the nervous system of diplostomum pseudospathaceum niewiadomska, 1984 (trematoda, diplostomidae). iv. nervous system and distribution of sensilla in the daughter sporocyst. 19902217127
[the metacercaria of diplostomum pseudospathaceum niewiadomska, 1984 and diplostomum spathaceum (rudolphi, 1819) in the ocular lens of fish and reactions of the lens to the presence of the parasites]. 19883388863
the nervous system of diplostomum pseudospathaceum niewiadomska, 1984 (trematoda, diplostomatidae). iii. structure of the nervous system in the adult stage.the nervous system of adult diplostomum pseudospathaceum niewiadomska, 1984 was studied using koelle's (1951) method for revealing cholinesterase activity. the nervous system in the fore body grows but its pattern remains the same as in the metacercaria: three pairs of stems connected by numerous commissures and differentiated innervation of various organs in this part of the body. in the elongated hind body the nervous system develops according to another pattern: two pairs of stems connected b ...19873809149
a cysteine proteinase in the cercariae of diplostomum pseudospathaceum (trematoda, diplostomatidae).a cysteine proteinase was detected in extracts from cercariae of the trematode diplostomum pseudospathaceum. the enzyme preferred protein substrates over synthetic, chromogenic peptides. the optimal ph for hydrolysis of substrates was 7.2 for azocoll, 6.4 and 7.6 for azocasein, 7.6 for azoalbumin, and 6.8 for n-benzoyl-l-arginine-4-nitroanilide. elastin-congo red and certain n-blocked l-aminoacyl- and l-peptidyl nitroanilides bearing l-phenylalanine, l-alanine, l-tyrosine, and l-leucine at the p ...19947886037
histochemistry of proteinases in the cercariae of diplostomum pseudospathaceum (trematoda, diplostomatidae).two distinct endopeptidases were detected histochemically in the cercariae of diplostomum pseudospathaceum: a serine proteinase occupying the ceca and a cysteine proteinase occupying the penetration glands. the former was relatively resistant to formaldehyde, required either ca2+ or mg2+ for its stability, and was sensitive to organic fluorophosphate inhibitors but insensitive to thiol-blocking agents. the latter enzyme required both reducing and divalent cation-complexing agents for its full ac ...19947886038
cholinergic and aminergic nervous systems in developing cercariae and metacercariae of diplostomum pseudospathaceum niewiadomska, 1984 (digenea).comparative studies on the cholinergic (chns) and aminergic (ans) nervous systems were carried out in developing cercariae and metacercariae of diplostomum pseudospathaceum. a method for the localization of cholinesterase and nonspecific esterase activities, and the method for the histofluorescence of biogenic amines were used. the first traces of the chns were found in the cercarial embryo, and during growth of the cercaria, the brain ganglia and commissure, as well as anterior and posterior ne ...19968690539
ultrastructure of sensory endings in diplostomum pseudospathaceum niewiadomska, 1984 cercariae (digenea, diplostomidae).using tem techniques, 13 types of sensory endings were revealed on the body and tail of cercariae of d. pseudospathaceum. they differ in the presence or absences of cilia, number of cilia, number of electron-dense rings, basal body type and collar shape. the following groups of sensory endings were distinguished: uniciliate with a short (5 types), moderately long (one type) or long cilium (4 types); multiciliate sensory pits (2 types); and nonciliate sensory bulbs. most sensory endings with long ...19969024865
ultrastructural studies on the sporocyst wall of diplostomum pseudospathaceum niewiadomska, 1984 (digenea, diplostomidae).the sporocyst wall of the daughter sporocyst of diplostomum pseudospathaceum is composed of many elements. it is covered by a syncytial layer of cytoplasm connected to sunken nucleated perikarya (cytons), lying underneath the outer-circular and the inner longitudinal muscle layers. the outer tegumental part forms numerous microvilli covered by glycocalyx and contains many microfilaments, single ribosomes, electron-dense granules and short electron-lucid cisternae. no other cell organelles were s ...19979292308
a protein with lectin activity in penetration glands of diplostomum pseudospathaceum cercariae.homogenates of diplostomum pseudospathaceum cercariae agglutinated mouse erythrocytes. the haemagglutination could be inhibited by certain glycoconjugates containing beta-1,3- and beta-1,4-glycan chains and also by some simple saccharides. the most potent inhibitors were heparin and some other glycosaminoglycans, bacterial lipopolysaccharides, laminarin (a beta-1,3-glucan) and lactulose. after electrophoresis of cercarial proteins, a dominant double band appeared in the 22-24 kda region of gels. ...200111226450
