scholarly journals Morphology, Morphogenesis, and Molecular Phylogeny of a New Freshwater Ciliate, Quadristicha subtropica n. sp. (Ciliophora, Hypotrichia)

2021 ◽  
Vol 12 ◽  
Author(s):  
Chen Shao ◽  
Qi Gao ◽  
Alan Warren ◽  
Jingyi Wang

The morphology and the regulation of cortical pattern associated with the cell size, division, and phylogenetic position of a new hypotrichous ciliate, Quadristicha subtropica n. sp. collected from a freshwater pond in southern China, were investigated. Quadristicha subtropica n. sp. is characterized as follows: size in vivo 60–115 μm × 25–45 μm; 19–21 adoral membranelles; buccal cirrus near anterior end of endoral and paroral; cirrus IV/3 at about level of buccal vertex; right marginal row begins ahead of buccal vertex; 11–16 right and 12–19 left marginal cirri; and dorsal cilia about 5 μm long. The basic morphogenetic process in Q. subtropica n. sp. is consistent with that of the type species, Quadristicha setigera. Phylogenetic analyses based on small subunit ribosomal DNA sequence data reveal that the systematic position of Q. subtropica n. sp. is rather unstable with low support values across the tree and the genus Quadristicha is not monophyletic.

2015 ◽  
Vol 65 (Pt_9) ◽  
pp. 3216-3225 ◽  
Author(s):  
Xiaoteng Lu ◽  
Chen Shao ◽  
Yuhe Yu ◽  
Alan Warren ◽  
Jie Huang

The oxytrichid species Pleurotricha curdsi (Shi et al., 2002) Gupta et al., 2003, isolated from a tributary of the Yangtze River in the Mudong district of Chongqing, southern China, was reinvestigated with emphasis on its morphology, morphogenesis and small-subunit (SSU) rDNA-based phylogeny. Compared with three previously described populations, the Mudong population of P. curdsi is characterized by its large body size, 170–295 × 65–110 μm in vivo, and by having a variable number of right marginal rows, either two or three. Likewise, the number of right marginal rows anlagen (RMA) is also variable, i.e. usually two, but sometimes several small extra anlagen that give rise to the formation of the third row, are present to the left of the RMAs. We posit that the Mudong population is an intermediate form between the three previously described populations. Phylogenetic analyses based on the SSU rDNA sequence data show that all populations of P. curdsi cluster with the type species of the genus, Pleurotricha lanceolata, in a clade nested within the Oxytrichidae.


Nematology ◽  
2003 ◽  
Vol 5 (5) ◽  
pp. 699-711 ◽  
Author(s):  
Peter Mullin ◽  
Timothy Harris ◽  
Thomas Powers

AbstractThe systematic position of Campydora Cobb, 1920, which possesses many unique morphological features, especially in pharyngeal structure and stomatal armature, has long been a matter of uncertainty with the 'position of the Campydorinae' (containing only Campydora) being questionable. A review of the morphology of C. demonstrans, the only nominal species of Campydora concluded that the species warranted placement as the sole member of a monotypic suborder, Campydorina, in the order Dorylaimida. Others placed Campydorina in the order Enoplida. We conducted phylogenetic analyses, using 18s small subunit ribosomal DNA sequences generated from a number of taxa in the subclasses Enoplia and Dorylaimia, to evaluate these competing hypotheses. Although precise taxonomic placement of the genus Campydora and the identity of its closest living relatives is in need of further investigation, our analyses, under maximum parsimony, distance, and maximum likelihood criteria, unambiguously indicate that Campydora shares a common, more recent, ancestry with genera such as Alaimus, Pontonema, Tripyla and Ironus (Enoplida), rather than with any members of Dorylaimida, Mononchida or Triplonchida.


2021 ◽  
Vol 12 ◽  
Author(s):  
Qi Gao ◽  
Chen Shao ◽  
Qiuyue Tang ◽  
Jingbao Li

The morphology and morphogenesis of Pseudosincirra longicirrata nov. gen. and nov. comb., isolated from southern China, were investigated with living observation and protargol staining. Our population is similar to the original population in living characteristics and ciliary patterns. The main determinable morphogenetic features of P. longicirrata nov. comb. are the presence of five frontoventral-transverse cirral anlagen (FVT-anlagen) and a dorsomarginal kinety anlage. According to the origin of FVT-anlagen IV and V in proter, it can be determined that P. longicirrata nov. comb. possesses two frontoventral rows and one right marginal row. Hence, a new genus, Pseudosincirra nov. gen., is proposed, and the diagnosis of P. longicirrata nov. comb. is improved. The new genus is diagnosed as follows: adoral zone of membranelles and undulating membranes is in a Gonostomum pattern; there are three enlarged frontal cirri, one buccal cirrus, and one parabuccal cirrus; postperistomial cirrus and transverse cirri are lacking; there are two more or less long frontoventral rows and one right and two or more left marginal rows; cirri within all rows very widely spaced; dorsal kinety pattern is of Urosomoida type, that is, three dorsal kineties and one dorsomarginal kinety; and caudal cirri are present. Phylogenetic analyses based on the small subunit ribosomal (SSU rDNA) sequence data indicate that P. longicirrata nov. comb. clusters with Deviata and Perisincirra. It is considered that Pseudosincirra nov. gen. and Perisincirra paucicirrata should be assigned to the family Deviatidae; fine cirri, and cirri within all rows being relatively widely spaced, should be considered as plesiomorphies of Deviatidae; and Deviatidae is closely related to Dorsomarginalia or Strongylidium–Hemiamphisiella–Pseudouroleptus.


