the envelope surrounding polymorphus minutus (goeze, 1782) (acanthocephala) during its development in the intermediate host, gammarus pulex. 196414227633
effects of two acanthocephalan parasites on the fecundity and pairing status of female gammarus pulex (crustacea: amphipoda).acanthocephalan parasites are known to alter the reproductive biology and physiology of their hosts in various ways. in this study we investigated the influence of two acanthocephalan parasites, pomphorhynchus laevis and polymorphus minutus, on the fecundity and pairing success of female gammarus pulex. the results show that p. laevis and p. minutus affect female intermediate host reproduction in different ways. females infected with p. minutus were totally castrated, whereas those infected with ...200212095239
parasitic infection and developmental stability: fluctuating asymmetry in gammarus pulex infected with two acanthocephalan species.several studies have reported a negative association between developmental stability and parasitic infection. however, the host-parasite associations examined so far consist only of a limited number of parasite taxa, and developmental stability was appraised on definitive hosts. the present study examines the association between infection by 2 acanthocephalan parasites. pomphorhynchus laevis and polymorphus minutus, and the developmental stability of their common intermediate host gammarus pulex ...200212053979
conflict between co-occurring manipulative parasites? an experimental study of the joint influence of two acanthocephalan parasites on the behaviour of gammarus pulex.when two parasite species are manipulators and have different definitive hosts, there is a potential for conflict between them. selection may then exist for either avoiding hosts infected with conflicting parasites, or for hijacking, i.e. competitive processes to gain control of the intermediate host. the evidence for both phenomena depends largely on the study of the relative competitive abilities of parasites within their common intermediate host. we studied the effects of simultaneous infecti ...200010874725
the development of the body wall of polymorphus minutus (acanthocephala) in its intermediate host gammarus pulex. 19695770075
the effect of the acanthocephalan pomphorhynchus laevis upon the respiration of its intermediate host, gammarus pulex. 19744826717
carotenoids of two freshwater amphipod species (gammarus pulex and g. roeseli) and their common acanthocephalan parasite polymorphus minutus.carotenoid compositions of two freshwater gammarus species (crustacea: amphipoda) and of their common acanthocephalan parasite polymorphus minutus were characterized. the effect of carotenoid uptake by the parasite was addressed by comparing the carotenoid content of uninfected and infected female hosts. using high-pressure liquid chromatography (hplc), co-chromatography of reference pigments and electron ionization mass spectrometry of collected hplc fractions (ei-ms), several xanthophylls and ...200415364296
[total chlorine and water content of gammarus pulex pulex (l.) and echinogammarus berilloni (c.) living in fresh water and diluted sea water]. 196414186954
biomarkers as diagnostic tools for evaluating effects of unknown past water quality conditions on stream organisms.the following biomarkers were investigated in stream populations of juvenile brown trout (salmo trutta f. fario) and gammarids (gammarus pulex) to determine if crayfish mortality could have been confounded by pollutants: (1) alterations of fish liver ultrastructure, (2) fish gill and kidney histopathology, (3) stress protein (hsp70) expression in fish liver and gills and in gammarids, and (4) changes in various blood parameters of brown trout. in addition, the following measurements were conduct ...200212521141
[comparative study of the toxicity of metal chlorides and a synthetic organic molluscacide, n-tritylmorpholine, in 2 fresh-water amphipods, gammarus pulex and echinogammarus berilloni].the effects of three metal salts (bacl2, cucl2, zncl2) and of n-trityl-morpholine (triphenmorph) were studied on two aquatic amphipod species, gammarus pulex and echinogammarus berilloni. experiments were made up in eucalcic and oligocalcic waters for determining the lc50 at different exposure times. the order of toxicity was the same in eucalcic water with the two species: triphenmorph greater than cu2+ greater than zn2+ greater than ba2+. this order was the same in oligocalcic water with echin ...19863827145
toxicity of four common pollutants to the freshwater macroinvertebrates chironomus riparius meigen (insecta:diptera) and gammarus pulex (l.) (crustacea: amphipoda).the lethal toxicities of the four pollutants 3,4-dichloroaniline (dca), atrazine, copper, and lindane were determined for the 2nd larval instar of the insect chironomus riparius meigen and the juvenile stage (2nd or 3rd moult) of the crustacean gammarus pulex (l.). median lethal concentrations (lc50s) were determined over a 240 h test period. the order of toxicity of the test chemicals is different for each species. for c. riparius, lindane was the most toxic, followed by copper, dca, and atrazi ...19911719943
effects of 3,4-dichloroaniline on the growth of two freshwater macroinvertebrates in a stream mesocosm.the growth of the freshwater macroinvertebrates gammarus pulex (l.) and chironomus riparius meigen exposed to 3,4-dichloroaniline in chambers within stream mesocosms was determined. dca significantly affected the growth of neonate g. pulex and third instar c. riparius over 25 and 12 days, respectively. the no-observed-effect concentrations (noecs) obtained in the tests were 0.08 mg dca liter-1 (g. pulex) and 0.76 mg dca liter-1 (c. riparius) and these are compared to toxicity data from other inv ...19947529166