purification and characterization of a saccharide-binding protein from penetration glands of diplostomum pseudospathaceum--a bifunctional molecule with cysteine protease activity.a beta-1,3-glucan-binding lectin from the penetration glands of diplostomum pseudospathaceum cercariae was isolated by affinity chromatography using yeast glucan and curdlan as affinity matrices. further purification to homogeneity was performed by cation-exchange chromatography. the protein migrated as a double band around 24 kda in gels after sds-page. the protein is of strongly basic nature--its pi shown by native ief was around 10. the mass of the protein determined by maldi-tof mass spectro ...200312885190
how a complex life cycle can improve a parasite's sex complex life cycles of parasites are maintained is still a fascinating and unresolved topic. complex life cycles using three host species, free-living stages, asexual and sexual reproduction are widespread in parasitic helminths. for such life cycles, we propose here that maintaining a second intermediate host in the life cycle can be advantageous for the individual parasite to increase the intermixture of different clones and therefore decrease the risk of matings between genetically identi ...200516033580
local differences in immunocompetence reflect resistance of sticklebacks against the eye fluke diplostomum pseudospathaceum.we investigated population differences in immunological adaptation of three-spined sticklebacks (gasterosteus aculeatus) to one of their most abundant macroparasites, the eye fluke diplostomum pseudospathaceum. we compared infection success in lab-bred fish of 2 populations in northern germany, from a lake, where eye flukes are prevalent, and a river, where these parasites do not occur. in order to discriminate between protection through innate and acquired immunity, we exposed fish either only ...200616393359
differences in shell shape of naturally infected lymnaea stagnalis (l.) individuals as the effect of the activity of digenetic trematode larvae.the shells of lymnaea stagnalis show great morphological variability. this phenomenon has been described as the result of an environmental influence. the main object of the present study was to compare some biometric data from shells of naturally infected and uninfected snails from 25 different lakes in the central part of poland. the height of the shell, the height of the spiral, and the width of the shell were measured. some inter- and intrapopulation differences among individuals were found. ...200516419747
an ultrastructural study of alimentary tract development in the cercariae of diplostomum pseudospathaceum (digenea: diplostomidae).morphogenesis of the alimentary canal in developing diplostomum pseudospathaceum cercariae has been studied using electron microscopy. the foregut primordium appears in early cercariae as a cellular cord. later, the lumen develops within the foregut primordium, and its cells give rise to the cellular epithelium, limiting this lumen. during subsequent development, the lateral plasma membranes, separating the cells, disappear from the primary foregut epithelium as do nuclei and most of cellular or ...200616568332
larval trematodes in freshwater molluscs from the elbe to danube rivers (southeast germany): before and today.studies on life cycles of trematodes have a long tradition in germany; (odening 1978) listed a total of 177 trematodes, which can potentially complete their life cycles in german inland waters. however, almost no recent data on the occurrence of larval stages in molluscs are available. therefore, a survey of trematodes in southeast germany was carried out in 2004. a total of 31 species of ten families (29 species of cercariae, seven species of metacercariae, and five species found of both) were ...200616670883
qualitative and quantitative behavioral traits in a community of furcocercariae trematodes: tools for species separation?many trematode cercariae show distinct behavioral features, which have commonly been used in species identification in combination with morphological characteristics. however, information regarding cercariae behavior has often not been quantified in detail, or it is scattered in the literature, which is why the appropriate level of precision in behavioral identity, particularly in groups of cercariae species showing considerable morphological overlap, has not been properly established. in this s ...200718314675
digenea species in chosen populations of freshwater snails in northern and central part of poland.background: the aim of this work was to determine the biodiversity of digenean larvae in the snail populations from various water bodies. material and methods: snails under study were collected from 29 reservoirs situated in northern and central part of poland. during the period 1999-2005 10.581 snails from 6 species (among which two species dominated: lymnaea stagnalis--9.469, and planorbarius corneus--737 specimens) were examined for shedding cercariae. the total number of 4.404 molluscs was p ...200718441876
