Rhabditis (Oscheius) colombiana n. sp. (Nematoda: Rhabditidae), a necromenic associate of the subterranean burrower bug Cyrtomenus bergi (Hemiptera: Cydnidae) from the Cauca Valley, Colombia

Nematology ◽  
2005 ◽  
Vol 7 (3) ◽  
pp. 363-373 ◽  
Author(s):  
S. Patricia Stock ◽  
Ana Caicedo ◽  
Paul Calatayud

AbstractRhabditis (Oscheius) colombiana n. sp. is described as a necromenic associate of the burrower bug Cyrtomenus bergi (Hemiptera: Cydnidae) collected in the Cauca Valley, Colombia. The new species resembles others of the insectivora-group, viz, Rhabditis (O.) insectivora Körner, 1954 and Rhabditis (O.) lucianii Maupas, 1919, in a number of morphological and life history traits, but can be separated by a combination of morphological and morphometric characters. The most distinctive morphological features that separate R. (O.) colombiana n. sp. from these two Rhabditis species are the total size of both males and females, which are much shorter and slimmer in the new species; the size of the male spicules and the values of ratios b and c. Additionally, molecular data (18S rDNA sequences) and phylogenetic analyses demonstrated the distinctiveness of this species when compared to a number of other Rhabditis (Oscheius) species.

2019 ◽  
Vol 152 (3) ◽  
pp. 499-506 ◽  
Author(s):  
Oleg N. Shchepin ◽  
Martin Schnittler ◽  
Nikki H.A. Dagamac ◽  
Dmitry V. Leontyev ◽  
Yuri K. Novozhilov

Background and aims – Recent studies showed the position of two slime mould species with microscopic sporocarps, Echinosteliopsis oligospora and Echinostelium bisporum, within the class Myxomycetes. These minute species are seldom seen in studies based on detection of sporocarps and can easily be confused with protosteloid amoebozoans.Methods – We searched all published ePCR data sets that targeted myxomycete 18S rDNA for the presence of environmental sequences similar to E. oligospora and Echinosteliales in traditional circumscription, and performed phylogenetic analyses that included short environmental sequences and full-length 18S rDNA sequences representing all the major groups of myxomycetes.Key results – We report 19 unique sequences which are closely related to E. bisporum or E. oligospora based on sequence similarity (73.1–95.2% similarity) and which form well-supported monophyletic clades with these species in phylogenetic analyses. They may represent new species that are not yet described. Our phylogeny based on full-length 18S rDNA sequences further confirms the position of E. bisporum and E. oligospora within myxomycetes and the paraphyly of the order Echinosteliales in its traditional circumscription.Conclusions – Our results show that ePCR-based studies can reveal myxomycete taxa that often escape detection by traditional approaches, including potentially new species, and thus provide valuable new data on diversity and ecology of myxomycetes. As such, strategies for studying myxomycetes biodiversity should be revised, focusing also on molecular detection techniques in addition to the sporocarp-based ones.


2020 ◽  
Vol 94 ◽  
Author(s):  
M. Hosseinvand ◽  
A. Eskandari ◽  
S. Ganjkhanloo ◽  
R. Ghaderi ◽  
P. Castillo ◽  
...  

Abstract During several nematological surveys in cultivated and natural habitats in Khuzestan and Zanjan provinces of Iran, a new species, Bitylenchus parvulus n. sp., two new records for Iran – namely, Tylenchorhynchus agri and Tylenchorhynchus graciliformis – and a population of Bitylenchus parvus and one of Sauertylenchus maximus were recovered and characterized based upon morphological and molecular approaches. The new species is characterized by lip region with five to seven annuli, stylet 17.7 (17.0–18.5) μm long, sub-cylindrical tail narrowing abruptly near terminus giving a bluntly digitate shape to the tail tip, cuticle near anterior part of vulva wrinkled and post-rectal sac occupies whole of tail cavity. The phylogenetic analyses were carried out using molecular data from D2–D3 expansion segments of large ribosomal subunit (28S rRNA) for all studied species and the partial small ribosomal subunit (18S rRNA) for the new species. The representatives of Bitylenchus and Sauertylenchus formed distinct clades from Tylenchorhynchus members, supporting the hypothesis in which Bitylenchus and Sauertylenchus could be considered as valid genera, but rejecting the ‘large-genus’ concept for Tylenchorhynchus. Also, Sauertylenchus ibericus was proposed as a junior synonym of S. maximus based on the results from morphological and phylogenetic analysis. Furthermore, an identification key for all known species included in the three genera Bitylenchus, Tylenchorhynchus and Sauertylenchus is presented herein. The number of transverse annuli on the lip region and presence/absence of post-rectal sac were considered as the main diagnostic characters for classifying the species into seven groups, and other morphological and morphometric characters were subsequently used for distinguishing species in each group.