Phytotaxa ◽  
2015 ◽  
Vol 227 (2) ◽  
pp. 147 ◽  
Author(s):  
Marco Antonio Cueva Manchego ◽  
STACEY DEWITT SMITH ◽  
SEGUNDO LEIVA GONZÁLES

Iochroma amicorum M. Cueva, S. D. Sm. & S. Leiva (Solanaceae), a new species from cloud forests of Central Peru, is described and illustrated. Phylogenetic analyses of DNA sequence data suggest that Iochroma amicorum is closely related to I. nitidum, I. umbellatum, I. grandiflorum and I. tingoanum, which collectively form the “U” clade of Iochrominae. Certain morphological characteristics of calyx and corolla as well as the type of habitat appear to be common in species of this clade. Iochroma amicorum is easily distinguished from other members of the “U” clade by its campanulate or funnel-shaped corolla with short and slightly reflexed lobes, the presence of an expanded stapet at the point of filament insertion with short lateral extensions united to the corolla, and its globose usually white fruits with tinges of purple at the base. Distribution, phenology and are discussed together with the position of the new species in Iochrominae. Iochroma amicorum is assessed as Endangered according to IUCN criteria B1ab (i, iii)


PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e9529
Author(s):  
Mark A. Freeman ◽  
Tetsuya Yanagida ◽  
Àrni Kristmundsson

Gastrointestinal myxosporean parasites from the genus Enteromyxum are known to cause severe disease, resulting in high mortalities in numerous species of cultured marine fishes globally. Originally described as Myxidium spp., they were transferred to a new genus, Enteromyxum, to emphasize their novel characteristics. Their retention in the family Myxidiidae at the time was warranted, but more comprehensive phylogenetic analyses have since demonstrated the need for a new family for these parasites. We discovered a novel Enteromyxum in wild fish from Malaysia and herein describe the fourth species in the genus and erect a new family, the Enteromyxidae n. fam., to accommodate them. Enteromyxum caesio n. sp. is described infecting the tissues of the stomach in the redbelly yellowtail fusilier, Caesio cuning, from Malaysia. The new species is distinct from all others in the genus, as the myxospores although morphologically similar, are significantly smaller in size. Furthermore, small subunit ribosomal DNA sequence data reveal that E. caesio is <84% similar to others in the genus, but collectively they form a robust and discrete clade, the Enteromyxidae n. fam., which is placed as a sister taxon to other histozoic marine myxosporeans. In addition, we describe, using transmission electron microscopy, the epicellular stages of Enteromyxum fugu and show a scanning electron micrograph of a mature myxospore of E. caesio detailing the otherwise indistinct sutural line, features of the polar capsules and spore valve ridges. The Enteromyxidae n. fam. is a commercially important group of parasites infecting the gastrointestinal tract of marine fishes and the histozoic species can cause the disease enteromyxosis in intensive finfish aquaculture facilities. Epicellular and sloughed histozoic stages are responsible for fish-to-fish transmission in net pen aquaculture systems but actinospores from an annelid host are thought to be necessary for transmission to fish in the wild.


Phytotaxa ◽  
2020 ◽  
Vol 441 (1) ◽  
pp. 47-59
Author(s):  
JIN-FEN HAN ◽  
FANG-RU NAN ◽  
JIA FENG ◽  
JUN-PING LV ◽  
QI LIU ◽  
...  

Four putative “Chantransia” isolates were collected from four locations in Hubei and Yunnan Provinces, China. Morphological analyses were conducted on all isolates. Two specimens (HB26 and YN2) fit the morphological description of A. pygmaea, while the other two isolates (YN1 and YN3) varied in morphology, but were within the circumscription of Audouinella hermannii. Due to the fact that the morphological characters of the “Chantransia” stages of order Batrachospermales and the species of genus Audouinella are too similar to be distinguished, a molecular analysis was performed to clarify the phylogenetic position of these four isolates based on rbcL and psbA sequences. Two “pygmaea” specimens collected from Jiugong Mountain, Hubei Province (HB26) and Shimen Gorge, Yunnan Province (YN2), such as S. jiugongshanensis and S. shimenxiaensis, are proposed primarily based on the DNA sequence data generated in this study. The description of these two new species provides more molecular data for phylogenetic analysis of the genus Sheathia. In addition to these newly described species, the results strongly support that those “hermannii” isolates (YN1 and YN3) collected from Yunnan Province were the “Chantransia” of S. arcuata. However, their gametophyte stages have not been found, meaning that critical diagnostic morphological features were unavailable and molecular methods were the only means for ascertaining their phylogenetic position. Considering the extensive application of the rbcL and psbA genes in phylogenetic analyses of freshwater red algae, we recommend using these two genes to identify species when no morphological characteristics are available.