diversity and specificity in diplostomum spp. metacercariae in freshwater fishes revealed by cytochrome c oxidase i and internal transcribed spacer this study, sequences from the barcode region of cytochrome c oxidase i (coi) were used to distinguish diplostomum spp. in a sample of 497 metacercariae collected from diverse fishes of the st. lawrence river, canada and findings were corroborated with internal transcribed spacer (its) regions of rdna. twelve species were detected based on sequences and metacercarial specificity for hosts and tissues. although this is an unusually high diversity, additional species are likely to exist in the ...201019737570
is the population genetic structure of complex life cycle parasites determined by the geographic range of the most motile host?due to their particular way of life, dispersal of parasites is often mediated by their host's biology. dispersal distance is relevant for parasites because high degree of dispersal leads to high gene flow, which counters the rate of parasite local adaptation in the host populations. parasites with complex life cycles need to exploit sequentially more than one host species to complete their life cycle. most trematode parasites have such complex life cycles involving invertebrate and vertebrate ho ...201020804859
morphology, ultrastructure, genetics, and morphometrics of diplostomum sp. (digenea: diplostomidae) metacercariae infecting the european flounder, platichthys flesus (l.) (teleostei: pleuronectidae), off the northwest coast of portugal.the morphology, ultrastructure, genetics, and morphometrics of a species of diplostomum von nordmann 1832 (digenea: diplostomidae), isolated from the european flounder (platichthys flesus (l.)) caught off the northwest coast of portugal, are characterized. the metacercarial stage was found unencysted in the lens capsule of the eye. light microscopical observations revealed the existence of some variability in specimen shape and size, with two morphotypes, referred to as "round" and "long", being ...201121626424
synchronous attack is advantageous: mixed genotype infections lead to higher infection success in trematode parasite genotypes typically compete for host resources limiting their fitness. the intensity of such competition depends on whether parasites are reproducing in a host, or using it primarily as a transmission vehicle while not multiplying in host tissues (referred to as 'competition hypothesis'). alternatively, simultaneous attack and co-infection by several parasite genotypes might facilitate parasite infection because such a diverse attack could present an additional challenge to ...201121632629
the neuromuscular system in freshwater furcocercaria from belarus. ii diplostomidae, strigeidae, and cyathocotylidae.the neuromuscular system (nms) in cercariae of diplostomum pseudospathaceum, cotylurus szidati, australapatemon burti, holostephanus volgensis, and paracoenogonimus ovatus was studied with immunocytochemical methods and confocal scanning laser microscopy. the patterns of f-actin in the musculature, 5-ht immunoreactive (-ir), fmrf-amide-ir neuronal elements, and a-tubulin-ir in sensory receptors were investigated. the nms in the five species studied were compared with each other and with three sp ...201121748349
are sick individuals weak competitors? competitive ability of snails parasitized by a gigantism-inducing trematode.parasitized individuals are often expected to be poor competitors because they are weakened by infections. many trematode species, however, although extensively exploiting their mollusc hosts, also induce gigantism (increased host size) by diverting host resources towards growth instead of reproduction. in such systems, alternatively to reduced competitive ability due to negative effects of parasitism on host performance, larger size could allow more efficient resource acquisition and thus incre ...201324205383
vertebrate defense against parasites: interactions between avoidance, resistance, and tolerance.hosts can utilize different types of defense against the effects of parasitism, including avoidance, resistance, and tolerance. typically, there is tremendous heterogeneity among hosts in these defense mechanisms that may be rooted in the costs associated with defense and lead to trade-offs with other life-history traits. trade-offs may also exist between the defense mechanisms, but the relationships between avoidance, resistance, and tolerance have rarely been studied. here, we assessed these t ...201728116053
learned parasite avoidance is driven by host personality and resistance to infection in a fish-trematode interaction.cognitive abilities related to the assessment of risk improve survival. while earlier studies have examined the ability of animals to learn to avoid predators, learned parasite avoidance has received little interest. in a series of behavioural trials with the trematode parasite diplostomum pseudospathaceum, we asked whether sea trout (salmo trutta trutta) hosts show associative learning in the context of parasitism and if so, whether learning capacity is related to the likelihood of infection me ...201627605504