infection with an acanthocephalan manipulates an amphipod's reaction to a fish predator's odours.many parasites with complex life cycles increase the chances of reaching a final host by adapting strategies to manipulate their intermediate host's appearance, condition or behaviour. the acanthocephalan parasite pomphorhynchus laevis uses freshwater amphipods as intermediate hosts before reaching sexual maturity in predatory fish. we performed a series of choice experiments with infected and uninfected gammarus pulex in order to distinguish between the effects of visual and olfactory predator ...200717049528
[protein hydrolysates, obtained from crustaceans by an electrochemical method, as a basis for microbiological culture media].the utility of protein hydrolysates extracted electrochemically from crustaceans (gammarus pulex and shrimp) as major components of microbiological nutrient media was demonstrated. saprophytic soil bacteria of the genera bacillus and pseudomonas and the family enterobactericeae displayed a good growth and typical morphology of their colonies on the experimental media in question.200314520973
a predator's dilemma: prey choice and parasite susceptibility in three-spined sticklebacks.the acanthocephalan parasite pomphorhynchus laevis is transmitted by a suitable intermediate host such as the amphipod gammarus pulex to its definitive fish host. parasite-induced alterations in both appearance and behaviour concur to render infected gammarids more vulnerable to predation, thus promoting parasite transmission. experimental infection of laboratory bred full- and half-sib groups of three-spined sticklebacks (gasterosteus aculeatus) provided evidence that the parasite imposes a sur ...200312741513
identification of endocrine-disrupting effects in aquatic vertebrates and invertebrates: report from the european idea project.the eu-funded project idea aimed to evaluate (a) what parameters and endpoints allow the detection of endocrine-mediated developmental and reproductive effects of (xeno)estrogens in life cycle- and life stage-specific toxicity tests with the zebrafish danio rerio, a small laboratory fish used in many ecotoxicity test guidelines, and (b) whether substances that act as estrogens in vertebrates may also adversely affect the development, differentiation, and reproduction of aquatic invertebrates. th ...200312651186
overview and quantification of the factors affecting the upstream and downstream movements of gammarus pulex (amphipoda).human activities have severely deteriorated the flemish river systems, and many functions such as drinking water supply, fishing, ... are threatened. because their restoration entails drastic social (e.g. change in habits with regard to water use and discharge, urban planning) and economical (e.g. investment in nature restoration, wastewater treatment system installation) consequences, the decisions should be taken with enough forethought. ecosystem models can act as interesting tools to support ...200314696234
patterns of intermediate host use and levels of association between two conflicting manipulative parasites.for many parasites with complex life cycles, manipulation of intermediate host phenotypes is often regarded as an adaptation to increase the probability of successful transmission. this phenomenon creates opportunities for either synergistic or conflicting interests between different parasite species sharing the same intermediate host. when more than one manipulative parasite infect the same intermediate host, but differ in their definitive host, selection should favour the establishment of a ne ...200211796118
differential influence of pomphorhynchus laevis (acanthocephala) on the behaviour of native and invader gammarid species.although various species of acanthocephalan parasites can increase the vulnerability of their amphipod intermediate hosts to predation, particularly by altering their photophobic behaviour, their influence on the structure of amphipod communities and the success of invader species has so far received little attention. we compared the prevalence and behavioural influence of a fish acanthocephalan parasite, pomphorhynchus laevis, in two species of amphipods, gammarus pulex and gammarus roeseli in ...200011428335
the effect of the acanthocephalan parasite pomphorhynchus laevis on the lipid and glycogen content of its intermediate host gammarus pulex.besides conspicuous changes in behaviour, manipulative parasites may also induce subtle physiological effects in the host that may also be favourable to the parasite. in particular, parasites may be able to influence the re-allocation of resources in their own favour. we studied the association between the presence of the acanthocephalan parasite, pomphorhynchus laevis, and inter-individual variation in the lipid and glycogen content of its crustacean host, gammarus pulex (amphipoda). infected g ...200111306112
larval morphology, genetic divergence, and contrasting levels of host manipulation between forms of pomphorhynchus laevis (acanthocephala).studies on parasite species with a wide geographic and ecological range may be confounded by still equivocal taxonomic identification. here, we investigated genetic polymorphism and behavioural changes induced in a common intermediate host, in two different forms of pomphorhynchus laevis based on the morphology of the larval infective stage (cystacanth). a 'smooth type' (s) and a 'wrinkled type' (w) of cystacanth were distinguished based on their surface and shape. we analysed sequence divergenc ...200414711589
