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At least 19 recordsLinked to original sources
PubMed1998

An annotated checklist by genus and species of 93 species level names for 51 recognized species of small strongyles (Nematoda: Strongyloidea: Cyathostominea) of horses, asses and zebras of the world.

The results of an international collaborative effort to prepare a recommended list of scientific names for the small strongyles (Nematoda: Strongyloidea: Cyathostominea) of horses, donkeys and zebras are reported. Fifty-one valid species are recognized in 13 genera, including Cyathostomum, Coronocyclus, Cylicodontophorus, Cylicocyclus, Cylicostephanus, Skrjabinodentus, Tridentoinfundibulum, Petrovinema, Poteriostomum, Parapoteriostomum, Hsiungia, Cylindropharynx and Caballonema. In addition, 42 other species level names are listed as synonyms of the 51 recognized species or as species inquirendae (10 species) or nomen nudum (one species). Numerous annotations provide information on the nomenclatural and systematics history, current status and additional studies needed.

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PubMed1979

Species of Cloacina Linstow, 1898 (Nematoda: Strongyloidea) from the black-tailed wallaby, Wallabia bicolor (Desmarest, 1804) from eastern Australia.

Species of Cloacina Linstow, 1898 (Nematoda: Strongyloidea) are reported and/or described from the stomach of the macropodid marsupial Wallabia bicolor (Desmarest, 1804) collected in eastern Australia. Nematodes were examined from 26 hosts collected in 3 states and the number of species of Cloacina in any one host was 2--7. The following species were encountered: C. wallabiae Johnston and Mawson, 1939, C. gallardi Johnston and Mawson, 1940, C. edwardsi Mawson, 1972 and C. cornuta (Davey and Wood, 1938) the last named constituting a new host record. The following new species are described: C. mawsonae sp. nov., C. papillata sp. nov., C. annulata sp. nov., C. castor sp. nov. and C. pollux sp. nov.

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PubMed1994

Cyclodontostomum purvisi (syn. Ancistronema coronatum) (Nematoda: Strongyloidea: Chabertiidae) from rats of Kalimantan and Sulawesi, Indonesia.

Cyclodontostomum purvisi Adams, 1933 (Nematoda: Strongyloidea: Chabertiidae) was collected from the ceca of Maxomys whiteheadi, Leopoldamys sabanus, and Niviventer cremoniventer of East Kalimantan and Eropeplus canus, Paruromys dominator, and Rattus hoffmanni (Rodentia: Muridae: Murinae) in South Sulawesi, Indonesia. Kalimantan and Sulawesi are new localities for this nematode, and each of the Sulawesian rats are new hosts. Presence of the external corona radiata consisting of 8 bifid elements was confirmed in Cyclodontostomum. Ancistronema coronatum Smales, 1992 is synonymized with C. purvisi. The cephalic end of Kalimantan specimens tilted dorsally more strongly than C. purvisi from Sulawesi. Cyclodontostomum purvisi seems to have a wide host range in the Murinae, being distributed widely in the area from India to Australia.

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PubMed1994

Coronocyclus ulambajari n. sp. (Nematoda: Strongyloidea) from horses of Mongolia.

Coronocyclus ulambajari n. sp. (Strongyloidea: Cyathostominae) from horses of Mongolia is described. The external leaf-crown (ELC) of the new species consists of 28 elements and the internal leaf-crown (ILC) of approximately 80 elements. A spindle-shaped (in optical section) mouth collar support is separated anteriorly from the buccal capsule and connected to it and elements of leaf-crowns by bundles of connective tissue. The buccal capsule is cylindrical, circular in cross-section, and approximately 3 times as wide as deep. A large, tongue-like dorsal cone protrudes from the floor of the buccal capsule overlying the large dorsal esophageal tooth. The duct of the dorsal esophageal gland opens at the tip of the dorsal cone. The tail and vagina of females are short, and the vulva is close to the anus. The buccal capsule and dorsal cone are most similar to Coronocyclus labratus, but differ significantly in size of dorsal cone and relative width and depth of the buccal capsule as well as characteristics of the leaf-crowns and female reproductive systems.