comparative transcriptomics of stickleback immune gene responses upon infection by two helminth parasites, diplostomum pseudospathaceum and schistocephalus solidus.immune systems of vertebrates are much more diverse than previously thought, in particular at the base of the vertebrate clade. rna-seq was used to describe in detail the transcriptomic response of stickleback hosts to infection by two helminth parasites, the trematode diplostomum pseudospathaceum (2 genotypes plus a genotype mix) and the cestode schistocephalus solidus. based on a global transcription profiling, we present immune genes that are active during chronic or multiple repeated infecti ...201627373340
effects of environmental variation on host-parasite interaction in three-spined sticklebacks (gasterosteus aculeatus).recent research provides accumulating evidence that the evolutionary dynamics of host-parasite adaptations strongly depend on environmental variation. in this context, the three-spined stickleback (gasterosteus aculeatus) has become an important research model since it is distributed all over the northern hemisphere and lives in very different habitat types, ranging from marine to freshwater, were it is exposed to a huge diversity of parasites. while a majority of studies start from explorations ...201627289265
interactions among bacterial strains and fluke genotypes shape virulence of co-infection.most studies of virulence of infection focus on pairwise host-parasite interactions. however, hosts are almost universally co-infected by several parasite strains and/or genotypes of the same or different species. while theory predicts that co-infection favours more virulent parasite genotypes through intensified competition for host resources, knowledge of the effects of genotype by genotype (g × g) interactions between unrelated parasite species on virulence of co-infection is limited. here, w ...201526674949
host infection history modifies co-infection success of multiple parasite by multiple parasite genotypes are common and have important implications for host-parasite ecology and evolution through within-host interactions. typically, these infections take place sequentially, and therefore, the outcome of co-infection may be shaped by host immune responses triggered by previous infections. for example, in vertebrates, specific immune responses play a central role in protection against disease over the course of life, but co-infection research has mostly fo ...201626589834
immunity comes first: the effect of parasite genotypes on adaptive immunity and immunization in three-spined sticklebacks.adaptive immunity in vertebrates can confer increased resistance against invading pathogens upon re-infection. but how specific parasite genotypes affect the temporal transition from innate to adaptive immunity under continual exposure to parasites is poorly understood. here, we investigated the effects of homologous and heterologous exposures of genetically distinct parasite lineages of the eye fluke diplostomum pseudospathaceum on gene expression patterns of adaptive immunity in sticklebacks ( ...201626400836
relative reproductive success of co-infecting parasite genotypes under intensified within-host nature, host individuals are commonly simultaneously infected with more than one genotype of the same parasite species. these co-infecting parasites often interact, which can affect their fitness and shape host-parasite ecology and evolution. many of such interactions take place through competition for limited host resources. therefore, variation in ecological factors modifying the host resource level could be important in determining the intensity of competition and the outcome of co-infecti ...201526296607
muscle architecture during the course of development of diplostomum pseudospathaceum niewiadomska, 1984 (trematoda, diplostomidae) from cercariae to metacercariae.recent confocal microscopy studies have greatly expanded our knowledge of muscle systems in cercariae and adult digeneans, but the gross anatomy and development of metacercarial musculature remain relatively little known. to further our understanding of metacercarial development, this study used phalloidin staining and confocal microscopy to examine changes in muscle architecture over the course of development from cercariae to infective metacercariae in diplostomum pseudospathaceum niewiadomska ...201625997697
specific gene expression responses to parasite genotypes reveal redundancy of innate immunity in vertebrates.vertebrate innate immunity is the first line of defense against an invading pathogen and has long been assumed to be largely unspecific with respect to parasite/pathogen species. however, recent phenotypic evidence suggests that immunogenetic variation, i.e. allelic variability in genes associated with the immune system, results in host-parasite genotype-by-genotype interactions and thus specific innate immune responses. immunogenetic variation is common in all vertebrate taxa and this reflects ...201425254967
