Molecular phylogeny of Acrobeloides and Cephalobus (Nematoda: Cephalobidae) reveals paraphyletic taxa and recurrent evolution of simple labial morphology

Nematology ◽  
2006 ◽  
Vol 8 (6) ◽  
pp. 819-836 ◽  
Author(s):  
Steven Nadler ◽  
Ashleigh Smythe

AbstractMembers of the family Cephalobidae (Nematoda) are among the most common and morphologically striking soil nematodes. Many members of Cephalobidae have extensive lip elaborations called probolae, but two taxonomically problematic genera, Acrobeloides and Cephalobus, have simple, low probolae. We sequenced a portion of the nuclear large subunit ribosomal DNA for 33 cultures of Acrobeloides and Cephalobus. A phylogenetic analysis of these data, plus sequences representing other members of Cephalobina, revealed a core clade of 22 closely related taxa, but did not represent Acrobeloides and Cephalobus as monophyletic. The dominant feature used in morphological taxonomy of Cephalobidae, the lip region, was homoplastic according to the molecular phylogenetic hypothesis. Contrary to previous suggestions, taxa with simple probolae have arisen multiple times from taxa with complex probolae. Cultures were also examined for mode of reproduction (presumed parthenogenetic vs sexual) and three morphological characters commonly used in generic diagnoses: the shape of the corpus in profile; the number of lateral incisures; and the terminal extent of the lateral field. Most cultures, including all 22 members of the core clade, lacked males and were presumed to be parthenogenetic, but several independent origins of sexually reproducing taxa were found. Of the morphological characters, only the corpus shape was consistent with the molecular phylogeny, however, the utility of this character is also questioned. Many genera with complex probolae were also paraphyletic, including Nothacrobeles, Zeldia and Cervidellus, indicating the need for more comprehensive phylogenies and a broad taxonomic revision of the family.

2020 ◽  
Vol 190 (2) ◽  
pp. 518-531 ◽  
Author(s):  
Ahmed J Saadi ◽  
Angus Davison ◽  
Christopher M Wade

Abstract We have undertaken a comprehensive molecular phylogenetic analysis of the Hygrophila based on 3112 sites of the large subunit and 5.8S ribosomal RNA genes. A clear basal division between Chilinoidea and Lymnaeoidea is observed. The monophyly of Acroloxidae, Lymnaeidae and Physidae is also well established. However, Planorbidae are not supported as a monophyletic group, because the Bulinidae cluster within Planorbidae. The Amphipepleinae within Lymnaeidae and both Planorbinae and Ancylinae within Planorbidae are strongly supported as monophyletic subfamilies. However, the Aplexinae within Physidae and the Lymnaeinae within Lymnaeidae are not recovered. A new taxonomic revision of the Hygrophila is proposed based on the findings of this molecular phylogeny, and the implications for the evolution of chirality are discussed.


2020 ◽  
pp. 1-37
Author(s):  
Markéta Kirstová ◽  
Robin Kundrata ◽  
Petr Kočárek

Abstract We present herein the first phylogenetic analysis of the genus Chelidura and the taxonomic revision of the genus Chelidurella, stat. restit., based on DNA sequences. The results confirm the generic status of Chelidurella Verhoeff, 1902 and Mesochelidura Verhoeff, 1902, and they are removed from the synonymy with Chelidura and reinstated as valid genera. Many individual Chelidurella species are defined based on the combination of a few variable characters on the pygidium and forceps, and the systematics and phylogeny of this genus are unclear. The validity of most of the species is revisited here by molecular phylogenetic analyses, and individual morphological characters are evaluated for their relevance in the identification of all described species. We describe two new species to science, Chelidurella galvagnii Kirstová & Kočárek, sp. nov. from Austria, and C. pseudovignai Kočárek & Kirstová, sp. nov. from Italy and Austria; two species, C. guentheri Galvagni, 1994 and C. tatrica Chládek, 2017 are newly synonymized. Critical diagnostic characters are illustrated, and an identification key for males of Chelidurella is provided.