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PubMed2001

Mutation scanning analysis of sequence heterogeneity in the second internal transcribed spacer (rDNA) within some members of the Hypodontus macropi (Nematoda: Strongyloidea) complex.

Single-strand conformation polymorphism analysis was employed to investigate sequence variation in the second internal transcribed spacer (ITS-2) of nuclear ribosomal DNA within and among individuals representing three operational taxonomic units (OTUs) of Hypodontus macropi from different species of Australian macropodid marsupials. Of the 96 nematodes analysed, totals of 3 (OTU1 from Petrogale persephone), 10 (OTU2 from Macropus robustus) and 7 (OTU9 from Macropus rufus) representative individuals were selected for DNA sequencing to characterise and estimate the magnitude of nucleotide variation in the ITS-2. While no unequivocal nucleotide difference in the ITS-2 was detectable within OTU1, most sequence variation (3/44.7%) detected within OTU2 and OTU9 was related chiefly to dinucleotide (CA, TA, or a combination of both) differences. This microsatellite variability in some H. macropi OTUs suggests that the ITS-2 rDNA may be subjected to slippage events during DNA replication, resulting in short dinucleotide repeat tracts being dispersed throughout the ITS-2 lineages, or possibly transposition and/or crossing-over events. Nucleotide variation in the ITS-2 of individual OTUs was related to the proposed secondary structure for the precursor ribosomal RNAs. Most of the sequence heterogeneity or polymorphism within OTU2 and OTU9 occurred in loops or bulges of the predicted secondary structure, which appear not to be under functional constraint. The findings of this study have implications for investigating speciation events and population differentiation in nematodes at the molecular level.

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PubMed1993

Sibling species within Macropostrongyloides baylisi (Nematoda: Strongyloidea) from macropodid marsupials.

Macropostrongyloides baylisi from four different species or subspecies of host were analysed electrophoretically at 27 enzyme loci. The results revealed the existence of two species, one in Macropus giganteus and the other in M. robustus robustus, M.r. erubescens and M.r. parryi, that had fixed genetic differences at 33% of loci. Populations of nematodes from two subspecies of M. robustus, M.r. robustus from Queensland and M.r. erubescens from South Australia, had fixed genetic differences at two (7.4%) of 27 loci and were considered to belong to the same species. No fixed genetic differences were detected between nematodes from M. parryi and M.r. robustus. A discriminant function analysis of morphological data assigned 96% of specimens to groups defined on the basis of the host species or subspecies from which they were obtained. This separation of Ma. baylisi into host-specific groups did not, however, totally correlate with the electrophoretic data. The species of M. baylisi in M. giganteus was genetically more distinct from the sibling species in M. robustus/M. parryi than to a related but morphologically dissimilar nematode, Ma. yamagutii from M. fuliginosus. This suggests an evolutionary parallel between host and parasite at the genetic level which is not reflected by morphological differences.

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PubMed1995

Differences in a ribosomal DNA sequence of morphologically indistinguishable species within the Hypodontus macropi complex (Nematoda: Strongyloidea).

The nucleotide sequence of the second internal transcribed spacer (ITS-2) from ribosomal DNA has been determined for 3 members of the Hypodontus macropi species complex. Sequences were compared from nematodes collected from 3 species of Australian macropodid marsupial, Petrogale persephone, Macropus robustus robustus and Thylogale billardierii. The ITS-2 of each operational taxonomic unit ranged from 287 to 292 bases in length, and had a GC content of 36.6-40.1%. Differences in nucleotide sequence between nematodes from the different host species ranged from 25.0% to 28.3%. The data suggest that H. macropi from P. persephone represents a different species to those in M. r. robustus and T. billardierii. The unique feature of this study is that it represents a comparison of the ribosomal DNA sequences of nematode species which are morphologically indistinguishable but which have been demonstrated to be genetically distinct (i.e. cryptic) species based on electrophoretic data. The results also demonstrate further that morphological characters alone are often not adequate for species recognition. Differences between these 3 species of H. macropi in their recognition sites for restriction endonucleases, indicates that a PCR-RFLP approach could be used, in conjunction with allozyme electrophoresis, to establish how many species are present within the H. macropi complex.