increased ventilation by fish leads to a higher risk of are common intermediate hosts of trematode cercariae and their gills can potentially serve as important sites of penetration by these larval stages. we experimentally tested the hypothesis that volume of ventilation flow across the gills contributes to acquisition of these parasites by fish. we manipulated the intensity of ventilation by using different oxygen concentrations.201424954703
experimental evidence for parasite-induced over-winter mortality in juvenile rhodeus this study, the effects of the eye fluke diplostomum pseudospathaceum (trematoda) infection on over-winter survival of young-of-the-year (yoy) european bitterling rhodeus amarus (cyprinidae) were examined between september 2010 and april 2011. the fish were reared in semi-natural conditions to ensure that results were not confounded by other parasite infections. the cumulative mortality of r. amarus from november until april was significantly higher in d. pseudospathaceum-infected fish (57·3% ...201424773537
differences in susceptibility and immune responses of three-spined sticklebacks (gasterosteus aculeatus) from lake and river ecotypes to sequential infections with the eye fluke diplostomum pseudospathaceum.the eye fluke diplostomum pseudospathaceum is a frequent parasite of many fresh-water fish species, among those three-spined sticklebacks, particularly in lakes with lymnaeid snails, its first intermediate hosts. cercariae released from host-snails, penetrate the skin of their fish hosts and within 24 h migrate to the immunologically inert eye lenses. thus, individual d. pseudospathaceum are exposed to the fish immune system only for a short time, suggesting that only innate immunity can be acti ...201424656136
grouping facilitates avoidance of parasites by fish.parasite distribution is often highly heterogeneous, and intensity of infection depends, among other things, on how well hosts can avoid areas with a high concentration of parasites. we studied the role of fish behaviour in avoiding microhabitats with a high infection risk using oncorhynchus mykiss and cercariae of diplostomum pseudospathaceum as a model. spatial distribution of parasites in experimental tanks was highly heterogeneous. we hypothesized that fish in groups are better at recognizin ...201324499549
[parasites of the osprey (pandion haliaetus) in northwestern russia].new data on ospey parasites in karelian republic are given. one specimen was investigated. two parasite species--nematostrigea serpens and diplostomum pseudospathaceum were found. trematoda d. pseudospathaceum was recorded in osprey parasite fauna for the first time.201424455873
in vitro leukocyte response of three-spined sticklebacks (gasterosteus aculeatus) to helminth parasite antigens.helminth parasites of teleost fish have evolved strategies to evade and manipulate the immune responses of their hosts. responsiveness of fish host immunity to helminth antigens may therefore vary depending on the degree of host-parasite counter-adaptation. generalist parasites, infective for a number of host species, might be unable to adapt optimally to the immune system of a certain host species, while specialist parasites might display high levels of adaptation to a particular host species. ...201424176687
genotype-specific vs. cross-reactive host immunity against a macroparasite.vertebrate hosts often defend themselves against several co-infecting parasite genotypes simultaneously. this has important implications for the ecological dynamics and the evolution of host defence systems and parasite strategies. for example, it can drive the specificity of the adaptive immune system towards high genotype-specificity or cross-reactivity against several parasite genotypes depending on the sequence and probability of re-infections. however, to date, there is very little evidence ...201324167622
genotypic and phenotypic variation in transmission traits of a complex life cycle parasite.characterizing genetic variation in parasite transmission traits and its contribution to parasite vigor is essential for understanding the evolution of parasite life-history traits. we measured genetic variation in output, activity, survival, and infection success of clonal transmission stages (cercaria larvae) of a complex life cycle parasite (diplostomum pseudospathaceum). we further tested if variation in host nutritional stage had an effect on these traits by keeping hosts on limited or ad l ...201323919156