the role of ion regulation in the control of the distribution of gammarus tigrinus (sexton) in salt-polluted rivers.fluctuating salinities at different sites on the german salt-polluted rivers werra and weser were compared with extracellular ion levels of specimens of gammarus tigrinus (sexton; amphipoda, crustacea), collected at the same sites. g. tigrinus regulated haemolymph concentrations of inorganic anions (cl-, so(4)2-, po(4)3-) and cations (na+, k+, mg2+, ca2+) during fluctuations of salt pollution in the upper weser. this capacity to regulate varying levels of salt pollution in the upper weser, corre ...200010707328
development of methods for evaluating toxicity to freshwater ecosystems.this article presents a summary of a collaborative research program involving five european research groups, that was partly funded by the european commission under its environmental research program. the objective of the program was to develop aquatic toxicity tests that could be used to obtain data for inclusion at level 2 of the risk evaluation scheme for the notification of substances as required by the 7th amendment to ec directive 79/831/eec. currently only a very limited number of test me ...200010648133
ttagg telomeric repeats in chromosomes of some insects and other arthropods.we studied the occurrence of the ttagg telomere repeats by fluorescence in-situ hybridization (fish) and southern hybridization in ten insect species and two other arthropods. (ttagg)n-containing telomeres were found in three lepidoptera species, the silkworm bombyx mori (in which the telomeric sequence was recently discovered), the flour moth ephestia kuehniella, and the wax moth galleria mellonella, in one species of hymenoptera, the honey bee apis mellifera, in one species of coleoptera, the ...199910560968
uptake of lead by pomphorhynchus laevis cystacanths in gammarus pulex and immature worms in chub (leuciscus cephalus).the uptake of lead by cystacanths of the acanthocephalan pomphorhynchus laevis in naturally infected amphipods, gammarus pulex, and by immature parasites in experimentally infected fish, leuciscus cephalus, was examined following 3-week experimental exposures (0.01 and 0.1 mg l(-1) pb2+). both g. pulex and the cystacanths of p. laevis accumulated lead but concentrations in the parasites were lower than in the host tissues at the low lead dose and significantly lower at the high dose. p. laevis f ...19989694375
colonization and establishment of pomphorhynchus laevis (acanthocephala) in an isolated english river.the successful colonization, establishment and spread of pomphorhynchus laevis in a small, isolated, devon river 128 km from the parasite's nearest focus in dorset was followed over 11 years from 1985. the parasite was first detected in anguilla anguilla and platichthys flesus in 1988: by 1995 it had attained prevalence levels of 22.6% in a. anguilla and 43.6% in p. flesus and also occurred in 100% salmo trutta, 50% cottus gobio and noemacheilus barbatulus. as judged by prevalence, abundance, pr ...19968991914
a stream mesocosm study on the ecological effects of a c12-15 linear alcohol ethoxylate surfactant.the responses of fish, invertebrates, and periphyton during a 56-day exposure to a c(12-15) linear alcohol ethoxylate surfactant were studied in stream mesocosms. an individual stream consisted of a slow-flowing pool section and a faster-flowing riffle section. the surfactant has an average distribution of nine ethoxylate groups per mole of alcohol. eight stream mesocosms were used to test the effects of seven concentrations of the surfactant. time-averaged, mean, measured concentrations were 20 ...200415157571
ecological impacts of the microsporidian parasite pleistophora mulleri on its freshwater amphipod host gammarus duebeni celticus.the microsporidian parasite, pleistophora mulleri, infects the abdominal muscle of the freshwater amphipod gammarus duebeni celticus. we recently showed that p. mulleri infection was associated with g. d. celticus hosts being more vulnerable to predation by the invasive amphipod gammarus pulex. parasitized g. d. celticus also had a reduced ability to prey upon other co-occurring amphipods. we suggested the parasite may have pervasive influences on host ecology and behaviour. here, we examine the ...200516178354
[temperature and shell calcium recovery following moult in echinogammarus berilloni. comparative study with gammarus pulex pulex]. 19724651600
[the life cycle of microphallus gracilis baer, 1943, a parasite of neomys fodiens in the pyrenees. modalities of the transmission of the digenea in nature (author's transl)].microphallus gracilis develops to the sporocyst stage in the digestive gland of the snail bythinella reyniesii. the xiphidio-cercaria monostomous, anenterous in type, is liberated in water and actively penetrates a crustacea gammarus pulex where it encysts. from the point of view of the transmission ecology, the natural focuses of m. gracilis are composed of two different areas: an area where the parasite multiplies coinciding with biotope bythinella and an area limited to the length of the rive ...1977931318
[the life cycl of maritrema pyrenaica deblock et combes, 1965, a parasite of insectivorous micromammals in the pyrences (author's transl)].the life cycle of maritrema pyrenaica is described. m. pyrenaica develops to the sporocyst stage in the snail bythinella reyniesii. the xiphidio-cercaria, monostomous, anenterous in type, is liberated in water and actively penetrates a crustacea gammarus pulex where it encysts. from the point of view of epidemiology, the focuses of m. pyrenaica are divided into two different areas: the area where the parasites multiply (that we call "l'endemiotope") coinciding with the bythinella biotope and the ...1979533111