Phytotaxa ◽  
2018 ◽  
Vol 350 (1) ◽  
pp. 51 ◽  
Author(s):  
YANG GAO ◽  
SHU-ZHEN YAN ◽  
GAO-WEI WANG ◽  
SHUANG-LIN CHEN

Two new myxomycetes from subtropical forests of China, Arcyria aeruginosa sp. nov. and Diderma subochraceum sp. nov., are described and illustrated. Arcyria aeruginosa occurred on rotten stem of bamboo and differs from all known species of the genus in having dense spines on inner surface of cups. The diagnostic feature of D. subochraceum is single-layered peridium which dehisces by longitudinal or stellate slit. Preliminary phylogenetic analyses based on partial 18S rDNA sequences support the establishment of the two new species. Additionally, Didymium saturnus H.W. Keller and Fuligo luteonitens L.G. Krieglst. & Nowotny are reported from China for the first time.


Parasitology ◽  
1999 ◽  
Vol 119 (6) ◽  
pp. 555-561 ◽  
Author(s):  
C. L. ANDERSON ◽  
E. U. CANNING ◽  
B. OKAMURA

Proliferative kidney disease (PKD), a condition associated with high mortality in salmonid fish, represents an abnormal immune response to the presence of an enigmatic myxozoan, which has been designated simply as PKX organism because its generic and specific status are obscure. Phylogenetic analyses of partial sequences of the 18S rDNA of PKX and of myxozoan parasites infecting the bryozoans Cristatella mucedo, Pectinatella magnifica and Plumatella rugosa, including the previously named Tetracapsula bryozoides from C. mucedo, showed that these taxa represent a distinct clade that diverged early in the evolution of the Myxozoa before the radiation of the other known myxozoan genera. A common feature of the myxozoans in this clade may be the electron-dense sporoplasmosomes with a lucent bar-like structure, which occur in T. bryozoides and PKX but not in the myxozoans belonging to the established orders Bivalvulida and Multivalvulida. Variation of 0·5–1·1% was found among the PKX 18S rDNA sequences obtained from fish from North America and Europe. The 18S rDNA sequence for T. bryozoides showed that it is a distinct taxon, not closely related to PKX but some sequences from myxozoans infecting 2 of the bryozoan species were so similar to those of PKX as to be indistinguishable. Other sequences from the new myxozoans in bryozoans at first appeared distinct from PKX in a maximum likelihood tree but, when analysed further, were also found to be phylogenetically indistinguishable from PKX. We propose that at least some variants of these new myxozoans from bryozoans are able to infect and multiply in salmonid fish, in which they stimulate the immune reaction and cause PKD but are unable to form mature spores to complete their development.


Phytotaxa ◽  
2017 ◽  
Vol 309 (3) ◽  
pp. 217 ◽  
Author(s):  
YUAN-YUAN CHEN ◽  
MIN WANG ◽  
BO ZHANG ◽  
BAO-KAI CUI

We describe herein the Neoalbatrellus odorus sp. nov. accounting on its peculiar morphological features and molecular data. It is characterized by fleshy basidiomata with a deep violet to dark violet pileal surface, which turns blackish blue and glossy after drying. It also has a white pore surface, light violet to bluish violet stipe, simple septate generative hyphae, and thick-walled, non-amyloid basidiospores. The phylogenetic analyses, based on ITS and 28S rDNA sequences of Neoalbatrellus and its related genera, were performed using Maximum Parsimony, Maximum Likelihood and Bayesian Inference, confirming the affiliation of the new species to Neoalbatrellus.


2019 ◽  
Vol 94 ◽  
Author(s):  
P.R. Singh ◽  
M. Couvreur ◽  
W. Decraemer ◽  
W. Bert

AbstractA survey for slug-associated nematodes in five locations of East and West Flanders in Belgium revealed the presence of one new and six known slug-parasitic nematodes,Agfa flexilis(Dujardin, 1845),Alloionema appendiculatum(Schneider, 1859),Angiostoma dentiferum(Mengert, 1953),Angiostoma limacis(Dujardin, 1845),Angiostoma norvegicum(Rosset al., 2017) andPhasmarhabditis hermaphrodita(Schneider, 1859).Angiostoma norvegicumandP.hermaphroditaare recorded for the first time in Belgium. The six known species are documented by light microscopy (LM) microphotographs and informative DNA sequences.Angiostoma gandavensisn. sp. (Angiostomatidae), discovered from arionid slugs, is described based on light microscopy, scanning electron microscopy (SEM) and molecular data. Based on analyses of D2D3 expansion segment of 28S and 18S rDNA sequences, this new species is found to be related toA.limacis,A.norvegicum,A.margaretae(Rosset al., 2011) andA.milacis(Ivanova and Wilson, 2009). The new species can be distinguished from these others based on morphological characters such as the distinctive mucronate structures at the tail tip of both sexes, presence of lateral ala, reflexed female ovaries and the number and arrangement pattern of male genital papillae.


