No full-text available
To read the full-text of this research,
you can request a copy directly from the authors.
Morphology and Taxonomy of Bathyodontina (Dorylaimida)
Abstract
Detailed studies of the morphology of head region and stoma with associated muscles of Mononchulus, Oionchus and Bathyodontus show that it is justified to regard these genera as representing a taxonomic unit. This is further supported by the location of the oesophageal gland nuclei and orifices. However, there exist profound differences in stoma structure between Mononchulus and Oionchus on one hand, and Bathyodontus on the other. Taking into account the recent revision of the mononchs by Jairajpuri (1969) we raise Bathyodontidae to subordinal rank along with Mononchina and Dorylaimina. The subfamilies Bathyodontinae and Mononchulinae are raised to superfamily rank. Isolaimium is excluded from Bathyodontina, but Cryptonchus should possibly be placed near Bathyodontus.
... Cobb (1917) published an excellent and fundamental monograph on 'The Mononchs' with a total of 60 species; this was the basis of all the subsequent studies and revisions. Of the latter, the following are worthy of mention: Andrássy (1958Andrássy ( , 1992aAndrássy ( ,b, 1993, Coomans and Loof (1970), Jairajpuri and Khan (1982) and De Ley and Coomans (1989). A review of freshwater Mononchida occurring in Central Europe was presented by Loof (1999). ...
... A row of ventromedian supplements present. Anderson, 1968); E: Bathyodontus (after Coomans and Loof, 1970); B: Mononchulus (after Coomans and Loof, 1970); C: Oionchus (after Coomans and Loof, 1970); F: Nullonchus (Siddiqi, 1984a); G: Caputonchus (after Siddiqi, 1984b); H: Mulveyellus (after Mulvey and Jensen, 1967); I: Jensenonchus (after Peneva et al., 1998); J: Iotonchus (after Coomans and Khan, 1981); K: Hadronchus (after Mulvey and Jensen, 1967); D: Pharyngeal base (Anatonchoidea) (after Clark, 1960); A-D and F-K: scale bar 20 µm. Sukul, 1971;O. ...
... A row of ventromedian supplements present. Anderson, 1968); E: Bathyodontus (after Coomans and Loof, 1970); B: Mononchulus (after Coomans and Loof, 1970); C: Oionchus (after Coomans and Loof, 1970); F: Nullonchus (Siddiqi, 1984a); G: Caputonchus (after Siddiqi, 1984b); H: Mulveyellus (after Mulvey and Jensen, 1967); I: Jensenonchus (after Peneva et al., 1998); J: Iotonchus (after Coomans and Khan, 1981); K: Hadronchus (after Mulvey and Jensen, 1967); D: Pharyngeal base (Anatonchoidea) (after Clark, 1960); A-D and F-K: scale bar 20 µm. Sukul, 1971;O. ...
This book contains 22 chapters on various aspects of freshwater nematode ecology and taxonomy. Subjects covered include the techniques for processing freshwater nematodes, the composition and distribution of free living freshwater nematodes, their abundance, biomass and diversity, the production of freshwater nematodes, their feeding ecology, patterns in size structure of freshwater nematode communities, different nematode habitats, and computation and application of nematode community indices. It provides descriptions with figures of each taxon at the genus level and above to currently valid genera. For every genus, a complete list of species, with an emphasis on biogeography, is given for primarily freshwater taxa and a list of only those species reported from freshwater bodies is given for the genera that are considered primarily non-freshwater. This book is intended to provide a useful reference to students, beginners and established researchers in the field of freshwater nematology, benthologists, invertebrate biologists, limnologists, ecologists, microbiologists and soil biologists.
... Other relevant contributions devoted to taxonomy of mononchs were published by Jairajpuri and Khan (1982), and . On the other hand, the papers by Coomans and Lima (1965) and Coomans and Loof (1970) are still excellent references to explore and understand the morphology of Mononchina and Bathyodontina, respectively. ...
... Moreover, they include two subgroups, usually classified with the rank of superfamilies (Cryptonchoidea and Mononchuloidea, see below), which differ significantly between them and from the Mononchina, and whose phylogeny has not been clarified definitively. Coomans and Loof (1970;see also De Ley & Coomans, 1989) provided a very detailed morphological study of the genera Bathyodontus (Cryptonchoidea), and Mononchulus and Oionchus (Mononchuloidea), which is herein summarized including their most distinctive features. ...
... The two superfamilies differ significantly in the nature of their stoma and they do not probably conform to a monophyletic group. The papers by Coomans and Loof (1970) and De Ley and Coomans (1989) are excellent contributions to know and understand their morphology and taxonomy. ...
... The genus Bathyodontus was originally placed in Nygolaiminae Thorne, 1935 when described (Fielding, 1950), but subsequently transferred to a separate family, Bathyodontidae (Clark, 1961). Bathyodonts are of particular interest because they have often been viewed as a 'transitional group' between mononchs and dorylaims (Clark, 1961;Yeates, 1967;Coomans & Loof, 1970). ...