2021 ◽  
Vol 307 (2) ◽  
Author(s):  
Pau Carnicero ◽  
Núria Garcia-Jacas ◽  
Llorenç Sáez ◽  
Theophanis Constantinidis ◽  
Mercè Galbany-Casals

AbstractThe eastern Mediterranean basin hosts a remarkably high plant diversity. Historical connections between currently isolated areas across the Aegean region and long-distance dispersal events have been invoked to explain current distribution patterns of species. According to most recent treatments, at least two Cymbalaria species occur in this area, Cymbalaria microcalyx and C. longipes. The former comprises several intraspecific taxa, treated at different ranks by different authors based on morphological data, evidencing the need of a taxonomic revision. Additionally, some populations of C. microcalyx show exclusive morphological characters that do not match any described taxon. Here, we aim to shed light on the systematics of eastern Mediterranean Cymbalaria and to propose a classification informed by various sources of evidence. We performed molecular phylogenetic analyses using ITS, 3’ETS, ndhF and rpl32-trnL sequences and estimated the ploidy level of some taxa performing relative genome size measures. Molecular data combined with morphology support the division of traditionally delimited C. microcalyx into C. acutiloba, C. microcalyx and C. minor, corresponding to well-delimited nrDNA lineages. Furthermore, we propose to combine C. microcalyx subsp. paradoxa at the species level. A group of specimens previously thought to belong to Cymbalaria microcalyx constitute a well-defined phylogenetic and morphological entity and are described here as a new species, Cymbalaria spetae. Cymbalaria longipes is non-monophyletic, but characterized by being glabrous and diploid, unlike other eastern species. The nrDNA data suggest at least two dispersals from the mainland to the Aegean Islands, potentially facilitated by marine regressions.


Zootaxa ◽  
2018 ◽  
Vol 4526 (3) ◽  
pp. 251 ◽  
Author(s):  
VIRGINIA LEÓN-RÈGAGNON ◽  
JANET TOPAN

Lung flukes of the genus Haematoloechus Looss, 1899 are common parasites of anurans worldwide, but the taxonomy of the group has been confusing. In this taxonomic revision, 89 species of Haematoloechus (= Pneumonoeces Looss, 1902, Ostioloides Odening, 1960, Ostiolum Pratt, 1903, Skrjabinoeces Sudarikov, 1950, Neohaematoloechus Odening, 1960, Metahaematoloechus Yamaguti, 1971) are listed. Of these, 70 are considered valid, three are species inquirendae (H. legrandi Mañé–Garzón & Gil, 1959, H. latoricensis Kozák, 1968 & H. vitelloconfluentum (Rai, 1962) Saeed, Al–Barwari & Al-Harmni, 2007), one is a nomen nudum H. sudarikovi Belouss, 1962, 14 are junior synonyms and one belongs to Ostioloides. This publication also describes three new species, H. occidentalis n. sp., H. veracruzanus n. sp. and H. mexicanus n. sp., parasitizing species of Rana Linnaeus in Mexico and redescribes Haematoloechus caballeroi (Skrjabin & Antipin, 1962) Yamaguti, 1971. The phylogenetic hypotheses based on sequences of mitochondrial and ribosomal DNA of Haematoloechus spp. show that genera proposed on the basis of morphological characters are not supported. The host records for species of Haematoloechus, together with the phylogenetic hypothesis of the genus, suggest that this host-parasite association predates the ranid diversification in the Cretaceous. 


Nematology ◽  
2008 ◽  
Vol 10 (6) ◽  
pp. 925-955 ◽  
Author(s):  
Natsumi Kanzaki ◽  
Robin M. Giblin-Davis ◽  
Yasmin J. Cardoza ◽  
Weimin Ye ◽  
Kenneth F. Raffa ◽  
...  