application of artificial neural network models to analyse the relationships between gammarus pulex l. (crustacea, amphipoda) and river characteristics.this study aimed at analysing the relationship between river characteristics and abundance of gammarus pulex. to this end, four methods which can identify the relative contribution and/or the contribution profile of the input variables in neural networks describing the habitat preferences of this species were compared: (i) the "pad" ("partial derivatives") method consists of a calculation of the partial derivatives of the output in relation to the input variables; (ii) the "weights" method is a ...200516311829
chronic toxicity of copper to five benthic invertebrates in laboratory-formulated sediment: sensitivity comparison and preliminary risk assessment.five benthic organisms commonly used for sediment toxicity testing were chronically (28 to 35 days) exposed to copper in standard laboratory-formulated sediment (following organization for economic cooperation and development guidelines) and lethal and sub-lethal toxicities were evaluated. sub-lethal endpoints considered were reproduction and biomass production for lumbriculus variegatus, growth and reproduction for tubifex tubifex, growth and emergence for chironomus riparius, and growth for ga ...200717631947
occurrence of platinum and additional traffic related heavy metals in sediments and biota.non-point sources play an important role in metal emissions into surface waters. one of the most important non-point sources is automobile traffic. recent studies determining traffic related heavy metals in surface waters have concentrated mainly on worst case scenarios by analyzing heavy metal loads in waters and sediments close to storm-water overflow inlets. the present study aims at identifying traffic related heavy metals in moderately polluted sites, as they occur in highly urbanized regio ...200716996105
some biochemical properties of delta-aminolevulinic acid dehydratase in gammarus pulex.the determination of delta-aminolevulinic acid dehydratase (alad; porphobilinogen synthetase, ec activity in aquatic organisms might be a useful marker for the identification of lead exposure. alads from the variety of different sources have been grouped into two classes based on some biochemical properties such as molecular weight, ph optimum, metal requirement and susceptibility to edta. the first group includes the enzymes from mammals and birds, while the second group alads are der ...200817904721
differential phenoloxidase activity between native and invasive gammarids infected by local acanthocephalans: differential immunosuppression?manipulative endoparasites can alter the behaviour and the physiology of their intermediate hosts in ways that increase the probability of successful transmission to the final host. this requires that the parasite is able to circumvent its host's immune defence. successful immune evasion may depend on host-parasite coevolutionary history and the appearance of new hosts invading the local host population may promote local parasite maladaptation. to test this hypothesis, we examined the effect of ...200314700193
field evidence of host size-dependent parasitism in two manipulative parasites.the distribution of parasites within host natural populations has often been found to be host age-dependent. host mortality induced by parasites is the commonest hypothesis proposed for explaining this pattern. despite its potential importance in ecology, the parasitism intensity in relation with the host age has rarely been studied in the field. the 2 manipulative acanthocephalans, polymorphus minutus and pomphorhynchus laevis, use the amphipod gammarus pulex as an intermediate host, and their ...200717918352
modification of hosts' behavior by a parasite: field evidence for adaptive manipulation.parasites relying on trophic transmission to complete their life cycles often induce modifications of their host's behavior in ways that may increase their susceptibility to predation by final hosts. these modifications have often been interpreted as parasite adaptations, but very few studies have demonstrated that host manipulation has fitness benefits for the parasite. the aim of the present study was to address the adaptive significance of parasite manipulation by coupling observations of beh ...200718051653
the effects of parasite age and intensity on variability in acanthocephalan-induced behavioural manipulation.numerous parasites with complex life cycles are able to manipulate the behaviour of their intermediate host in a way that increases their trophic transmission to the definitive host. pomphorhynchus laevis, an acanthocephalan parasite, is known to reverse the phototactic behaviour of its amphipod intermediate host, gammarus pulex, leading to an increased predation by fish hosts. however, levels of behavioural manipulation exhibited by naturally-infected gammarids are extremely variable, with some ...200818314127
acute and delayed effects of the neonicotinoid insecticide thiacloprid on seven freshwater arthropods.ecotoxicological risk assessment of contaminants often is based on toxicity tests with continuous-exposure profiles. however, input of many contaminants (e.g., insecticides) to surface waters typically occurs in pulses rather than continuously. neonicotinoids are a new group of insecticides, and little is known about their toxicity to nontarget freshwater organisms and potential effects on freshwater ecosystems. the aim of the present research was to assess effects of short-term (24-h) exposure ...200818348641
