scholarly journals Cell-division pattern and phylogenetic position of a new ciliate genus Parasincirra n. g. (Protista, Ciliophora, Hypotrichia), with report of a new soil species, P. sinica n. sp. found from northwest China

2020 ◽  
Author(s):  
Chen Shao ◽  
Jiyang Ma ◽  
Yan Zhao ◽  
Tengyue Zhang ◽  
Khaled A.S. Al-Rasheid ◽  
...  

Abstract Background: Ciliated species, unicellular eukaryotes, are extremely diverse and occupy a very broad spectrum of ecological niches. Even though there is a growing recognition that enormous ciliates associates with key ecosystem processes in different niches, their diversity is not well understood. One reason is that ciliates are very tiny and may often be overlooked in routine biodiversity survey. Furthermore, the morphological and genetic diversity of ciliates per se is vast and dwarfs that among other multicellular eukaryotes. Here, we present the study of a new stichotrichid ciliate, Parasincirra sinica n. g., n. sp. based on classical living morphology, infraciliature, ontogenesis analyses and a comprehensive phylogenetic study, and enhance understanding of ciliates diversity in sludge soil.Results: This new, monotypic genus is defined by having a bipartite adoral zone of membranelles, three frontal cirri, an amphisiellid median cirral row about as long as, or slightly longer than, the adoral zone, one short frontoventral cirral row, cirrus III/2 and transverse cirri present, buccal cirrus and caudal cirri absent, one right and one left marginal row and three dorsal kineties. The main morphogenetic features of the new taxon are: (1) five frontoventral-transverse cirral anlagen (excluding undulating membranes anlage) are formed in primary mode; (2) the amphisiellid median cirral row is formed by anlagen V and VI, while the frontoventral row is generated from anlage IV; (3) cirral streaks IV to VI generate one transverse cirrus each; (4) frontoventral-transverse cirral anlage II generates one or two cirri, while the posterior one will be absorbed in late stages, that is, no buccal cirrus is formed; (5) the posterior part of the parental adoral zone of membranelles is renewed; (6) dorsal morphogenesis follows a typical Gonostomum-pattern; and (7) the macronuclear nodules fuse to form a single mass. Based on the SSU rDNA information, analyses of the phylogenetic relationship inferred from Bayesian inference and maximum likelihood analyses were unable to outline the exact position of this new form among some other species of related genera which are generally assigned in the family Amphisiellida. The morphological/ morphogenetical differences between the new genus/species and Uroleptoides/ Parabistichella, as well as other amphisiellids, clearly support the validity of the establishment of this new genus Parasincirra.

2019 ◽  
Author(s):  
Jiyang Ma ◽  
Yan Zhao ◽  
Tengyue Zhang ◽  
Chen Shao ◽  
Khaled A.S. Al-Rasheid ◽  
...  

Abstract Background Ciliated species, unicellular eukaryotes, are extremely diverse and occupy a very broad spectrum of ecological niches. Even though there is a growing recognition that enormous ciliates associates with key ecosystem processes in different niches, their diversity is not well understood. One reason is that ciliates are very tiny and may often be overlooked in routine biodiversity survey. Furthermore, the morphological and genetic diversity of ciliates per se is vast and dwarfs that among other multicellular eukaryotes. A new stichotrichid ciliate, Parasincirra sinica n. g., n. sp. is based on classical living morphology, infraciliature, ontogenesis analyses and a comprehensive phylogenetic studies, and enhance understanding of ciliates diversity in sludge soil.Results This new, monotypic genus is defined by having a bipartite adoral zone of membranelles, three frontal cirri, an amphisiellid median cirral row about as long as, or slightly longer than, the adoral zone, one short frontoventral cirral row, cirrus III/2 and transverse cirri present, buccal cirrus and caudal cirri absent, one right and one left marginal row and three dorsal kineties. The morphogenetic features are: (1) five frontoventral-transverse cirral anlagen (excluding undulating membranes anlage) are formed in primary mode; (2) the amphisiellid median cirral row is formed by anlagen V and VI, while the frontoventral row is generated from anlage IV; (3) cirral streaks IV to VI generate one transverse cirrus each; (4) frontoventral-transverse cirral anlage II generates one or two cirri, while the posterior one will be absorbed in late stages, that is, no buccal cirrus is formed; (5) the posterior part of the parental adoral zone of membranelles is renewed; (6) dorsal morphogenesis follows a typical Gonostomum -pattern; and (7) the macronuclear nodules fuse to form a single mass. Based on the SSU rDNA information, analyses of the phylogenetic relationship inferred from Bayesian inference and maximum likelihood analyses were unable to outline the exact position of this new form among some other species of related genera which are generally assigned in the family Amphisiellida. The morphological/ morphogenetical differences between the new genus/species and other amphisiellids, clearly support the validity of the establishment of this new genus Parasincirra .