... The position of the pharyngeal gland orifices anterior to the nerve ring may represent a synapomorphy for the clade uniting the vertebrate parasites (Dioctophymida and Trichinellida), while caudal glands could represent an innovation of Mononchida, secondarily lost in the insectparasitic Mermithina. It should be noted, however, that support (as assessed by bootstrap percentages) in our analyses for the basal position of Isolaimium within Do-rylaimia is not particularly strong in most cases, and that many of the morphological features noted above are considered derived, rather than primitive (e.g., Coomans & Loof, 1970;Swart & Heyns, 1991). This lack of support, coupled with the unusual morphology of Isolaimium species, may instead indicate that Isolaimida may be more correctly excluded from Dorylaimia, and share more recent common ancestry with other nematode taxa not yet sampled for SSU rDNA sequences. ...
... Clark (1961) placed the superfamily Mononchoidea, with two families: Mononchidae and Bathyodontidae in the suborder Dorylaimina. Coomans and Loof (1970) considered Bathyodontina (comprising Bathyodontoidea and Mononchuloidea) a suborder of Dorylaimida, which at that time also contained Mononchina and Dorylaimina. To Clark (1961), mononchs and bathyodonts were sister taxa, and were more distantly related at the superfamily level to dorylaims. ...
Phylogenetic reconstructions based on 18S rDNA sequence data indicate that Dorylaimida, comprising the suborders Nygolaimina and Dorylaimina, is a monophyletic lineage, but that there is a deep division within Nygolaimina, giving rise to the possibility that Nygolaimina is paraphyletic. A well-supported clade comprising members of the traditional orders Mermithida and Mononchida (including Bathyodontina) forms the sister taxon to the Dorylaimida. Inferred relationships within this clade indicate that Mermithida shares more recent common ancestry with Mononchina than does Bathyodontina. Vertebrate parasites within Dorylaimia (Dioctophymida and Trichinellida) are reconstructed in a sister-taxon relationship with the Mononchida/Dorylaimida lineage. The enigmatic order Isolaimida (represented by Isolaimium) appears to be ancestral to all other Dorylaimia sampled. Expanded taxon sampling for phylogenetic analyses of the subclass raises new possibilities for the reconstruction of hypothetical character states in the common ancestor of Dorylaimia.
... The family Mononchulidae is characterized by buccal cavity strongly sclerotized with long anterior subventral tooth and 2-6 rows of transverse denticles, pharynx with five gland nuclei with anterior one dorsal, located about middle of pharynx far posterior to gland orifice. The family contain two genera Mononchulus Cobb, 1918 andOionchus Cobb, 1913. The genus Oionchus includes predatory soil nematodes which have buccal cavity encircled by pharyngeal tissues. ...
... Nematodes were isolated from soil samples by Cobb's wet sieving technique (Cobb, 1918) followed by a modified Baermann funnel method (Baermann, 1917). Extracted nematodes were killed by gradual heat, fixed in TAF and mounted in dehydrated glycerine (Siddiqi, 1986). ...
Oionchus sindhicus n. sp., is described from specimens collected from soil around the roots of cotton (Gossypium hirsutum L.) from Umerkot, Sindh, Pakistan. The new species is characterized by having a combination of characters: body length of female 0.7-1.0 mm, vulva at 56-59 percent of body length, anterior part of buccal cavity 5-7 µm wide, pharynx 198-238 µm long, tail 30-33 µm long, post uterine sac 10-16 µm in length, apex of dorsal tooth 3-5 µm from anterior end. Morphometric and morphological data of O. paraobtusus Jairajpuri and Khan, 1982 and O. obtusus Cobb, 1913 are also given. These species are described and redescribed for the first time from Pakistan.
... Nerve ring at 30 -40 % of neck length from anterior end. Pharyngeal gland nuclei located as follows: D = 62 -63 %; AS1 = 16 -17 %; AS2 = 19 -21 %; PS1 = 51 -52 %; PS2 = 52 -54 % as per Andrássy (1998); D0 = 53 -59 %; DN = 56 -61 %; DO -DN =2.3 -4.5 %; S1N1 = 62 -66 %; S1N2 = 69 -77 %; S2N = 82 -84 %; S2O = 84 -85 % as per Loof and Coomans (1970). Cardia rounded conoid, gradually tapering to a fi ne pointed tip. ...
... " E collected by Dr. Mizukubo of National Agricultural Research Center, Tsukuba, Japan. Loof and Coomans (1970). Nerve ring at 38 -40 % of total neck length. ...
Two new species of the genus Coomansinema Ahmad and Jairajpuri, 1989 are described and illustrated. C. japonicum n. sp. is characterized by having medium size body (L= 1.40 – 1.45 mm); lip region truncate with completely amalgamated lips; amphideal fovea goblet – shaped; 16 – 20 μm long odontostyle; 23 – 25 μm long odontophore; comparatively anterior position of the second pair of pharyngeal glands; amphidelphic female genital system; longitudinal vulva; males with 48 – 54 μm long spicules; 7 – 8 spaced ventromedian supplements and tail long filiform in female and short conoid in male. C. longicaudatum n. sp. is characterized by having medium size body (L= 1.1 – 1.3 mm); lip region truncate, continuous with completely amalgamated lips; amphideal fovea cup – shaped; 16 – 17 μm long odontostyle; 19 – 20 μm long odontophore; comparatively anterior position of the second pair of pharyngeal glands; amphidelphic female genital system; transverse vulva, intestinal – prerectum junction with a tongue – like structure and 210 – 269 μm long filiform tail. A key to its seven valid species is provided.