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PubMed1992

Detection by allozyme electrophoresis of cryptic species of Hypodontus macropi (Nematoda: Strongyloidea) from macropodid marsupials.

Allozyme electrophoresis of 98 Hypodontus macropi from eight different species of hosts using 24 enzymes revealed a complex of at least six sibling species, with 15-50% fixed genetic differences between taxa. Except for the taxon parasitizing Macropus rufus/M. robustus, pairs of parasite taxa were, in each case, sympatric at each locality examined, thus supporting the conclusion that they represent valid species. The existence of a series of host-specific nematode taxa explains many of the inconsistencies noted previously in the host distribution of H. macropi. Comparison of parasite allozyme phenograms with host phylogeny suggests that four of the speciation events could be attributable to cospeciation and two to host switching. A clear case of host switching between M. rufus/M. robustus and M. fuliginosus was found.

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PubMed1997

Evidence for hybridisation between Paramacropostrongylus iugalis and P. typicus (Nematoda:Strongyloidea) in grey kangaroos, Macropus fuliginosus and M. giganteus, in a zone of sympatry in eastern Australia.

Specimens of Paramacropostrongylus iugalis and P. typicus, collected from eastern (Macropus giganteus) and western (M. fuliginosus) grey kangaroos in New South Wales and Queensland, were examined morphologically and electrophoretically at 4 enzyme loci previously demonstrated to be diagnostic between the 2 species. Collections of P. iugalis from M. giganteus from outside the zone of sympatry of the 2 kangaroo species conformed electrophoretically and morphologically with previous studies. Within the zone of sympatry, the 2 nematode species were distinguishable electrophoretically, with most P. iugalis occurring in M. giganteus and all P. typicus occurring in M. fuliginosus. Some specimens of P. iugalis were identified in M. fuliginosus and, in both host species, nematodes were encountered with electrophoretic profiles intermediate between P. iugalis and P. typicus. The frequent occurrence in these specimens of heterozygotes suggested that the genetic barriers between the 2 nematode species were not complete and that genetic interchange (i.e. hybridisation) was occurring.

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PubMed1997

An electrophoretic analysis of patterns of speciation in Cloacina clarkae, C. communis, C. petrogale and C. similis (Nematoda:Strongyloidea) from macropodid marsupials.

An electrophoretic study was conducted on Cloacina clarkae, C. communis, C. petrogale and C. similis based on 19 enzyme loci. C. communis was widely distributed in Macropus robustus, showing some genetic variation among populations but occasionally switching to other macropodid hosts (M. agilis, M. antilopinus). C. similis occurred in members of the Petrogale penicillata complex, Macropus dorsalis and Thylogale billardierii, but showed no evidence of genetic differentiation in spite of its occurrence in different host species and in geographically distinct regions of Australia. C. clarkae from Macropus eugenii was genetically indistinguishable from C. similis and was considered synonymous with it. C. petrogale occurred in a similarly diverse range of hosts and geographical regions to C. similis, but was represented electrophoretically as 4 distinct genetic species, 1 in Petrogale assimilis, a second in P. lateralis purpureicollis, a third in Macropus parryi in Queensland and a fourth in M. eugenii in South Australia. Although the host and geographical ranges of C. similis and C. petrogale are analogous, the genetic uniformity of the former and diversity of the latter illustrate the incomplete understanding we have of the immediate causes of speciation in nematodes.

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PubMed1984

An SEM study of the cephalic region, buccal cavity and male tail of the species of the genus Strongylus Müller, 1780 (Nematoda, Strongyloidea).