Abstract Two species of aphelench, Bursaphelenchus rufipennis n. sp. and Ektaphelenchus obtusus, were isolated from the 'nematangia', cocoon-like structures found at the base of the hind wings of Dendroctonus rufipennis. The nematangia contained adult females of E. obtusus and the dauer juveniles of B. rufipennis n. sp. Only B. rufipennis n. sp. could be cultured on Monilinia fructicola on LGPDA (lactic acid-treated, glycerol-supplemented, potato dextrose agar). The new species of Bursaphelenchus is described and figured and some additional morphological characters are ascribed to E. obtusus, E. josephi, E. sandiaensis, E. smaelus (= E. prolobos) and E. terebranus after examination of type and/or voucher specimens. Bursaphelenchus rufipennis n. sp. has an adult body length of ca 500-1000 μm, medium a ratios (ca 25-38 for females and ca 30-40 for males), b ratios of ca 8-13 (female) and 7-11 (male), c ratios of ca 15-22 (female and male), c′ ratios of ca 3-4 (female) and ca 2-3 (male), and is characterised by three incisures in the lateral field, mitten-shaped spicules and a conical female tail that curves ventrally and possesses a variable tail tip. The new species is morphologically closest to B. corneolus, B. curvicaudatus, B. gerberae, B. paracorneolus and B. talonus. Morphological examination of type and/or voucher specimens of five Ektaphelenchus species revealed coarse transverse body annulation and three pairs of male caudal papillae (except for the two species where males are not described). Clear typological differences were observed among these five Ektaphelenchus species in the structure of the lip region, presence/absence of stylet knobs and male spicule morphology. Although these characters have not been consistently documented in the past, they may be diagnostic for species in the genus. Molecular phylogenetic analysis based on SSU and D2/D3 LSU sequences revealed that B. rufipennis n. sp. was closest to B. paracorneolus and that E. obtusus was closest to species of Ektaphelenchoides and a Cryptaphelenchus sp.


Zootaxa ◽  
2010 ◽  
Vol 2408 (1) ◽  
pp. 1 ◽  
Author(s):  
C. DELAND ◽  
C. B. CAMERON ◽  
K. P. RAO ◽  
W. E. RITTER ◽  
T. H. BULLOCK

The family Harrimaniidae (Hemichordata: Enteropneusta) is revised on the basis of morphological characters. The number of harrimaniid genera is increased to nine by the addition of Horstia n. gen., Mesoglossus n. gen., Ritteria n. gen. and Saxipendium, a genus previously assigned to the monospecific family Saxipendiidae. The number of species is increased to 34, resulting from the description of five new species from the eastern Pacific — Horstia kincaidi, Mesoglossus intermedius, M. macginitiei, Protoglossus mackiei and Ritteria ambigua. A description is supplied for a sixth harrimaniid species, Stereobalanus willeyi Ritter & Davis, 1904, which previously had the status of a nomen nudum. Four harrimaniids previously assigned to the genus Saccoglossus are transfered to the genus Mesoglossus — M. bournei, M. caraibicus, M. gurneyi and M. pygmaeus, while Saccoglossus borealis is reassigned to the genus Harrimania. Notes on habitat and zoogeography are included for the seven foregoing species and a table of diagnostic characters for existing and new species and a dichotomous key to the enteropneust families and harrimaniid genera are provided. Finally, a phylogenetic hypothesis concerning the Harrimaniidae is postulated, with discussion on the evolution of the group.


2016 ◽  
Vol 47 (1) ◽  
pp. 53-82 ◽  
Author(s):  
Werner P. Strümpher ◽  
Martin H. Villet ◽  
Catherine L. Sole ◽  
Clarke H. Scholtz

Extant genera and subgenera of the Trogidae (Coleoptera: Scarabaeoidea) are reviewed. Contemporary classifications of this family have been based exclusively on morphological characters. The first molecular phylogeny for the family recently provided strong support for the relationships between morphologically defined genera and subgenera. On the basis of morphological, molecular and biogeographical evidence, certain taxonomic changes to the genus-level classification of the family are now proposed. The family is confirmed as consisting of two subfamilies, Omorginae Nikolajev and Troginae MacLeay, the former with two genera,OmorgusErichson andPolynoncusBurmeister, and the latter with two genera,TroxFabricius andPhoberusMacLeaystat. rev.Phoberusis restored to generic rank to include all Afrotropical (including Madagascan endemic) species;Afromorgusis confirmed at subgeneric rank within the genusOmorgus; and the monotypic Madagascan genusMadagatroxsyn. n.is synonymised withPhoberus.The current synonymies ofPseudotroxRobinson (withTrox),ChesasBurmeister,LagopelusBurmeister andMegalotroxPreudhomme de Borre (all withOmorgus) are all accepted to avoid creating speculative synonyms before definitive phylogenetic evidence is available. New combinations resulting from restoringPhoberusto a monophyletic genus are listed in Appendix A.