... Diphtherophorina Coomans and Loof, 1970 Other suborder ...
... Bathyodontina Coomans and Loof, 1970 ...
... Diphtherophorina Coomans and Loof, 1970 Other suborder ...
... Bathyodontina Coomans and Loof, 1970 ...
Soil Nematodes of Grasslands in Northern China presents research on China's temperate grasslands, providing the findings and results of a large field survey along a transect across the northern temperate grassland. It examines nematode distribution patterns along the transect from trophic group and family, to genus level, also evaluating their relationship with climatic conditions, plant biomass and soil parameters. The book then presents detailed taxonomy information of nematodes to genus or species level, providing keen insights into nematode diversity along the grassland transect in north China. Final sections review the advances and perspectives for the research of soil ecology on soil nematodes in China, including recent major discoveries of soil microbial diversity and eco-function during this field survey. This work will help researchers predict the impact of global change drivers on below ground soil biota and better understand the functioning and services they provide in terrestrial ecosystems. © 2017 Zhejiang University Press. Published by Elsevier Inc. All rights reserved.
... The Triplonchida were conWrmed as an order within the Enoplia, consistent with Siddiqi (1983) but contrary to many earlier classiWcations that were based on morphological data alone and placed part of this group among the Dorylaimia (e.g. Thorne, 1939;Clark, 1961;Siddiqi, 1961Siddiqi, , 1973De Coninck, 1965;Coomans and Loof, 1970). Within the Triplonchida, the Diphtherophoroidea were monophyletic and well supported. ...
... This proximity to the Axonolaimidae is in agreement with morphological analysis by Filipjev (1934), Goodey (1963) and Gerlach andRiemann (1973/1974). In contrast, many classic systems placed this taxon in the Dorylaimia (De Coninck, 1965;Timm, 1969;Coomans and Loof, 1970;Andrássy, 1976;Lorenzen, 1981) or Enoplia (Maggenti, 1982;Inglis, 1983). Mullin et al. (2003Mullin et al. ( , 2005 put Isolaimium in Dorylaimia using molecular analyses but their datasets did not include adequate representation of the Chromadoria to test its relationship with Axonolaimidae; although, their trees are compatible with our results. ...
... The Triplonchida were conWrmed as an order within the Enoplia, consistent with Siddiqi (1983) but contrary to many earlier classiWcations that were based on morphological data alone and placed part of this group among the Dorylaimia (e.g. Thorne, 1939;Clark, 1961;Siddiqi, 1961Siddiqi, , 1973De Coninck, 1965;Coomans and Loof, 1970). Within the Triplonchida, the Diphtherophoroidea were monophyletic and well supported. ...
... This proximity to the Axonolaimidae is in agreement with morphological analysis by Filipjev (1934), Goodey (1963) and Gerlach andRiemann (1973/1974). In contrast, many classic systems placed this taxon in the Dorylaimia (De Coninck, 1965;Timm, 1969;Coomans and Loof, 1970;Andrássy, 1976;Lorenzen, 1981) or Enoplia (Maggenti, 1982;Inglis, 1983). Mullin et al. (2003Mullin et al. ( , 2005 put Isolaimium in Dorylaimia using molecular analyses but their datasets did not include adequate representation of the Chromadoria to test its relationship with Axonolaimidae; although, their trees are compatible with our results. ...
Phylogenetic reconstructions of relations within the phylum Nematoda are inherently difficult but have been advanced with the introduction of large-scale molecular-based techniques. However, the most recent revisions were heavily biased towards terrestrial and parasitic species and greater representation of clades containing marine species (e.g. Araeolaimida, Chromadorida, Desmodorida, Desmoscolecida, Enoplida, and Monhysterida) is needed for accurate coverage of known taxonomic diversity. We now add small subunit ribosomal DNA (SSU rDNA) sequences for 100 previously un-sequenced species of nematodes, including 46 marine taxa. SSU rDNA sequences for >200 taxa have been analysed based on Bayesian inference and LogDet-transformed distances. The resulting phylogenies provide support for (i) the re-classification of the Secernentea as the order Rhabditida that derived from a common ancestor of chromadorean orders Araeolaimida, Chromadorida, Desmodorida, Desmoscolecida, and Monhysterida and (ii) the position of Bunonema close to the Diplogasteroidea in the Rhabditina. Other, previously controversial relationships can now be resolved more clearly: (a) Alaimus, Campydora, and Trischistoma belong in the Enoplida, (b) Isolaimium is placed basally to a big clade containing the Axonolaimidae, Plectidae, and Rhabditida, (c) Xyzzors belongs in the Desmodoridae, (d) Comesomatidae and Cyartonema belongs in the Monhysterida, (e) Globodera belongs in the Hoplolaimidae and (f) Paratylenchus dianeae belongs in the Criconematoidea. However, the SSU gene did not provide significant support for the class Chromadoria or clear evidence for the relationship between the three classes, Enoplia, Dorylaimia, and Chromadoria. Furthermore, across the whole phylum, the phylogenetically informative characters of the SSU gene are not informative in a parsimony analysis, highlighting the short-comings of the parsimony method for large-scale phylogenetic modelling.