occurrence of diplostomum pseudospathaceum niewiadomska, 1984 and d. mergi dubois, 1932 (digenea: diplostomidae) in danish freshwater snails: ecological and molecular data.freshwater pulmonate snails from three locations in lake furesø north of copenhagen were screened for infection with furcocercariae (by shedding in the laboratory) and recovered parasite larvae were diagnosed by molecular methods (by performing pcr of rdna and sequencing the internal transcribed spacer [its] region). overall prevalence of infection in snails was 2%. recovered cercariae from lymnaea stagnalis (linnaeus) were diagnosed as diplostomum pseudospathaceum niewiadomska, 1984 (prevalence ...201323724738
genetic compatibilities, outcrossing rates and fitness consequences across life stages of the trematode diplostomum pseudospathaceum.many parasitic helminths exhibit mixed mating systems, and switches between self-fertilization and outcrossing may be influenced by environmental conditions and parasite demography. while inbreeding depression selects against the development of purely self-fertilizing populations, genetic compatibility may contribute to stabilizing mixed strategies. here we study the effects of inbreeding and genetic compatibility on offspring fitness in the digenean trematode diplostomum pseudospathaceum, a par ...201323416153
molecular prospecting for european diplostomum (digenea: diplostomidae) reveals cryptic diversity.we believe this study is the first attempt to address molecular prospecting for species diversity of diplostomum (digenea: diplostomidae) in europe. a database linking sequences from the barcode region of the cytochrome c oxidase subunit 1 (cox1) mitochondrial gene and from the internal transcribed spacer cluster (its1-5.8s-its2) of the rrna gene was generated for larval and adult parasites of snails, fish and gulls from central europe. analyses of the novel cox1 dataset revealed the presence of ...201323201234
prevalence of infection as a predictor of multiple genotype infection frequency in parasites with multiple-host life nature, parasites commonly share hosts with other conspecific parasite genotypes. while adult parasites typically show aggregated distribution in their final hosts, aggregation of clonal parasite genotypes in intermediate hosts, such as those of trematodes in molluscs, is not generally known. however, infection of a host by multiple parasite genotypes has significant implications for evolution of virulence and host-parasite coevolution. aggregated distribution of the clonal stages can increas ...201322985060
reciprocal interaction matrix reveals complex genetic and dose-dependent specificity among coinfecting parasites.understanding genetic specificity in factors determining the outcome of host-parasite interactions is especially important as it contributes to parasite epidemiology, virulence, and maintenance of genetic variation. such specificity, however, is still generally poorly understood. we examined genetic specificity in interactions among coinfecting parasites. in natural populations, individual hosts are often simultaneously infected by multiple parasite species and genotypes that interact. such inte ...201222854074
freshwater mussels (anodonta anatina) reduce transmission of a common fish trematode (eye fluke, diplostomum pseudospathaceum).recent results suggest that bivalves can play an important role in restraining the spread of various aquatic infections. however, the ability of mussels to remove free-living stages of macroparasites and reduce their transmission is still understudied, especially for freshwater ecosystems. we investigated the influence of the common freshwater mussel (anodonta anatina) on the transmission of a trematode (eye fluke, diplostomum pseudospathaceum), which frequently infects fish in farms and natural ...201728766473
positive density-dependent growth supports costs sharing hypothesis and population density sensing in a manipulative parasite.parasites manipulate their hosts' phenotype to increase their own fitness. like any evolutionary adaptation, parasitic manipulations should be costly. though it is difficult to measure costs of the manipulation directly, they can be evaluated using an indirect approach. for instance, theory suggests that as the parasite infrapopulation grows, the investment of individual parasites in host manipulation decreases, because of cost sharing. another assumption is that in environments where manipulati ...201728653588
changes in spination patterns over the course of metacercarial development of diplostomum pseudospathaceum niewiadomska, 1984 (trematoda, diplostomidae).metacercarial development of most diplostomum species including d. pseudospathaceum occurs in the eye lenses of their fish hosts and is accompanied by radical morphological changes often referred to as metamorphosis. one of the structures undergoing substantial changes in d. pseudospathacewn are tegumental spines. the present study used phalloidin staining and confocal microscopy to examine these changes in d. pseudospathaceum over the course of development from 3-day-old to infective metacercar ...201729211423
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