variation in the bioaccumulation of a sediment-sorbed hydrophobic compound by benthic macroinvertebrates: patterns and mechanisms.aquatic ecological risk assessment is primarily focused on aqueous exposure, but many hydrophobic contaminants bind to particulate material and accumulate in sediments. the risk posed by such contaminants is partially dependent on the importance of dietary exposure. here, we describe the bioaccumulation of a highly hydrophobic compound (dioctadecyl-dimethyl ammonium chloride (dodmac)) to four freshwater macroinvertebrates (i.e., asellus aquaticus, chironomus riparius, gammarus pulex, lumbriculus ...200717396674
do distantly related parasites rely on the same proximate factors to alter the behaviour of their hosts?phylogenetically unrelated parasites often increase the chances of their transmission by inducing similar phenotypic changes in their hosts. however, it is not known whether these convergent strategies rely on the same biochemical precursors. in this paper, we explored such aspects by studying two gammarid species (gammarus insensibilis and gammarus pulex; crustacea: amphipoda: gammaridae) serving as intermediate hosts in the life cycle of two distantly related parasites: the trematode, micropha ...200617015311
altered host behaviour and brain serotonergic activity caused by acanthocephalans: evidence for specificity.manipulative parasites can alter the phenotype of intermediate hosts in various ways. however, it is unclear whether such changes are just by-products of infection or adaptive and enhance transmission to the final host. here, we show that the alteration of serotonergic activity is functionally linked to the alteration of specific behaviour in the amphipod gammarus pulex infected with acanthocephalan parasites. pomphorhynchus laevis and, to a lesser extent, pomphorhynchus tereticollis altered pho ...200617015346
differential influence of pomphorhynchus laevis (acanthocephala) on brain serotonergic activity in two congeneric host species.the physiological mechanisms by which parasites with complex life cycles manipulate the behaviour of their intermediate hosts are still poorly understood. in burgundy, eastern france, the acanthocephalan parasite pomphorhynchus laevis inverses reaction to light in its amphipod host gammarus pulex, but not in gammarus roeseli, a recent invasive species. here, we show that this difference in manipulation actually reflects a difference in the ability of the parasite to alter brain serotonergic (5-h ...200717443968
interspecific differences in carotenoid content and sensitivity to uvb radiation in three acanthocephalan parasites exploiting a common intermediate host.few endoparasite species are pigmented. acanthocephalans are an exception however, with several species being characterised by yellow to orange colouration both at the immature (cystacanth) and adult stages. however, the functional and adaptive significance of carotenoid-based colourations in acanthocephalans remains unclear. one possibility is that the carotenoid content of acanthocephalan cystacanths acts as a protective device against ultra-violet radiation (uvr) passing through the transluce ...201120833172
behavioural and physiological effects of the trophically transmitted cestode parasite, cyathocephalus truncatus, on its intermediate host, gammarus pulex.some parasites with complex life-cycles are able to manipulate the behaviour of their intermediate hosts in a way that increases their transmission to the next host. gammarids infected by the tapeworm cyathocephalus truncatus (cestoda: spathebothriidea) are known to be more predated by fish than uninfected ones, but potential behavioural manipulation by the parasite has never been investigated. in this study, we tested the hypothesis that c. truncatus is able to manipulate the behaviour of one o ...200717640401
intraspecific conflict over host manipulation between different larval stages of an acanthocephalan parasite.competitive interactions between coinfecting parasites are expected to be strong when they affect transmission success. when transmission is enhanced by altering host behaviour, intraspecific conflict can lead to 'coinfection exclusion' by the first-in parasite or to a 'sabotage' of behavioural manipulation by the youngest noninfective parasite. we tested these hypotheses in the acanthocephalan parasite pomphorhynchus laevis, reversing phototaxis in its intermediate host gammarus pulex. no evide ...201020964763
parasitic infection manipulates sodium regulation in the freshwater amphipod gammarus pulex (l.).the acanthocephalan parasite polymorphus minutus induces both physiological and behavioural effects in its intermediate host, gammarus pulex. the net effect of parasite infection is to increase the likelihood of transmission to the definitive host. osmoregulation is an energetically expensive mechanism that allows g. pulex to survive in dilute media. any factor influencing osmoregulation is thus likely to affect the allocation of resources to other areas. this study investigated whether p. minut ...201121440657
are cryptic host species also cryptic to parasites? host specificity and geographical distribution of acanthocephalan parasites infecting freshwater gammarus.many parasites infect multiple host species. in coevolving host-parasite interactions, theory predicts that parasites should be adapted to locally common hosts, which could lead to regional shifts in host preferences. we studied the interaction between freshwater gammarus (crustacea, amphipoda) and their acanthocephalan parasites using a large-scale field survey and experiments, combined with molecular identification of cryptic host and parasite species. gammarus pulex is a common host for multi ...201121470578