... The molecular phylogenetic study of Meldal et al. (2007) confirmed that 1) the Triplonchida is an order within Enoplia, consistent with Siddiqi (1983) but contrary to many earlier classifications that were based on morphological data alone and placed part of this group among the Dorylaimia (Thorne 1939; Clark 1961; Siddiqi 1961, 1973; De Coninck 1965; Coomans & Loof 1970); 2) within Triplonchida, the Diphtherophoroidea were well supported as monophyletic; 3) contrary to morphological classifications, Trischistoma monohystera appears to be more closely related to Enoplida than to Triplonchida as the latter order forms a well supported clade excluding T. monohystera. ...
... The molecular phylogenetic study of Meldal et al. (2007) confirmed that 1) the Triplonchida is an order within Enoplia, consistent with Siddiqi (1983) but contrary to many earlier classifications that were based on morphological data alone and placed part of this group among the Dorylaimia (Thorne 1939;Clark 1961;Siddiqi 1961Siddiqi , 1973De Coninck 1965;Coomans & Loof 1970); 2) within Triplonchida, the Diphtherophoroidea were well supported as monophyletic; 3) contrary to morphological classifications, Trischistoma monohystera appears to be more closely related to Enoplida than to Triplonchida as the latter order forms a well supported clade excluding T. monohystera. ...
We have made an extensive study of New Zealand representatives of nematodes from the family Tripylidae de Man, 1876. Based on SSU DNA sequence data and phylogenetic analysis, the genera Tripylina Brzeski, 1964 and Trischistoma Cobb, 1913 are not closely related to Tripyla Bastian, 1865, the type genus of the family Tripylidae de Man 1876. The genus Tripylina is sister to Trischistoma and Trefusia de Man, 1893 and is more closely related to Enoplida than to Triplonchida. Our phylogenetic results indicate that Tripylina should be placed in Enoplida.
... Bathyodonts, members of the suborder Bathydontina Coomans & Loof, 1970, order Mononchida Jairajpuri, 1969, are a very rare nematode taxon, which, according to its very recent revisions (Andrássy, 2009;Ahmad & Jairajpuri, 2010), includes only four valid genera and 12 valid species. From a systematic perspective, however, they represent a highly interesting group, displaying a peculiar morphological pattern that separates them from the true mononchs, i.e. the components of the other suborder Mononchina Kirjanova & Krall, 1969 of Monon-chida, and raises the question of the true nature of the evolutionary relationship of the two suborders. ...
... Amphid fovea small, funnel-shaped, opening into a small oval orifice which is about 5 µm wide and occupies about one-fifth of lip region diameter. Stoma of intricate structure, as described in detail by Coomans & Loof (1970), 2.6-2.8 times the lip region width long: vestibule very short, 2.5-3.0 µm long; anterior, tubular section 18-20 µm long or as long as lip region width, and with wide lumen; and posterior section 37-39 µm long and with narrower lumen. Pharynx typical of the group, cylindrical, its anterior end surrounding the whole stoma. ...
Bathyodontus mirus (Andrássy, 1956) Hopper & Cairns, 1956, collected in sand dunes of SW Iberian peninsula, is studied. Description, measurements and illustrations (LM pictures) are provided. Iberian specimens are briefly compared to other known populations of the species. And a compendium of Bathyodontus species, including a key to their identification, is also given. This is the first record of a representative of the nematode suborder Bathyodontina in the Iberian-Balearic range and in the Mediterranean region.Se estudia la especie Bathyodontus mirus (Andrássy, 1956) Hopper y Cairns, 1956, recolectada en dunas de arena en el suroeste peninsular. Se presentan una descripción, medidas e ilustraciones (fotografías con microscopía óptica). Los ejemplares ibéricos se comparan brevemente con otras poblaciones conocidas de la misma especie. Y se ofrece un compendio de las especies del género Bathyodontus, incluida una clave para su identification. Se trata de la primera cita de un miembro del suborden Bathyodontina en el ámbito Ibero-balear y en la región Mediterránea.
... The Triplonchida were conWrmed as an order within the Enoplia, consistent with Siddiqi (1983) but contrary to many earlier classiWcations that were based on morphological data alone and placed part of this group among the Dorylaimia (e.g. Thorne, 1939; Clark, 1961; Siddiqi, 1961 Siddiqi, , 1973 De Coninck, 1965; Coomans and Loof, 1970). Within the Triplonchida, the Diphtherophoroidea were monophyletic and well supported. ...
