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1.
Paragordius tricuspidatus (Dufour, 1828) and Spinochordodes tellinii (Camerano, 1888) are two sympatric species of horsehair worms in southern France. Paragordius tricuspidatus was found in only one host species, Nemobius sylvestris (Bosc, 1792), while Spinochordodes tellinii was found in nine different hosts belonging to Orthoptera Caelifera. Size of nematomorphs varied strongly, but is additionally influenced by host size (in Spinochordodes tellinii) or number of parasites per host (in Paragordius tricuspidatus). Both species have a clear seasonality with Paragordius tricuspidatus occurring from June to early August and Spinochordodes tellinii occurring in August and September.  相似文献   

2.
The parasitic Nematomorph hairworm, Spinochordodes tellinii (Camerano) develops inside the terrestrial grasshopper, Meconema thalassinum (De Geer) (Orthoptera: Tettigoniidae), changing the insect's responses to water. The resulting aberrant behaviour makes infected insects more likely to jump into an aquatic environment where the adult parasite reproduces. We used proteomics tools (i.e. two-dimensional gel electrophoresis (2-DE), computer assisted comparative analysis of host and parasite protein spots and MALDI-TOF mass spectrometry) to identify these proteins and to explore the mechanisms underlying this subtle behavioural modification. We characterized simultaneously the host (brain) and the parasite proteomes at three stages of the manipulative process, i.e. before, during and after manipulation. For the host, there was a differential proteomic expression in relation to different effects such as the circadian cycle, the parasitic status, the manipulative period itself, and worm emergence. For the parasite, a differential proteomics expression allowed characterization of the parasitic and the free-living stages, the manipulative period and the emergence of the worm from the host. The findings suggest that the adult worm alters the normal functions of the grasshopper's central nervous system (CNS) by producing certain 'effective' molecules. In addition, in the brain of manipulated insects, there was found to be a differential expression of proteins specifically linked to neurotransmitter activities. The evidence obtained also suggested that the parasite produces molecules from the family Wnt acting directly on the development of the CNS. These proteins show important similarities with those known in other insects, suggesting a case of molecular mimicry. Finally, we found many proteins in the host's CNS as well as in the parasite for which the function(s) are still unknown in the published literature (www) protein databases. These results support the hypothesis that host behavioural changes are mediated by a mix of direct and indirect chemical manipulation.  相似文献   

3.
A comparative analysis of parasite communities in the grayling and minnow has been performed. These communities differ in the number of constituent species and in the fact that the community of the minnow is dominated by one allogenic species, whereas that of the grayling usually has two dominants, both being autogenic species. The values of species diversity indices characterizing these communities are also different. Differences between the parasite communities of these fish species reflect the position of their hosts in the hydrobiocenosis. Species prevailing in both communities are classified as specialists, which is characteristic of parasite communities of the boreal-piedmont faunal complex. Both these communities consist of three species groups distinguished by their proportions in the total biomass, which indicates that parasitic communities are structured in a certain way and that the distribution of species in them is not random.  相似文献   

4.
《Nordic Journal of Botany》2007,25(3-4):245-254
A number of benthic microfauna samples collected in Sardinia in the 1970s, and screened for the occurrence of microalgae in the 1990s, revealed some remarkable desmid species. Most of these species could not be found in a series of samples collected in 2006. Eleven desmid taxa are discussed in detail, two of which are described as new to science; Cosmarium majaeforme sp. nov. and Xanthidium sardiniense sp. nov. The specific composition of the Sardinian desmid flora is discussed both in relation to the prevailing environmental conditions and to its geographic position close to the African continent.  相似文献   

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7.
The Sacoglossa (= Ascoglossa) comprise a ‘complete’ evolutionary series from species with a large shell into which the animal can withdraw completely, through species with a reduced shell covering only the visceral mass, to shell-less (‘nudibranchiate’) forms some of which have lateral wing-like extensions, parapodia, others bearing leaf-like or cylindrical dorsal appendages, cerata. The Sacoglossa are all specialized suctorial feeders, and almost all are stenophagous herbivores. Hence many anatomical adaptations to a particular food occur in the alimentary system. However, a number of characters seem to reflect phylogenetic relationships as well. Among these are presence/absence, shape, and position of pharyngeal pouches, basic shape of radular teeth, branching pattern of digestive gland, and position of anus. The classificatory significance of these characters is discussed.  相似文献   