2013 ◽  
Vol 63 (Pt_5) ◽  
pp. 1912-1921 ◽  
Author(s):  
Xumiao Chen ◽  
Ying Yan ◽  
Xiaozhong Hu ◽  
Mingzhuang Zhu ◽  
Honggang Ma ◽  
...  

The morphology and morphogenesis of the stylonychine hypotrich Rigidohymena candens (Kahl, 1932) Berger, 2011, isolated from garden soil in Qingdao, China, were investigated using live observation and protargol impregnation methods. The Qingdao isolate possesses all diagnostic morphological characters of R. candens. The main events during binary fission are as follows: (i) the proter retains the parental adoral zone of membranelles entirely, whereas the old undulating membranes dedifferentiate into an anlage that gives rise to the leftmost frontal cirrus and the new undulating membranes of the proter; (ii) five streaks of fronto-ventral-transverse cirral anlagen are segmented in the pattern 3 : 3 : 3 : 4 : 4 from left to right, which form two frontal, four frontoventral, one buccal, five ventral and five transverse cirri, respectively; (iii) dorsal morphogenesis is in the typical Oxytricha pattern; (iv) three caudal cirri are formed, one at the posterior end of each of dorsal kineties 1, 2 and 4; and (v) the postoral ventral cirrus V/3 is not involved in primordia formation. The morphological and morphogenetic observations and phylogenetic analyses based on the small-subunit rDNA sequence data support the validity of Rigidohymena Berger, 2011 and its systematic position in the subfamily Stylonychinae.


2013 ◽  
Vol 63 (Pt_3) ◽  
pp. 1155-1164 ◽  
Author(s):  
Xumiao Chen ◽  
Miao Miao ◽  
Honggang Ma ◽  
Chen Shao ◽  
Khaled A. S. Al-Rasheid

A novel stichotrich ciliate, Strongylidium orientale sp. nov., was discovered from a mangrove river in Hong Kong, southern China, and its morphology was investigated through observations in vivo and after protargol impregnation. Cells are 80–120×35–50 µm in vivo and fusiform in shape, with rounded anterior and tapered posterior ends. It is characterized by its brackish habitat and by the presence of two types of cortical granules arranged irregularly throughout the cortex. Morphogenetic events of cell division and physiological reorganization are described. The main ontogenetic features were: (i) only the posterior portion of the parental adoral zone of membranelles was renewed by dedifferentiation of the old structures; (ii) the oral primordium in the opisthe occurred apokinetally; (iii) the left and right ventral rows originated intrakinetally and the final left ventral row was spliced from two cirri from the frontoventral cirral anlage, a short cirral row from the anlage for the right ventral row and a long cirral row which was formed from the whole anlage of the left ventral row; (iv) the marginal rows developed intrakinetally; (v) the dorsal kineties replicated entirely de novo and did not fragment; and (vi) the two macronuclear nodules fused into a mass and then divided. Based on small-subunit rRNA gene sequences, phylogenetic analyses showed a close relationship with its congener Strongylidium pseudocrassum and with the genus Pseudouroleptus.


Phytotaxa ◽  
2016 ◽  
Vol 263 (3) ◽  
pp. 219 ◽  
Author(s):  
MARIA JOSÉ REIS DA ROCHA ◽  
PAULO JOSÉ FERNANDES GUIMARÃES ◽  
FABIÁN A. MICHELANGELI ◽  
ROSANA ROMERO

Poteranthera (Melastomataceae) is a genus of small, annual herbs with narrow leaves, that inhabit humid savannas in South America and are visible only when in bloom. Due to their size and paucity of collections, the phylogenetic position of Poteranthera has been uncertain to this point. Poteranthera has been at times associated, confused, or placed in Acisanthera and/or Siphanthera. Phylogenetic analyses based on DNA sequence data place Poteranthera unequivocally within the Microlicieae and not closely related to Acisanthera or Siphantera. These results are consistent with seed and anther morphology. Putative morphological synapomorphies for this genus are the glandular hairs restricted to the leaf margins and the apically constricted hypanthium. Based on morphology, Acisanthera leptalea seems better placed in Poteranthera and the new combination Poteranthera leptalea is made. An expanded generic description is also provided.


Sign in / Sign up

Export Citation Format

Share Document