... This proximity to the Axonolaimidae is in agreement with morphological analysis by Filipjev (1934), Goodey (1963) and Gerlach and Riemann (1973/1974). In contrast, many classic systems placed this taxon in the Dorylaimia (De Coninck, 1965; Timm, 1969; Coomans and Loof, 1970; Andrássy, 1976; Lorenzen, 1981) or Enoplia (Maggenti, 1982; Inglis, 1983). Mullin et al. (2003 Mullin et al. ( , 2005) put Isolaimium in Dorylaimia using molecular analyses but their datasets did not include adequate representation of the Chromadoria to test its relationship with Axonolaimidae; although, their trees are compatible with our results. ...
Phylogenetic reconstructions of relations within the phylum Nematoda are inherently difficult but have been advanced with the introduction of large-scale molecular-based techniques. However, the most recent revisions were heavily biased towards terrestrial and parasitic species and greater representation of clades containing marine species (e.g. Araeolaimida, Chromadorida, Desmodorida, Desmoscolecida, Enoplida, and Monhysterida) is needed for accurate coverage of known taxonomic diversity. We now add small subunit ribosomal DNA (SSU rDNA) sequences for 100 previously un-sequenced species of nematodes, including 46 marine taxa. SSU rDNA sequences for >200 taxa have been analysed based on Bayesian inference and LogDet-transformed distances. The resulting phylogenies provide support for (i) the re-classification of the Secernentea as the order Rhabditida that derived from a common ancestor of chromadorean orders Araeolaimida, Chromadorida, Desmodorida, Desmoscolecida, and Monhysterida and (ii) the position of Bunonema close to the Diplogasteroidea in the Rhabditina. Other, previously controversial relationships can now be resolved more clearly: (a) Alaimus, Campydora, and Trischistoma belong in the Enoplida, (b) Isolaimium is placed basally to a big clade containing the Axonolaimidae, Plectidae, and Rhabditida, (c) Xyzzors belongs in the Desmodoridae, (d) Comesomatidae and Cyartonema belongs in the Monhysterida, (e) Globodera belongs in the Hoplolaimidae and (f) Paratylenchus dianeae belongs in the Criconematoidea. However, the SSU gene did not provide significant support for the class Chromadoria or clear evidence for the relationship between the three classes, Enoplia, Dorylaimia, and Chromadoria. Furthermore, across the whole phylum, the phylogenetically informative characters of the SSU gene are not informative in a parsimony analysis, highlighting the short-comings of the parsimony method for large-scale phylogenetic modelling.
... The family Mononchulidae is characterized by buccal cavity strongly sclerotized with long anterior subventral tooth and 2-6 rows of transverse denticles, pharynx with five gland nuclei with anterior one dorsal, located about middle of pharynx far posterior to gland orifice. The family contain two genera Mononchulus Cobb, 1918 andOionchus Cobb, 1913. The genus Oionchus includes predatory soil nematodes which have buccal cavity encircled by pharyngeal tissues. ...
Description of Oionchus sindhicus n. sp., and morphometric data on O. paraobtusus Jairajpuri & Khan, 1982 and O. obtusus Cobb, 1913 (Nematoda Mononchida)
from Pakistan
Abstract
Oionchus sindhicus n.sp., is described from specimens collected from soil around the roots of cotton (Gossypium hirsutum L.) from Umerkot, Sindh, Pakistan. The new species is characterized by having a combination of characters: body length of female 0.7-1.0 mm, vulva at 56-59 percent of body length of female, anterior part of buccal cavity 5-7 µm wide, pharynx 198-210 µm long, tail30-33 µm long, post uterine sac 10-16 µm in length, apex of dorsal tooth 3-5 µm from anterior end. Morphometric and morphological data of O. paraobtusus Jairajpuri & Khan, 1982 and O. obtusus Cobb, 1913 are also given. These species are described and redescribed for the first time from Pakistan.
... Length of posterior gonad  100/body length Coomans & Loof (1970) DN Position of dorsal pharyngeal gland nucleus from anterior end  100 /total neck length DO Orifice of thedorsal pharyngeal gland nucleus from anterior end  100 /total neck length S1N1 ...
Nematodes are among the most successful and diverse taxa in the animal kingdom, combine endless variation with a deceptively conserved anatomical pattern. Nematodes representing the Order Dorylaimida show K-strategies i.e. having a long life-cycle, low reproduction rate, low colonization ability and are sensitive to disturbance and usually live in a habitat with long durational stability, dominate both in number and species, over other soil-inhabiting nematodes. Andrássy while revising the family Qudsianematidae Jairajpuri, 1965 proposed the genus Talanema Andrássy, 1991 for Labronema Thorne, 1939 species having transverse vulva, subdigitate tail and non-contiguous ventromedian supplements. After almost three decades, the genus is still in need of scientific attention as the addition of new species and transfer of previously described Labronema species make a continuum between the Labronema and Talanema species. In the present work, a pure population of L. baqrii Khan, Jairajpuri and Ahmad, 1989 represented by males, females and juveniles isolated from cattle manure from Aligarh, Uttar Pradesh was studied. Herein, we transfer L. baqrii to Talanema and sought to clarify their relationship through molecular and morphological characterization of Talanema baqrii (Khan, Jairajpuri and Ahmad 1989) comb. n. along with the analysis of Labronema species with transverse vulva; conoid, rounded or digitate tail and non-contiguous ventromedian supplements.