8.
Phillips  L.E.  Nelson  W.A.  & Kraft  G.T. 《Journal of phycology》2000,36(S3):54-55
The genus Lenormandia is composed of nine species from Australia and New Zealand. Some of the these are well known, but others are rare, obscure and ill-defined. We have examined material of all described species and found that they fall into two discrete groups that differ in apex morphology and position of reproductive structures. Plants of the first group, containing the type species L. spectabilis , have a cleft apex and reproductive structures produced directly on the blade surface, whereas those of the second group have a strongly inrolled apex and produce reproductive structures dorsally on small branchlets which arise either from the margins or the midrib. The groups were also found to form discrete clades on analysis of 18S rRNA sequences. All the members of the first group are endemic to Australia, whereas the second group, designated by the new genus name Adamsiella , contains two previously described New Zealand species and a single Australian representative. In addition, two new species are described in this group from New Zealand. Members of the closely related genus Lenormandiopsis were also examined and the type species, L. latifolia , was found to conform in apex morphology and position of reproductive structures to the genus Lenormandia. Accordingly Lenormandiopsis has been subsumed within Lenormandia. The remaining three members of the former genus Lenormandiopsis , however, were found to differ from both the type species and the genus Lenormandia and consequently have been transferred to the separate genus Geraldia , along with a new species from Geraldton, Western Australia which is designated as the type.  相似文献   

9.
Abstract
Priamima , a new genus of Corylophidae from east Australia, is described, based on a single species, P. rubicunda (Macleay), which was previously described as a nitidulid. The species is redescribed and figured. A key to the world genera of the tribe Orthoperini is included, and the phylogenetic position of Priamima is discussed. Little is known about the biology of this species, but specimens have been taken from ants' nests.  相似文献   

10.
Several stages of the copepodBasipodella harpacticola n. gen., n. sp., which lives as a parasite on harpacticoid copepods, are described on the basis of four individuals obtained from the Peruvian deep-sea. The taxonomic position of the new species is discussed.  相似文献   

11.
A karyological analysis was carried out on different European species of the genus Hydromantes (Plethodontidae). All the species examined share the same chromosome number (2n=28) and, with the exception represented by pair XIV, morphologically similar karyotypes. While the karyotypes display a similar distribution — mainly centromeric and pericentric — of C-heterochromatin, quantitative variations in pericentric heterochromatin are observed among species. In the continental species Hydromantes italicus and ambrosii as well as in the eastern Sardinian species imperialis, flavus and specie nova, pair XIV consists of heteromorphic sex chromosomes of the XX/XY type. It is proposed that the differentiation of the Y might have taken place through the occurrence of a structural rearrangement, such as a pericentric inversion, starting from a hypothetical, homomorphic pair XIV. A sex-related heteromorphism is not found in the western Sardinian species H. genei. A further karyological differentiation among these species concerns the position of the nucleolus organizing region (NOR), which is located on chromosome XII (H. italicus and ambrosii) or on chromosome X, close to the centromere (H. genei, H. imperialis and H. specie nova), or in an intercalary position (H. flavus). The location and the number of the 5 S DNA sites have been conserved during species divergence. On the basis of these karyological data, as well as of results obtained through a preliminary restriction enzyme analysis of the ribosomal and genomic DNAs, the phyletic relationships among the European Hydromantes species are discussed.  相似文献   

12.
Molecular analysis of mitochondrial cytochrome b sequences from 159 species of the family Cyprinidae supports the subfamily Danioninae, of which Rasborinae is shown to be a junior synonym. Analysis of combined cytochrome b and a fragment of the nuclear rhodopsin gene from 68 species, including 43 species representing the subfamily Danioninae, supports phylogenetic distinctness of Danio and Devario. In the combined molecular analysis Microrasbora rubescens, Chela, Laubuca, Devario, and Inlecypris form a clade with M. gatesi , M. nana and M. kubotai being in sister group position to the rest. The sister group of this Devario clade is Danio . Inlecypris is synonymized with Devario. Microdevario, new genus, is proposed for M. gatesi , M. nana and M. kubotai , supported by morphological characters. In the cytochrome b analysis, M. rubescens falls outside Devario , and there is no morphological support for including M. rubescens in Devario . In the cytochrome b analysis Esomus  +  Danionella is the sister group of Danio and Devario clades, whereas in individual rhodopsin and combined analyses Esomus is the sister group of Danio , and of Danio and the Devario clade, respectively. Sundadanio presents at least one strong morphological synapomorphy with Danio , but is positioned in molecular trees either as a member of the Cyprininae or as sister group of the remaining Danioninae. In the morphological analysis, small-sized species grouped together based on shared reductions that are not necessarily synapomorphies. In the molecular analysis, small-sized species such as Danionella and Sundadanio possess long branches and their position varies, but they did not group together. This suggests morphological homoplasy, but phylogenetic positions are not well supported in the molecular analyses  相似文献   

13.
G Manilla 《Parassitologia》1990,32(2):265-274
The soft tick of the coniceps-capensis group, Ornithodoros (Alectorobius) maritimus Vermeil & Marguet, 1967, is reported for the first time in Italy. Besides the systematic position and the distribution of the species, as well as observations on bird hosts, the biology and pathogenic role of the group species are discussed.  相似文献   