Nematology ◽  
2018 ◽  
Vol 20 (1) ◽  
pp. 81-95 ◽  
Author(s):  
Daniel Leduc ◽  
Frederic Sinniger

Because of their relatively simple body plan, the number of morphological characters used to differentiate between closely related nematode genera is often limited. In addition, boundaries among genera sometimes become blurred due to the appearance of new trait combinations as more new species are described. Molecular phylogenetic analyses can address the shortcomings of morphological taxonomy by clarifying relationships among closely related species and genera and can help identify which morphological characters are taxonomically informative. Here, we describeLaxus sakihariiaesp. n. from shallow subtidal sands on Sesoko Island in the Okinawa prefecture, investigate phylogenetic relationships with other stilbonematine species and genera based on SSU rDNA sequences, and provide the first LSU rDNA sequence for the subfamily. The new species can be easily distinguished from all other species of the genus by the presence in the male of subventral and ventral rows of stout and spine-like setae in the pre- and postcloacal regions. This feature suggests affinities with the closely related genusLeptonemella, although the SSU consensus tree clearly shows that the new species forms a monophyletic clade together with the otherLaxusspecies for which sequences are available. The structure of the cephalic capsule inL. sakihariiaesp. n., which consists of a block layer between the median and basal zones of the cephalic cuticle, is consistent with the placement of this species. This trait is not currently used as a diagnostic feature, but our finding suggests that the structure of the cephalic capsule may be taxonomically useful for differentiating between some stilbonematine genera.


Phytotaxa ◽  
2016 ◽  
Vol 289 (1) ◽  
pp. 59 ◽  
Author(s):  
DIOGO X. LIMA ◽  
KERSTIN VOIGT ◽  
CARLOS A.F. DE SOUZA ◽  
RAFAEL J.V. DE OLIVEIRA ◽  
CRISTINA M. SOUZA-MOTTA ◽  
...  

The Backusella genus comprises mucoralean saprobes that inhabit in mainly soil and form transitorily curved (when young, erect at maturity) sporangiophores arising directly from the substratum, with simultaneous production of both sporangia and sporangiola. During a study of Mucorales in soil from an Atlantic Rainforest in Pernambuco, Brazil, one specimen of Backusella was isolated and characterized based on morphological, physiological and molecular data (ITS1-5.8S-ITS2 and LSU rDNA sequences). The phylogenetic analyses of the isolate revealed that it belongs to the Backusellaceae and is closely related to species of Backusella. The specimen grew better at 25ºC, with no development at 40ºC, and presented conical and cylindrical columellae possessing a central constriction as well as subglobose sporangiospores 7.5–15 × 5.5–10 µm. Based on the evidences of the analyzed datasets, a new species of Backusella is proposed and a taxonomic key for the species of this genus is provided.


Author(s):  
Rebecca J. Rundell ◽  
Brian S. Leander

The spaces between sand grains are home to a myriad of microscopic marine eukaryotes, including kalyptorhynch rhabdocoels equipped with an eversible proboscis that enables them to capture microscopic prey living in these environments. The structure of the kalyptorhynch proboscis separates the two major subclades within the group: the Schizorhynchia (bifurcated proboscis) and the Eukalyptorhynchia (unbranched proboscis). A survey of meiofaunal metazoans in the Pacific north-west led to the discovery of three new schizorhynch species (Undicola tofinoensisgen. nov., sp. nov.,Schizorhinos vancouverensisgen. nov., sp. nov. andLinguabana tulaigen. nov., sp. nov.) and two new eukalyptorhynch species (Thinodactylaina tlaoquiahtensisgen. nov., sp. nov. andRostracilla nuuchahnulthensisgen. nov., sp. nov.). This survey also recovered the putative cosmopolitan eukalyptorhynch (Polycystididae)Gyratrix hermaphroditusEhrenberg, 1831. We performed molecular phylogenetic analyses on 18S rDNA sequences from all five novel isolates and from all available kalyptorhynch species in GenBank. The molecular data supported the monophyly of the Eukalyptorhynchia and Schizorhynchia and helped demonstrate the boundaries between different species within the Kalyptorhynchia.


2015 ◽  
Vol 90 (2) ◽  
pp. 214-222 ◽  
Author(s):  
V. Vidal ◽  
J. Ortiz ◽  
J.I. Diaz ◽  
B. Zafrilla ◽  
M.J. Bonete ◽  
...  

AbstractStegophorus macronectes (Johnston & Mawson, 1942) is a gastrointestinal parasite found in Antarctic seabirds. The original description of the species, which was based only on females, is poor and fragmented with some unclear diagnostic characters. This study provides new morphometric and molecular data on this previously poorly described parasite. Nuclear rDNA sequences (18S, 5.8S, 28S and internal transcribed spacer (ITS) regions) were isolated from S. macronectes specimens collected from the chinstrap penguin Pygoscelis antarctica Forster on Deception Island, Antarctica. Using 18S rDNA sequences, phylogenetic analyses (maximum likelihood, maximum parsimony and Bayesian inference) of the order Spirurida were performed to determine the phylogenetic location of this species. Primer pairs of the ITS regions were designed for genus-level identification of specimens, regardless of their cycle, as an alternative to coprological methods. The utility of this molecular method for identification of morphologically altered specimens is also discussed.


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