... Prior to the erection of the order, Andrássy (1967) placed the suborder Mononchina Kirjanova & Krall, 1969 under the order Dorylaimida Pearse, 1942. Later, Lorenzen (1981 grouped the two suborders Mononchina and Bathydontina Coomans & Loof, 1970under Dorylaimida. Maggenti (1983, 1991 considered Mononchida as a separate order including the two superfamilies Bathydontoidea Clark, 1961 andMononchoidea Filipjev, 1934. ...
Mononchida is an order of predatory nematodes and includes the suborders Bathyodontina and Mononchina. In this survey, sequences of the 18S rDNA were amplified and used to reconstruct the phylogeny of the Mononchina. Phylogenetic analyses using neighbour joining (NJ) and maximum likelihood (ML) were employed with five outgroup taxa and 65 mononch sequences including 14 new sequences from Iran. Both analyses indicated that the Anatonchus is monophyletic. Actus was placed as the sister group of Mylonchulus with weak and strong support, respectively, from the ML and NJ analyses. In both phylogenetic analyses, trees obtained from SSU rDNA alignments were subdivided into five highly- or moderately-supported clades, designated Clade I: Mylonchulus spp., Clade II: Actus salvadoricus, Clade III: Anatonchus spp., a group comprising the genera Clarkus, Coomansus, Miconchus and Prionchulus, Clade IV: Mononchus spp., and Clade V: Granonchulus sp. The 18S rDNA analysis demonstrated that this region of the nuclear genome can be used to resolve the relationships of members of this suborder.
... On the whole, the arming of the esophastome has been described in con tradictory ways. In two studies [4,9], one onchus was mentioned and illustrated; in another one [14], in addition to this onchus, another, smaller dorsal onchus was mentioned. Numerous adult females and more males of M. nodicaudatus collected in Vietnam made it possible to correct and expand the description of this species. ...
The new nematode species Monhystera longivaginata sp. n. and the rare species Mononchulus nodicaudatus (Daday, 1901) collected in waterbodies of Vietnam are described. M. longivaginata sp. n. is morphologically similar to M. paludicola de Man, 1881, but differs from it in a longer and slenderer tail in females, ocelli situated closer to the anterior end of the body, the presence of a postvulval gland cell, and a longer vagina. The genus Monhystera Bastian, 1865 is revised, and several species of this genus (M. lemani Juget, 1969, M. macramphus Filipjev, 1923, M. amabilis Gagarin, 1997, M. hamata Gagarin et Nguyen Vu Thanh, 2005, and M. melnikae Gagarin et Naumova, 2010) are transferred to the genus Eumonhystera Andrássy, 1981 as E. lemani (Juget, 1969) comb. nov., E. macramphus (Filipjev, 1929) comb. nov., E. amabilis (Gagarin, 1997) comb. nov., E. hamata (Gagarin et Nguyen Vu Thanh, 2005) comb. nov., and E. melnikae (Gagarin et Naumova, 2010) comb. nov. [In Russian & English]
... Thus, the evolution of Campydoridae was believed to represent 'an independent development of the pre-bathyodontidstock' (Yeates, 1967); the systematic position of the Campydoridae remained 'uncertain'. This uncertainty was primarily due to the absence of pharyngo-intestinal 'glands' in Campydora; presence of these structures is characteristic of most Nygolaimidae, and they also occur in some aporcelaim taxa, as well as in some members of the presumably ancestral Bathyodontina Siddiqi, 1983(Coomans & Loof, 1970. ...
The 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.
... Recent workers on the Mononchoidea such as Coomans & Lima (1965), Jensen &Mulvey (1967), andJairajpuri (1969) have not distinguished the single adcloacal supplement. In their brief diagnosis of the Dorylaimida, including some superfamilies, Coomans & Loof (1970) refer to adcloacal supplements only in the suborder Diphtherophorina, for which they state "without paired adanal supplements". ...
Syntypes of Amphidelus tasmaniensis (Allgén, 1929) have been examined, and the male is designated lectotype; the species has a typical amphid (not hook‐like), vulva at 63–65%, prodelphic ovary, two midventral supplements, and an adcloacal supplement. This is the first record of an adcloacal supplement in the Alaimina. Amphidelus papuanus Andrássy, 1973 is redescribed from Chatham Island material. It is characterised by relatively large size (L = 1.2–1.7 mm), posterior vulva (67–70%), prodelphic ovary, three midventral supplements, and a small terminal spine on the tail.
... The number, shape, and position of pharyngeal glands, and especially the position of their nuclei and outlets, are important features to establish phylogenetic relationships among nematodes at several taxonomic levels (2,4,5,10,13). Typically, nematodes have three or five pharyngeal glands (one dorsal and one or two pairs of ventrosublateral glands). ...