Phytotaxa ◽  
2019 ◽  
Vol 427 (1) ◽  
pp. 31-42
Author(s):  
LEI SHU ◽  
RUI-LIANG ZHU

Based on molecular phylogenetic analyses and morphological characters, a new species from Bangladesh, northern Vietnam, and southwestern China, Leptolejeunea nigra, is described. It is mostly similar to L. balansae but remarkable for having brownish black ocelli in its leaf lobes. In the molecular phylogeny, the samples of L. nigra are not nested within any clade and form an independent lineage. In particular, the molecular dating suggested that the divergence of L. nigra happened in time span of the formation of the Himalayas.


2020 ◽  
Vol 193 (3) ◽  
pp. 287-315 ◽  
Author(s):  
Ekaterina A Shepeleva ◽  
Mikhail I Schelkunov ◽  
Michal Hroneš ◽  
Michal Sochor ◽  
Martin Dančák ◽  
...  

Abstract Thismia is a genus of > 80 mycoheterotrophic species characterized by a peculiar appearance and complex floral morphology. A significant proportion of the species and morphological diversity of Thismia has only been uncovered in the past two decades, and new discoveries continue to be made. Given that many new data have recently become available, and the most comprehensive taxonomic revision of the genus from 1938 addresses less than half of the currently known species, previous hypotheses for species relationships and infrageneric taxonomic classification in Thismia was in need of review. Extensive molecular phylogenetic studies of Thismia at the genus level have never been presented. We investigate the phylogenetic relationships of 41 species (and one variety) of Thismia from the Old World. Our study comprises 68 specimens (for 28 of which the data were newly generated), including outgroup taxa broadly representing Thismiaceae (= Burmanniaceae p.p. sensuAPG IV, 2016), and is based on two nuclear and one mitochondrial marker. We use maximum likelihood and Bayesian inference to infer relationships among the taxa. We also constructed a morphological dataset of 12 mostly floral characters, comparing these characters to hypotheses based on molecular evidence to identify putative synapomorphies for major clades and to discuss hypotheses regarding the evolution of structural traits in the genus. Our analyses indicate that the majority of currently accepted infrageneric taxa of Thismia are polyphyletic. We find support for the monophyly of the Old World group, in which we recognize five well-supported lineages (clades); the only New World species studied appears to be related to the Neotropical genus Tiputinia. Ancestral state reconstructions demonstrate that the evolution of most morphological characters was homoplastic, but we identify characters that provide each of the five clades of Old World Thismia with a unique morphological description. The geographical distribution of the species under study is also shown to be consistent with the major clades. Our investigation provides a phylogenetic basis for the development of a novel sectional classification of Thismia reflecting morphological and geographical traits.


Zootaxa ◽  
2018 ◽  
Vol 4369 (3) ◽  
pp. 406 ◽  
Author(s):  
MAJID PEDRAM ◽  
MAHYA SOLEYMANZADEH ◽  
EBRAHIM POURJAM ◽  
MAHYAR MOBASSERI

Malenchus geraerti n. sp., recovered from natural regions of northern Iran, is described and illustrated based on morphological, morphometric and molecular data. The new species is characterized by having females with a short body, an anteriorly wide S-shaped amphidial opening narrowing posteriorly, cuticle with prominent annuli, lateral field a plain band with smooth margins, muscular metacorpus with well-developed valve and corresponding plates, spermatheca filled with small spheroid sperm cells, vulva sunken in body with large epiptygma and no flap, and conical tail tapering gradually to a more or less pointed tip. Males of the new species are characterized by having a short body, tylenchoid spicules, adcloacal bursa with smooth margin and tail similar to that of the female. Morphologically, the new species is similar to five known species of the genus: M. fusiformis, M. machadoi, M. pachycephalus, M. solovjovae and M. undulatus. It most closely resembles M. pachycephalus, but as a cryptic species it can be differentiated using morphological and molecular characteristics. Comparisons with the four other aforementioned species are also discussed. Molecular phylogenetic studies using partial sequences of small and large subunit ribosomal DNA fragments reveal that the new species forms a clade with the species M. neosulcus in the small subunit (SSU) rDNA, and two species of Lelenchus in the large subunit (LSU) rDNA tree. 


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