2019 ◽  
Author(s):  
Jiyang Ma ◽  
Yan Zhao ◽  
Tengyue Zhang ◽  
Chen Shao ◽  
Khaled A.S. Al-Rasheid ◽  
...  

Abstract Ciliated species, unicellular eukaryotes, are extremely diverse and occupy a very broad spectrum of ecological niches. Even though there is a growing recognition that enormous ciliates associates with key ecosystem processes in different niches, their diversity is not well understood. One reason is that ciliates are very tiny and may often be overlooked in routine biodiversity survey. Furthermore, the morphological and genetic diversity of ciliates per se is vast and dwarfs that among other multicellular eukaryotes. Here, we present the study of a new stichotrichid ciliate, Parasincirra sinica n. g., n. sp. based on classical living morphology, infraciliature, ontogenesis analyses and a comprehensive phylogenetic study, and enhance understanding of ciliates diversity in sludge soil. This new, monotypic genus is defined by having a bipartite adoral zone of membranelles, three frontal cirri, an amphisiellid median cirral row about as long as, or slightly longer than, the adoral zone, one short frontoventral cirral row, cirrus III/2 and transverse cirri present, buccal cirrus and caudal cirri absent, three dorsal kineties. The main morphogenetic features are: (1) five frontoventral-transverse cirral anlagen (excluding undulating membranes anlage) are formed in primary mode; (2) the amphisiellid median cirral row is formed by anlagen V and VI, while the frontoventral row is generated from anlage IV; (3) cirral streaks IV to VI generate one transverse cirrus each; (4) frontoventral-transverse cirral anlage II generates one or two cirri, while the posterior one will be absorbed in late stages, that is, no buccal cirrus is formed; (5) the posterior part of the parental adoral zone of membranelles is renewed; (6) dorsal morphogenesis follows a typical Gonostomum -pattern. Based on the SSU rDNA information, analyses of the phylogenetic relationship inferred from Bayesian inference and maximum likelihood analyses were unable to outline the exact position of this new form among some other species of related genera which are generally assigned in the family Amphisiellida . The morphological/ morphogenetical differences between the new genus/species and Uroleptoides / Parabistichella , as well as other amphisiellids, clearly support the validity of the establishment of this new genus Parasincirra .


2020 ◽  
Author(s):  
Chen Shao ◽  
Jiyang Ma ◽  
Yan Zhao ◽  
Tengyue Zhang ◽  
Khaled A.S. Al-Rasheid ◽  
...  