In this study an attempt was made to determine the position of the outlets and nuclei of the pharyngeal glands in four monhysterid genera. Five Eumonhystera spp., seven Monhystera spp., and eight Monhystrella spp. were studied under the light microscope. Longitudinal sections of an undescribed Monhystera sp. and cross sections of Geomonhystera disjuncta were also studied under the scanning and transmission electron microscope, respectively. The results of the light microscopic studies were inconclusive about the position of the outlets but showed a number of nuclei in the basal part of the pharynx. The scanning and transmission electron microscopic studies revealed five pharyngeal glands and their outlets; their position was as follows: dorsal gland outlet at the base of buccal tooth, first pair of ventrosublateral gland outlets halfway along the pharynx, and second pair of ventrosublateral gland outlets close to the base of the pharynx. It is concluded that at least three, and possibly five, nuclei are in the basal part of the pharynx. This pattern, in the position of the outlets and nuclei, is similar to that in Caenorhabditis elegans (Maupas, 1900) Dougherty, 1953 and may well be the basic plan in the Class Chromadorea (including Secernentia as a subclass).
A catalogue is presented of the nematode slide collection of W.L. Nicholas, which is deposited in the National Research Collections Australia at CSIRO. This is the most extensive slide collection of free-living marine and estuarine nematodes from Australia to date, and consists of 553 putative species, collected across a wide range of Australia’s eastern and northern regions over the course of nearly 40 years. The collection contains mostly marine and estuarine free-living nematodes collected on coarse substrate in littoral habitats. The most abundant genera were Desmodora, Theristus, and Onyx. Most taxa were found rarely, being recorded only once, and repeated sampling at several sandy beach sites revealed only a small proportion of the fauna on more than one occasion. A significant proportion of the taxa were also found to be widespread, occurring on more than one occasion at more than one location, with Theristus sp., Onyx sp., and Viscosia sp. occurring in the greatest number of localities. The catalogue adds an additional 90 species and 160 genera to the documented fauna of Australian free-living nematodes verifiable by specimens in permanent collections. It thus provides a better framework for studying nematode biodiversity and biogeography in the region.
A classification of the entire Phylum Nematoda is presented, based on current molecular, developmental and morphological evidence. The classification reflects the evolutionary relationships within the phylum, as well as significant areas of uncertainty, particularly related to the early evolution of nematodes. It includes 3 classes, 8 subclasses, 12 superorders, 32 orders, 53 suborders, 101 superfamilies, 276 families, 511 subfamilies, 3030 genera, and 28537 species. All valid species named from the time of publication of the previous classification and census (2010) to the end of 2019 are listed, along with the number of valid species in each genus. Taxonomic authorities are provided for taxon names of all ranks. The habitats where the species in each genus are found are listed, and an alphabetic index of genus names is provided. The systematics of nematodes is reviewed, along with a history of nematode classification; evolutionary affinities and origins of nematodes; and the current diagnosis of the group. Short overviews of the general biology, ecology, scientific and economic importance of the group are presented.
The present review has documented a list of keys for identifying plant-parasitic nematodes at different taxonomic levels including superfamily, family, subfamily, genus, and species. It was compiled as a current source of information to assist students and professionals in the discipline of nematology for identification of this important group of soil nematodes.
Nematodes that transmit viruses to plants are known to occur only in two suborders of the order Dorylaimida class Adenophorea whereas most other plant parasitic nematodes are in the order Tylenchida class Secernentea. Plant parasitism seems to have developed independently in these two classes. Maggenti (18) suggests that the Adenophorea are the older group and that within the Dorylaimida there are two relatively recent divergent lines; one containing the genera Longidorus, Paralongidorus and Xiphinema, some species of which transmit nepoviruses (see Taylor and Robertson in these Proceedings), is in the family Longidoridae, suborder Dorylaimina. The other line containing the genera Trichodorus and Paratrichodorus, some species of which transmit tobraviruses, is in the family Trichodoridae, suborder Diphtherophorina. Although species of Paralongidorus have not so far been implicated as virus vectors their morphology is so similar to Longidorus that it is probably prudent to treat them as potential virus vectors.
Longidorids are moderate to long (L varies from about 1.5 mm to about 13 mm), relatively slender, sluggish nematodes. Their general body shape, upon relaxation by gentle heat, is usually ventrally arcuate to C-shaped or spiral, rarely straight; the curvation is more pronounced towards the tail, especially in males. The anterior end (lip region) may be continuous with the body or offset to a variable extent. The tail is usually short, hemi-spheroid or conoid, with or without a peg; it may also be elongate conoid and even long and filiform. The variation in tail shape is largest in the genus Xiphinema. All representatives possess a very long spear used for puncturing plant cells on the contents of which they feed.
Members of Diphtherophorina were first described by de Man in 1880/1884 (27,28). At that time it was customary to include all spear-bearing nematodes with a bottle-shaped oesophagus not containing a valvular apparatus, in the genus Dorylaimus Dujardin, 1845. De Man described a species Dorylaimus primitivus, which nowadays is considered a Trichodorus. In the same papers he described the new genus Diphtherophora with the single species D. communis. It was chiefly the peculiar characters of the cuticle and the complicated spear, as well as the shape of the oesophagus, which made him exclude this species from Dorylaimus.
