage. Both the morphological and the molecular data support the placement of Anigsteinia in the family Spirostomidae.
Molecular Phylogeny of the Cyrtophorid Ciliates (Protozoa, Ciliophora, Phyllopharyngea)
2012
Evolutionary relationships of cyrtophorian ciliates are poorly known because molecular data of most groups within this subclass are lacking. In the present work, the SS rRNA genes belonging to 17 genera, 7 families of Cyrtophoria were sequenced and phylogenetic trees were constructed to assess their inter-generic relationships. The results indicated: (1) the assignment of cyrtophorians into two orders is consistently confirmed in all topologies; (2) the order Dysteriida is an outlined monophyletic assemblage while Chlamydodontida is paraphyletic with three separate monophyletic families; (3) Microxysma, which is currently assigned within the family Hartmannulidae, should be transferred to the family Dysteriidae; (4) the systematic position of Plesiotrichopidae remains unclear, yet the two genera that were placed in this family before, Pithites and Trochochilodon, should be transferred to Chlamydodontida; (5) a new family, Pithitidae n. fam., based on the type genus Pithites was suggested; and (6) the sequence of Isochona sp., the only available data of Chonotrichia so far, is probably from a misidentified species. In addition, three group I introns of SS rRNA gene were discovered in Aegyriana oliva, among which Aol.S516 is the first IE group intron reported in ciliates.
Zoological Journal of the Linnean Society, 2021
Hypotrichs comprise a highly differentiated and diversified group of ciliates with an evolutionary history characterized by an exceptional number of convergences and reversions. A new hypotrich ciliate from a freshwater fishpond is investigated based on morphological, morphogenetic and molecular data. The phylogenetic analyses reveal that the new species is closely related to Simplicitergida despite the absence of zigzag-patterned midventral cirral pairs, a common feature of simplicitergids. The phylogenetic position of this atypical simplicitergid species is strongly supported by the conserved features of dorsal ciliature and nuclear apparatus, which are probably more informative than cirral patterns for higher-rank classification. The close phylogenetic relationships among those Simplicitergida with varied cirral patterns could be explained by evolutionary convergences and reversions. The new species is recognized mainly by three frontoventral rows, several short midventral rows, ...
2012
. Morphology and phylogeny of a new woodruffiid ciliate, Etoschophrya inornata sp. n. (Ciliophora, Colpodea, Platyophryida), with an account on evolution of platyophryids. -Zoologica Scripta, 00, 000-000. We studied the morphology, morphometry, resting cysts and molecular phylogeny of a new woodruffiid ciliate, Etoschophrya inornata, from ephemeral puddles and two lacustrine habitats in Idaho, North-west USA. Up to now, the genus Etoschophrya has included a single species, Etoschophrya oscillatoriophaga, from which our new form is distinguished by (i) the absence of interkinetal cortical granules and, consequently, the absence of extrusible red material in methyl green-pyronin stains, (ii) usually ‡5 adoral membranelles vs. usually four, (iii) greater length and length ⁄ width ratio, (iv) prominent cortical furrows vs. inconspicuous and (v) adaptation to non-saline semi-terrestrial and lacustrine habitats in the Nearctic vs. highly saline alkaline Afrotropic soil habitats. Resting cysts have two distinct membranes and a thick hyaline mucous pericyst layer. However, only one membrane persists in older cysts. Like its congener, Etoschophrya inornata feeds exclusively on filamentous cyanobacteria. The 18S rRNA gene sequence places this species in a strongly supported clade with Kuklikophrya ougandae basal to the other platyophryids. We include a morphologic cladistic analysis of platyophryid ciliates and present a hypothetical scenario for the evolution of the platyophryid oral structures.
Journal of Eukaryotic Microbiology, 2009
ABSTRACT. Based on its characteristic oral apparatus, the ciliate subclass Peritrichia has long been recognized as a monophyletic assemblage composed of the orders Mobilida and Sessilida. Following the application of molecular methods, the monophyly of Peritrichia has recently been questioned. We investigated the phylogenetic relationships of the peritrichous ciliates based on four further complete small subunit ribosomal RNA sequences of mobilids, namely Urceolaria urechi, Trichodina meretricis, Trichodina sinonovaculae, and Trichodina ruditapicis. In all phylogenetic trees, the mobilids never clustered with the sessilids, but instead formed a monophyletic assemblage related to the peniculines. By contrast, the sessilids formed a sister clade with the hymenostomes at a terminal position within the Oligohymenophorea. We therefore formally separate the mobilids from the sessilids (Peritrichia sensu stricto) and establish a new subclass, Mobilia Kahl, 1933, which contains the order Mobilida Kahl, 1933. We argue that the oral apparatus in the mobilians and sessilid peritrichs is a homoplasy, probably due to convergent evolution driven by their similar life-styles and feeding strategies. Morphologically, the mobilians are distinguished from all other oligohymenophoreans by the presence of the adhesive disc, this character being a synapomorphy for the Mobilia.