pairing success and sperm reserve of male gammarus pulex infected by cyathocephalus truncatus (cestoda: spathebothriidea).summarymanipulative parasites with complex life cycles are known to induce behavioural and physiological changes in their intermediate hosts. cyathocephalus truncatus is a manipulative parasite which infects gammarus pulex as intermediate host. g. pulex males display pre-copulatory mate guarding as a response to male-male competition for access to receptive females. in this paper, we tested the influence that c. truncatus-infection might have on male g. pulex sperm number and pairing success. we ...201121810304
larval size in acanthocephalan parasites: influence of intraspecific competition and effects on intermediate host behavioural changes.parasites often face a trade-off between exploitation of host resources and transmission probabilities to the next host. in helminths, larval growth, a major component of adult parasite fitness, is linked to exploitation of intermediate host resources and is influenced by the presence of co-infecting conspecifics. in manipulative parasites, larval growth strategy could also interact with their ability to alter intermediate host phenotype and influence parasite transmission.201222876882
protection first then facilitation: a manipulative parasite modulates the vulnerability to predation of its intermediate host according to its own developmental stage.many trophically transmitted parasites with complex life cycles manipulate their intermediate host behavior in ways facilitating their transmission to final host by predation. this facilitation generally results from lowering host's antipredatory defenses when the parasite is infective to the final host. however, a recent theoretical model predicts that an optimal parasitic strategy would be to protect the intermediate host from predation when noninfective, before switching to facilitation when ...201121884065
the combined effects of water level reduction and an increase in ammonia concentration on organic matter processing by key freshwater shredders in alluvial a global change context, the intensity and the frequency of drastic low flow periods or drought events will most likely increase to a substantial extent over the coming decades, leading to a modification in the abiotic characteristics of wetlands. this change in environmental parameters may induce severe shifts in plant and animal communities and the functioning of ecosystems. in this study, we experimentally estimated the effect of drought and the accumulation of ammonia (nh3 ) on the feedin ...201223504834
infection with acanthocephalans increases the vulnerability of gammarus pulex (crustacea, amphipoda) to non-host invertebrate predators.phenotypic alterations induced by parasites in their intermediate hosts often result in enhanced trophic transmission to appropriate final hosts. however, such alterations may also increase the vulnerability of intermediate hosts to predation by non-host species. we studied the influence of both infection with 3 different acanthocephalan parasites (pomphorhynchus laevis, p. tereticollis, and polymorphus minutus) and the availability of refuges on the susceptibility of the amphipod gammarus pulex ...200818371238
habitat segregation mediates predation by the benthic fish cottus gobio on the exotic amphipod species gammarus roeseli.predation is often considered as one of the most important biotic factor determining the success of exotic species. the freshwater amphipod gammarus roeseli has widely colonized western europe, where it is frequently found in sympatry with the native species (gammarus pulex). previous laboratory experiments revealed that g. roeseli may have an advantage over g. pulex through differential predation by native fish (brown trout). morphological anti-predator defences (spines) were found responsible ...200818523749
immune depression induced by acanthocephalan parasites in their intermediate crustacean host: consequences for the risk of super-infection and links with host behavioural manipulation.parasite survival in hosts mainly depends on the capacity to circumvent the host immune response. acanthocephalan infections in gammarids are linked with decreased activity of the prophenoloxidase (propo) system, suggesting an active immunosuppression process. nevertheless, experimental evidence for this hypothesis is lacking: whether these parasites affect several immune pathways is unknown and the consequences of such immune change have not been investigated. in particular, the consequences fo ...200918708062
parasite-altered behavior in a crustacean intermediate host: field and laboratory studies.the effects of the acanthocephalan parasite pomphorhynchus laevis on the behavior of its crustacean intermediate host, the amphipod echinogammarus stammeri, were studied. a drift study revealed that infected amphipods were disproportionately represented in drift samples taken throughout a 24-hr period; infection with more than 1 parasite enhanced this effect. infection also interacted with the daily timing of drift, with parasitized amphipods beginning to drift earlier in the evening. two distin ...19989920297