Summary Morphological structures for identifying freshwater nematodes, e.g. buccal cavity, sensory receptors, oesophagus, reproductive organs and tail are described. Most freshwater nematodes belong to the Adenophorea and are characterised by the presence of setae, adhesive glands and conspicuous amphids. Methods for collecting nematodes from the sediments of running water (e.g. corer, pumps), within plants and aufwuchs are listed. Methods for fixation, extracting and preparing nematodes for identification are described. Life history parameters (e.g. generation time, eggs per female) are not available for lotic nematodes but are summarised for free-living nematodes in soil, lakes and seas. Field studies indicate that, in contrast to laboratory experiments with nematode cultures, many species will have a generation time of several months. Abundance and species diversity of nematodes of lotic habitats are provided; more than 100 nematode species inhabit lotic habitats and densities can reach 230 individuals per ml. Links between meiobenthic nematodes and the micro- and macrobenthos are unclear at present. Evidence such as the increased bacterial activity due to nematode grazing suggests that such interactions may be significant.
Five species of Mononchida and Mononchulus nodicaudatus (v. Daday, 1899) Cobb, 1918 are reported from freshwater sediments at or near Boba Island, Okavango Swamps, Botswana. Illustrations are given for Mylonchulus lacustris (Cobb N.A. in Cobb MX, 1915) Andrssy, 1958, Iotonchus risoceiae (Carvalho, 1955) Andrssy, 1958 and Cobbonchus spec. Two species of Mononchus Bastian, 1865, M. aquaticus Coetzee, 1968 and M. truncatus Bastian, 1865 were also found. The usually rare species M. nodicaudatus was well represented and its juvenile stages are described for the first time.
In order to validate the results of biomarkerstudies as tools for the assessment of smallstreams, the meiofauna community and inparticular the nematodes of two small Germanstreams (Baden-Wrttemberg) were analysedduring 1998. One site of Krhenbach (AB)and three sites of Krsch (KA, KD, KE) weresampled in March, May, July and November. Thelimnological analysis indicates that two sitesof Krsch (KD, KA: polluted sites) weredistinctly enriched by inorganic and organicsubstances compared with KE and AB (unpollutedsites). In the Krhenbach, nematodes,chironomids, oligochaetes and tardigradesdominated the meiofauna community (92%),whereas in the Krsch nematodes andoligochaetes were dominant (93%). The totalmeiofauna density showed seasonal patterns inboth streams. Nematodes were the most abundantgroup at the four investigated locations. Themean abundance of nematodes ranged from 28individuals per 10 cm2 to 1205 individualsper 10 cm2 and at least 103 species wereidentified, belonging to 25 families. Nosubstantial difference occurred in thedistribution of nematode feeding-types at thepolluted and unpolluted sites. All communitieswere clearly dominated by bacteria-feedingnematodes with percentages ranging from 70% to75%. In order to assess the sediment quality,the nematode community of each sampling sitewas interpreted using the ratio ofSecernentea/Adenophorea as well as the MaturityIndex (MI). Both the percentage of Adenophoreaand the MI decreased towards the pollutedsites, detecting a more disturbed nematodecommunity at the polluted than unpollutedsites. However, there are nematode species(e.g. Tobrilus diversipapillatus) whichdo not fit in this assessment concept. In thisstudy the disturbance of the nematode communitywas related to eutrophication, rather than tothe effect of contaminants. In summary, thisinvestigation confirmed that meiofaunaorganisms and in particular nematodes aresuitable for the assessment of the sedimentquality of running waters.
Keys are given for the identification of species in the Trichodoridae, partly based on the keys of Loof (1975) and Siddiqi (1974). Recent additions are included and for al1 species a drawing is given of the structure referred to in the key. The genus Paratrichodorus and the diagnostic value of the subgenera Paratrichodorus, Atlantadorus and Nanidorus are discussed. R É S U M B Systématique des Trichodoridae (Nematoda) et clés de détermination des espèces L'auteur propose de nouvelles clés de détermination des espèces de Trichodoridae fondées sur les clés de Loof (1975) et de Siddiqi (1974), et tenant compte des données les plus récentes. Des illustrations sont fournies pour les caractères les plus importants de chaque espèce. Le genre Paratrichodorus et, la,valeur des sous-genres Paratricho-dorus, Atlantadorus et Nanidorus sont discutés. The Trichodoridae are economically, a very important group of nematodes as ectoparasites on the roots of many crop plants and as vectors of tobacco rattle virus and pea early browning virus. Despite the ease with which nematodes can acquire viruses from plants there are rela-tively few vectors. Of some 35 species of Tricho-doridae, a t least eleven transmit tobra-viruses (Hooper, 1973), so identification to species level may be very important. During my study on Trichodoridae 1 came across several inadequacies in available descrip-tions and keys; these changes, together with recent additions made it necessary t o modify the Beys of Loof (1975) and Siddiqi (1974). For al1 the species 1 have included a drawing of the structure referred to in the key.
ResearchGate has not been able to resolve any references for this publication.