Abstract Background: Ciliated protists, a huge assemblage of unicellular eukaryotes, are extremely diverse and play important roles in ecosystem in almost all kinds of habitats. Even though there is a growing recognition that those organisms associate with many ecological or environmental processes, their biodiversity, due to many reasons, is poorly understood and many biotopes (e.g. the soil in desert area in Asia) remain largely unknown or unconsidered. Here we document an undescribed form found in sludge soil in a halt-desert inland in China and the taxonomic/ morphogenetic surveys indicate that it represents a new genus and new species, Parasincirra sinica n. g., n. sp. which is supported also by molecular data.Results: This new, monotypic genus Parasincirra n. g. is defined by having three frontal cirri, an amphisiellid median cirral row about as long as the adoral zone, one short frontoventral cirral row, cirrus III/2 and transverse cirri present, buccal and caudal cirri absent, one right and one left marginal row and three dorsal kineties. The main morphogenetic features of the new taxon are: (1) frontoventral-transverse cirral anlagen II to VI are formed in primary mode; (2) the amphisiellid median cirral row is formed by anlagen V and VI, while the frontoventral row is generated from anlage IV; (3) cirral streaks IV to VI generate one transverse cirrus each; (4) frontoventral-transverse cirral anlage II generates one or two cirri, while the posterior one will be absorbed in late stages, that is, no buccal cirrus is formed; (5) the posterior part of the parental adoral zone of membranelles is renewed; (6) dorsal morphogenesis follows a typical Gonostomum-pattern; and (7) the macronuclear nodules fuse to form a single mass. Based on the SSU rDNA information, analyses of the phylogenetic relationship inferred from Bayesian inference and maximum likelihood analyses were unable to outline the exact position of this new form among some other species of related genera which are generally assigned in the family Amphisiellidae Jankowski, 1979. The morphological/ morphogenetical differences between the new genus/species and Uroleptoides Wenzel, 1953/ Parabistichella Jiang et al., 2013, as well as other amphisiellids, clearly support the validity of the establishment of this new genus Parasincirra.


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Jiyang Ma ◽  
Yan Zhao ◽  
Tengyue Zhang ◽  
Chen Shao ◽  
Khaled A. S. Al-Rasheid ◽  
...  

Abstract Background Ciliated protists, a huge assemblage of unicellular eukaryotes, are extremely diverse and play important ecological roles in most habitats where there is sufficient moisture for their survivals. Even though there is a growing recognition that these organisms are associated with many ecological or environmental processes, their biodiversity is poorly understood and many biotopes (e.g. soils in desert areas of Asia) remain largely unknown. Here we document an undescribed form found in sludge soil in a halt-desert inland of China. Investigations of its morphology, morphogenesis and molecular phylogeny indicate that it represents a new genus and new species, Parasincirra sinica n. g., n. sp. Results The new, monotypic genus Parasincirra n. g. is defined by having three frontal cirri, an amphisiellid median cirral row about the same length as the adoral zone, one short frontoventral cirral row, cirrus III/2 and transverse cirri present, buccal and caudal cirri absent, one right and one left marginal row and three dorsal kineties. The main morphogenetic features of the new taxon are: (1) frontoventral-transverse cirral anlagen II to VI are formed in a primary mode; (2) the amphisiellid median cirral row is formed by anlagen V and VI, while the frontoventral row is generated from anlage IV; (3) cirral streaks IV to VI generate one transverse cirrus each; (4) frontoventral-transverse cirral anlage II generates one or two cirri, although the posterior one (when formed) will be absorbed in late stages, that is, no buccal cirrus is formed; (5) the posterior part of the parental adoral zone of membranelles is renewed; (6) dorsal morphogenesis follows a typical Gonostomum-pattern; and (7) the macronuclear nodules fuse to form a single mass. The investigation of its molecular phylogeny inferred from Bayesian inference and Maximum likelihood analyses based on small subunit ribosomal DNA (SSU rDNA) sequence data, failed to reveal its exact systematic position, although species of related genera are generally assigned to the family Amphisiellidae Jankowski, 1979. Morphological and morphogenetic differences between the new taxon and Uroleptoides Wenzel, 1953, Parabistichella Jiang et al., 2013, and other amphisiellids clearly support the validity of Parasincirra as a new genus. The monophyly of the family Amphisiellidae is rejected by the AU test in this study. Conclusions The critical character of the family Amphisiellidae, i.e., the amphisiellid median cirral row, might result from convergent evolution in different taxa. Amphisiellidae are not monophyletic.