responses of aquatic organisms to metal pollution in a lowland river in flanders: a comparison of diatoms and macroinvertebrates.the role of macroinvertebrates and diatoms as indicator for metal pollution was investigated by assessing both biota along a metal gradient in the belgian river the dommel. macroinvertebrates and diatoms were sampled in summer and winter and physical-chemical characteristics of the water were measured at four different sample periods and related to sediment characteristics. although metal concentrations, except cadmium, in the water nowhere exceeded water quality standards, high metal concentrat ...200818778849
carotenoid-based colour of acanthocephalan cystacanths plays no role in host manipulation.manipulation by parasites is a catchy concept that has been applied to a large range of phenotypic alterations brought about by parasites in their hosts. it has, for instance, been suggested that the carotenoid-based colour of acanthocephalan cystacanths is adaptive through increasing the conspicuousness of infected intermediate hosts and, hence, their vulnerability to appropriate final hosts such as fish predators. we revisited the evidence in favour of adaptive coloration of acanthocephalan pa ...200918796399
variation and covariation in infectivity, virulence and immunodepression in the host-parasite association gammarus pulex-pomphorhynchus laevis.parasites often manipulate host immunity for their own benefit, either by exacerbating or suppressing the immune response and this may directly affect the expression of parasite virulence. however, genetic variation in immunodepression, which is a prerequisite to its evolution, and the relationship between immunodepression and virulence, have rarely been studied. here, we investigated the variation among sibships of the acanthocephalan parasite, pomphorhynchus laevis, in infecting and in immunod ...200919726474
biological invasion and parasitism: invaders do not suffer from physiological alterations of the acanthocephalan pomphorhynchus laevis.biological invasions expose parasites to new invasive hosts in addition to their local hosts. however, local parasites are often less successful in infecting and exploiting their new hosts. this may have major consequences for the competitive ability of hosts, and finally on the fate of the parasite-host community. in burgundy (eastern france), the acanthocephalan parasite, pomphorhynchus laevis, infects 2 amphipod species living in sympatry: the native gammarus pulex and the invasive gammarus r ...201019765338
parasite virulence when the infection reduces the host immune response.parasite infections often induce a reduction in host immune response either because of a direct manipulation of the immune system by the parasite or because of energy depletion. although infection-induced immunodepression can favour the establishment of the parasite within the host, a too severe immunodepression may increase the risk of infection with opportunistic pathogens, stopping the period over which the parasite can be transmitted to other hosts. here, we explore how the risk of contracti ...201020200031
variation between populations and local adaptation in acanthocephalan-induced parasite manipulation.many trophically transmitted parasites manipulate their intermediate host phenotype, resulting in higher transmission to the final host. however, it is not known if manipulation is a fixed adaptation of the parasite or a dynamic process upon which selection still acts. in particular, local adaptation has never been tested in manipulating parasites. in this study, using experimental infections between six populations of the acanthocephalan parasite pomphorhynchus laevis and its amphipod host gamm ...201020394670
microsporidian parasites feminise hosts without paramyxean co-infection: support for convergent evolution of parasitic feminisation.feminisation of amphipod crustaceans is associated with the presence of at least three microsporidian parasites and one paramyxean parasite, suggesting that the ability to feminise has evolved multiple times in parasites of amphipods. co-infection by a paramyxean with one of the putative microsporidian feminisers, dictyocoela duebenum, has inspired the alternative hypothesis that all feminisation of amphipods is caused by paramyxea and that all microsporidian associations with feminisation are d ...201525747725
co-variation between the intensity of behavioural manipulation and parasite development time in an acanthocephalan-amphipod system.pomphorhynchus laevis, a fish acanthocephalan parasite, manipulates the behaviour of its gammarid intermediate host to increase its trophic transmission to the definitive host. however, the intensity of behavioural manipulation is variable between individual gammarids and between parasite populations. to elucidate causes of this variability, we compared the level of phototaxis alteration induced by different parasite sibships from one population, using experimental infections of gammarus pulex b ...201020796137
manipulative parasites may not alter intermediate host distribution but still enhance their transmission: field evidence for increased vulnerability to definitive hosts and non-host predator avoidance.behavioural alterations induced by parasites in their intermediate hosts can spatially structure host populations, possibly resulting in enhanced trophic transmission to definitive hosts. however, such alterations may also increase intermediate host vulnerability to non-host predators. parasite-induced behavioural alterations may thus vary between parasite species and depend on each parasite definitive host species. we studied the influence of infection with 2 acanthocephalan parasites (echinorh ...201323068018