14.
Steciow MM 《Mycologia》2003,95(5):934-942
Brevilegnia ensenadensis sp. nov. is described from litter (floating twigs, leaves, and roots) in a man-made, polluted channel near a petroleum refinery, in Buenos Aires Province, Argentina. The species is illustrated and compared with other species of the genus; it can be identified by the preponderance of smooth or papillate oogonia, with a distinctive irregular inner wall, borne in bent or coiled oogonial stalks, which are terminal, lateral or of the intercalary position. The oogonia often are irregular in shape, and the oospheres mostly are immature. The single oospore is eccentric inside the great oogonia, and the species develops mainly diclinous antheridial branches and has fewer monoclinous and androgynous ones.  相似文献   

15.
Cordyceps cuncunae Palfner sp. nov. is reported from Valdivian rainforest in southern Chile, parasiting larvae of an unidentified ghost moth species (Lepidoptera, Hepialidae) which probably feed on roots of Laureliopsis philippiana. Morphology and anatomy of stromata as well as morphological and molecular characteristics of mycelium in pure culture which produces two anamorphs, one of them Lecanicillium-like, are described. The systematic position of the new taxon within the most recent generic concept is discussed. This is the first record of an endemic Cordyceps species from Chile.  相似文献   

16.
A bisexual population of Potamocypris villosa, found in Lago de Encina, a mesotrophic lake in the Cantabrian mountains, NW Spain, is the first certain record of the male of this species. Valves and soft parts are described. Males of Potamocypris-species lack a furca although a rudimentary furca is always present in females. The same applies to species of related genera, such as Tanganyikacypridopsis and Plesiocypridopsis. Some remarks on the position of the genus Potamocypris in the Cyprinopsinae are presented.  相似文献   

17.
Cythere japonica was proposed by Hanai (1959) as a new species of the genus Cythere , from the Pleistocene Sawane Formation in Sado Island, Niigata Prefecture, Japan. The characters of carapace were already known, but the appendages have not been previously described. The authors formerly considered that this species should be separate from the genus Cythere sensu stricto because it has twice as many sieve-type pore systems as typical Cythere species, and a markedly higher carapace. The existence of living Cythere japonica in the tidal zone of north-west Japan is confirmed, and its taxonomic position re-examined on the basis of its appendages and the ontogeny of pore systems. The appendages, except for the copulatory organ, are almost identical with those of other Cythere species, and their pore systems share the same pattern in and before the A-4 moult stage. On the basis of these features this species should be retained in the genus Cythere. Phylogenetic relationships are considered on the basis of the ontogeny of pore systems.
The abdominal segments of podocopid Ostracoda, which have always been regarded as difficult to observe because of their fusion, are shown clearly by the SEM.  相似文献   

18.
Until recently, all papillated specimens of Pareledone were ascribed to the species Pareledone charcoti (Joubin, 1905), of which P. aurorae (Berry, 1917) was considered a junior synonym. Re-examination of the papillated type material of Pareledone, coupled with extensive fishing over several years off the Antarctic Peninsula, has led to a revision of this position. Seven new species of papillated Pareledone are identified from the Antarctic Peninsula region. They are identified by subtle taxonomic characters, such as the morphology and placement of their papillae, although traditional indices often fail to separate the species. Whilst apparently sympatric, there is some evidence of niche separation of these species with respect to depth. A key is provided for their identification.  © 2005 The Linnean Society of London, Zoological Journal of the Linnean Society , 2005, 143 , 75−108.  相似文献   

19.
The genus Vulpicida is monographcd. Its delimitation and nomenclature is revised. The following 6 species are accepted: V. cunudensb, V. juniperinus. V. pinastri, V. tilesii, V. rubulosus and V. viridis . The study includes anatomy, and ontogeny of ascomata, as well as chemical studies. Secondary metabolites was studied with TLC and HPLC, and isozymcs by isoelectric focusing. The ecology. distribution and probahle evolution of the taxa are discussed and compared with other lichens and phorophytes. The systematic position of the genus is investigated by cladistic methods. Keys for the identification of the genus and the species and distrihution maps and photos of the species are included. The new combination Vulpicidu pinustri var. soralifera is made.  相似文献   

20.
All species that have been described of the genera mentioned in the title are listed and their systematic position given. The species of Stilifer (with 11 species, including S. inflatus sp.n. and 5. concavus sp.n.) are parasites of starfishes. Scalenostoma (3 species) are parasites of stone corals. Thyca (with 8 species) is removed from Capulidae, and included in Eulimidae. T. hawaiiensis sp.n. is described. The species of Thyca are parasites of starfishes. The species of Mucronalia (including M. trilineata sp.n.) are probably parasites of ophiuroids and Echineulima (with 4–6 species, including E. ponderi sp.n.) are parasites of echinoids. All species are figured, their characteristics are given and their host species and distributions are listed. Keys are given to the species of each genus, except Mucronalia. The genera Stilimella Laseron and Hyperlia Pilsbry are synonymized with Scalenostoma and the genera Kiramodulus Kuroda, Granulithyca Habe and Bessomia Berry are considered subgenera of Thyca.  相似文献   

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