2005 ◽  
Vol 3 (4) ◽  
pp. 489-498 ◽  
Author(s):  
Alexandre C. Ribeiro ◽  
Murilo Carvalho ◽  
Alex L. A. Melo

Otothyropsis marapoama, a new genus and species, is described based on specimens recently collected in a headwater stream of the middle stretch of the rio Tietê, a river from the upper rio Paraná basin in southeastern Brazil. The new taxon belongs to a clade also encompassing the genera Schizolecis, Otothyris and Pseudotothyris. Otothyropsis marapoama is hypothesized to be the sister-group of Pseudotothyris and Otothyris based mainly on the presence of several derived characters of the swimbladder capsule and associated bones. Several paedomorphic characters shared by Pseudotothyris and Otothyris and their significance for the phylogenetic position of the new genus are discussed.


2017 ◽  
Author(s):  
Gabriel S. Ferreira ◽  
Fabiano Vidoi Iori ◽  
Guilherme Hermanson ◽  
Max C. Langer

A high diversity of land vertebrates is known from the Late Cretaceous deposits of the Bauru Basin, Brazil, including at least five turtle taxa, all belonging tothe cladePodocnemidoidae. Some of the richest fossil sites of this basin are in the area of Monte Alto, which yielded several squamate, dinosaur, and crocodyliform taxa. Yet, the single turtle reported so far from this area was only briefly described. Here, we further describe that specimen, a complete but very crushed shell, as well as a partial skull, both found in outcrops of the Adamantina Formation. Comparison of the shell to other podocnemidoid taxa reveals its affinities to Roxochelys wanderleyi, a turtle originally described from that same stratigraphic unit. The comparative description of the skull and its inclusion in a phylogenetic study, supports the proposal of a new taxon representing a lineage (Peiropemydodda) so far known only from the Marília Formation of the Bauru Basin and the early Paleocene of Bolivia. The digitally reconstructed endocast and inner ear of the new taxon were also described, as not previously done fora fossil pleurodire.


2006 ◽  
Vol 143 (5) ◽  
pp. 723-735 ◽  
Author(s):  
O. ERIK TETLIE

Eurypterids from the Welsh Borderlands of England are redescribed from most available material. Hughmilleria banksii is here interpreted to represent a new genus. The poorly known Hughmilleria (?) acuminata (Salter, 1859a) is considered a junior synonym of H. banksii. Furthermore, Slimonia? stylops is suspected to be a junior synonym of Salteropterus abbreviatus, although they are not formally synonymized as the location of the only known specimen of S.? stylops is unknown. Morphological differences in carapace shape, eye position, walking leg, genital appendage and telson in H. banksii are noted compared to previous descriptions. A prosomal appendage earlier assigned to H. banksii is here assigned with caution to S. abbreviatus and the reported ‘segments’ in the posterior part of the telson of S. abbreviatus are shown to be cracks. The phylogenetic position of the new genus is inferred to lie between the Hughmilleria and the Slimonia/Salteropterus clades.


2008 ◽  
Vol 6 (4) ◽  
pp. 663-678 ◽  
Author(s):  
Cristina M. Bührnheim ◽  
Tiago P. Carvalho ◽  
Luiz R. Malabarba ◽  
Stanley H. Weitzman

Amazonspinther dalmata, a new miniature characid from the streams of rio Purus and rio Madeira, right bank tributaries of the rio Amazonas, is described as a new genus and species of the subfamily Cheirodontinae. The unique characters of the new genus and species are the three remarkable black blotches on the base of the dorsal, anal, and caudal fins, the anteriormost proximal radial of the anal fin with an anteriorly extended lamina entering the abdominal cavity, and the extremely elongate caudal peduncle. The reduced number of ventral procurrent caudal-fin rays (7-9), and the hemal spines of only posterior one, two, or sometimes three caudal vertebrae directly articulating with the ventral procurrent caudal-fin rays further diagnoses the new taxon from remaining genera of the tribe Cheirodontini. The results of a phylogenetic analysis strongly support a close relationship between A. dalmata and Spintherobolus in the tribe Cheirodontini on the basis of fifteen unambiguous synapomorphies. Ten of these characters, previously hypothesized as exclusive synapomorphies for Spintherobolus, were now also identified in Amazonspinther, such as the pattern of exposed neuromasts on the head, the presence of a second pseudotympanum anterior to the first pleural rib, and the nearly discoidal coracoid bone. A discussion about the phylogenetic position of the closely related fossil †Megacheirodon to Spintherobolus and Amazonspinther is also provided. Convergent characters shared between Amazonspinther and the characid Priocharax are discussed in relation to miniaturization. Biogeographical implications of the diversification of Amazonspinther, Spintherobolus, and Megacheirodon lineages are discussed.