The four species of the genus Strongylus Müller, 1780, namely, S. equinus, S. edentatus, S. vulgaris and S. asini were examined with the scanning electron microscope (SEM). The buccal cavity of each species was cut transversely and longitudinally and the scanning electron micrographs illustrate the shape of the buccal cavity and the dorsal gutter. The micrographs also show the presence of denticles near the oral rim of the buccal cavity of S. edentatus and the shape of the teeth in the buccal cavity of S. equinus, S. vulgaris and S. asini. The bursa of the four species has three symmetrical lobes, one dorsal and two lateral. The length of the three lobes in relation to each other varies between the species. The genital cone has a single large ventral papilla, a pair of dorsal raylets, a median dorsal cuticular appendage and a variety of cuticular appendages lateral and ventral to the cloaca. The development and arrangement of these components differs between the four species of the genus and can be used as a supportive character for specific identification.

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PubMed1999

Rugonema labiatum n. g., n. sp. (Nematoda: Strongyloidea) from the stomach of Macropus irma (Marsupialia: Macropodidae) from Western Australia.

Rugonema labiatum n. g., n. sp. is described from the stomach of Macropus irma (Jourdan) from Western Australia. The new genus possesses four branches to the dorsal ray, has a cylindrical buccal capsule and lacks a cervical groove, placing it within the subfamily Cloacininae Stossich, 1899. The presence of a prominently striated buccal capsule and labial as well as cephalic collars places the genus within the tribe Pharyngostrongylinea Popova, 1952, but it is distinguished from all existing genera within the tribe by the possession of four lips. The presence of lips is an important characteristic of the related tribe Zoniolaiminea (Popova, 1952) and the characters used in distinguishing these two tribes are discussed.

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PubMed1981

[Peramelistrongylus Mawson, 1960 and Profilarinema n. gen., trichostrongyloid nematodes apparently transitional between the Strongyloidea and the atypical genus Filarinema Mönnig, 1929 (author's transl)].

Peramelistrongylus skedastos Mawson, 1960, type species of the genus Peramelistrongylus Mawson, 1960 is redescribed. Also described is Profilarinema hemsleyi n. gen., n. sp. from Trichosurus vulpecula in Western Australia. The new genus, which is similar to Filarinema, differs from it essentially by the absence of the complex buccal armature which characterizes the latter genus. The genera Batrachostrongylus Yuen, 1963, parasitic in amphibians, Peramelistromgylus, parasitic in perameloid and dasyuroid marsupials, Profilarinema parasitic in phalangerid marsupials and Filarinema Mönnig, 1929, parasitic in macropodid marsupials, seem to us to constitute a homogeneous evolutionary line distinct from the other Australian trichostrongyloids.

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PubMed1986

[Type identity of the swine parasites Globocephalus longemucronatus and G. urosubulatus (Nematoda, Strongyloidea)].

On the basis of a critical analysis of the literature and of our own investigations, it is pointed out that the two hookworm species known from European swine, namely Globocephalus longemucronatus Molin, 1861 and G. urosobulatus (Alessandrini, 1909), are identical. All the differences hitherto used to distinguish these species are shown to be due to incorrect descriptions of the taxonomic characters or to misinterpretations of statements made by former authors. Accordingly, only one species of Globocephalus occurs in Europe, which has to be named G. longemucronatus Molin, 1861, with Crassisoma urosubulatum Alessandrini, 1909 as its junior synonym. A short diagnosis of this species is given.

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PubMedDate not supplied

[Mechanism of distribution of Strongyloidea larvae among ungulate animals at pasture].

The problem of dissimilation of larvae of strongylates of ruminants in pasture biocoenosis is discussed. A new form of their migration in horizontal direction on the basis of negative geotaxis is suggested. As a result of alternation of vertical migration of larvae on the tilting leaves of the grass and their subsequent washing off with rain or dew down on the ground proceeds their distribution on the pasture. The description of corresponding experiments is given.

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