2020 ◽  
Author(s):  
Zhao Lyu ◽  
Jingbao Li ◽  
Yurui Wang ◽  
Jiyang Ma ◽  
Chen Shao

Abstract Background: Hypotrichous ciliates are showing extremely morphological diverse and complicated morphogenesis. However, many hypotrichs are still unknown/poorly-known and need to be explored. Recently, Foissner (2016) reassigned the species in Bistichella and Parabistichella. Due to lack of morphological and morphogenetic information, some problems were overlooked. In present work, a new species, Bistichella granulifera n. sp., was found in northern China. Based on its infraciliature, ontogenesis analyses and phylogenetic study, the phylogenetic position of Bistichella was discussed.Results: Bistichella granulifera n. sp. was characterized by having elongated oval body, two macronuclear nodules, cortical granules present, three frontal and three or four buccal cirri, three frontal rows with seven to ten cirri, usually two frontoventral rows with the left one usually terminates at 90% down length of body and no breaks in the right one. The main morphogenetic features of the novel species were as follows: (1) the posterior part of the old adoral membranelles is renewed; (2) frontoventral-transverse cirral anlagen III to V each form a frontal row, and anlagen VI to n each produce a frontoventral row; (3) both marginal rows and dorsal kineties develop intrakinetally; (4) the macronuclear nodules fuse to form a single mass. The gene sequence of Bistichella was investigated for the first time. Phylogenetic analyses based on the SSU rDNA sequences showed that the Bistichella groups with the non-dorsomarginalian hypotrichs.Conclusions: Morphology, morphogenesis and phylogenetic position of Bistichella granulifera n. sp., was investigated. Each frontoventral row originates from one anlage and only three bipolar dorsal kineties are present in the new species, which means it should belong to non-Dorsomarginalia rather than Amphisiellidae. Even though Bistichella has a close relationship with amphisiellids, due to the limited gene sequence, the phylogenetic position of Bistichella needs more data to be fully understood.


Author(s):  
Noureddine KHALLOUFI ◽  
Mustapha BÉJAOUI ◽  
Diana DELICADO

The species richness of the aquatic (non-marine) gastropod family Hydrobiidae Stimpson, 1865 reaches its peak in the European region partly because other areas, such as North Africa, remain to be extensively surveyed. Most of the hydrobiid species described in North Africa have been ascribed to the subfamilies Pseudamnicolinae, Hydrobiinae and the genus Mercuria. Little is known about the presence of other hydrobiid subfamilies. This study examines several specimens of gastropods collected from two springs in Tunisia. Based on a comprehensive literature review and rigorous anatomical and molecular comparisons with known species from North Africa, Europe and Asia Minor of similar morphology, we here describe a new genus, Bullaregia gen. nov., and new species Bullaregia tunisiensis gen. et sp. nov. Although the shell shape of this Tunisian species resembles that of European hydrobiid genera such as Belgrandiella, it differs in other anatomical structures (i.e., penis with a glandular strap-like lobe, and two seminal receptacles, SR1 pedunculate, SR2 sessile and less developed). Using maximum likelihood and Bayesian approaches, phylogenetic relationships inferred from mtCOI sequences point to an independent evolutionary lineage for this new taxon outside Belgrandiella and other known hydrobiid subfamilies.


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