influence of host nutritional condition on post-infection traits in the association between the manipulative acanthocephalan pomphorhynchus laevis and the amphipod gammarus pulex.several parasites with complex life-cycles induce phenotypic alterations in their intermediate hosts. according to the host manipulation hypothesis, such phenotypic alterations are supposed to increase the fitness of the parasite at the expense of that of its intermediate hosts through increasing the probability of transmission to next hosts. although the phenomenon has received a large attention, the proximate factors modulating the occurrence and intensity of host manipulation remain poorly kn ...201526223476
multidimensionality in host manipulation mimicked by serotonin injection.manipulative parasites often alter the phenotype of their hosts along multiple dimensions. 'multidimensionality' in host manipulation could consist in the simultaneous alteration of several physiological pathways independently of one another, or proceed from the disruption of some key physiological parameter, followed by a cascade of effects. we compared multidimensionality in 'host manipulation' between two closely related amphipods, gammarus fossarum and gammarus pulex, naturally and experimen ...201425339729
parasite-induced alteration of plastic response to predation threat: increased refuge use but lower food intake in gammarus pulex infected with the acanothocephalan pomphorhynchus laevis.larvae of many trophically-transmitted parasites alter the behaviour of their intermediate host in ways that increase their probability of transmission to the next host in their life cycle. before reaching a stage that is infective to the next host, parasite larvae may develop through several larval stages in the intermediate host that are not infective to the definitive host. early predation at these stages results in parasite death, and it has recently been shown that non-infective larvae of s ...201424291320
parasite-induced suppression of aggregation under predation risk in a freshwater amphipod: sociality of infected amphipods.recent findings suggest that grouping with conspecifics is part of the behavioural defences developed by amphipod crustaceans to face predation risk by fish. amphipods commonly serve as intermediate hosts for trophically transmitted parasites. these parasites are known for their ability to alter intermediate host phenotype in a way that promotes predation by definitive hosts, where they reproduce. if aggregation in amphipods dilutes the risk to be preyed on by fish, then it may dilute the probab ...201222940109
permanent genetic resources added to molecular ecology resources database 1 august 2009-30 september 2009.this article documents the addition of 238 microsatellite marker loci and 72 pairs of single nucleotide polymorphism (snp) sequencing primers to the molecular ecology resources database. loci were developed for the following species: adelges tsugae, artemisia tridentata, astroides calycularis, azorella selago, botryllus schlosseri, botrylloides violaceus, cardiocrinum cordatum var. glehnii, campylopterus curvipennis, colocasia esculenta, cynomys ludovicianus, cynomys leucurus, cynomys gunnisoni, ...201021565018
increased susceptibility to predation and altered anti-predator behaviour in an acanthocephalan-infected amphipod.according to the 'parasitic manipulation hypothesis', phenotypic changes induced by parasites in their intermediate hosts are effective means of increasing trophic transmission to final hosts. one obvious prediction, although seldom tested, is that increased vulnerability of infected prey to an appropriate predator should be achieved by the parasite altering the anti-predator behaviour of its intermediate host. in this study, we tested this prediction using the fish acanthocephalan pomphorhynchu ...200717258219
impact of an estrogenic sewage treatment plant effluent on life-history traits of the freshwater amphipod gammarus pulex.despite efforts to upgrade sewage treatment plants (stps) in the last decades, stps are still a major source for the contamination of surface waters, including emerging pollutants such as pesticides, pharmaceuticals, personal care products and endocrine disrupting chemicals (edcs). because many of these substances are not completely removed in conventional stps they are regularly detected in surface waters where they have the potential to affect local macroinvertebrate communities. the objective ...201525594120
predatory functional response and prey choice identify predation differences between native/invasive and parasitised/unparasitised crayfish.invasive predators may change the structure of invaded communities through predation and competition with native species. in europe, the invasive signal crayfish pacifastacus leniusculus is excluding the native white clawed crayfish austropotamobius pallipes.201222359673
biomonitoring with gammarus pulex at the meuse (nl), aller (ger) and rhine (f) rivers with the online multispecies freshwater biomonitor.biological early warning systems represent a set of tools that may be able to respond to certain chemical monitoring requirements of recent european legislation, the water framework directive (wfd2000/60/ec), that aims to improve and protect water quality across europe. in situ biomonitoring was performed along the rivers meuse (nl), aller (ger) and rhine (f) within the frame of the european union-funded project swift-wfd. gammarus pulex was used as a test organism during the evaluation of the m ...200717726559
effects of the cestode parasite, cyathocephalus truncatus, on the fecundity and feeding rate of gammarus pulex (crustacea: amphipoda).the amphipod gammarus pulex is an intermediate host to the cestode fish parasite cyathocephalus truncatus. in this study, we investigate effect of parasitism on female fecundity and feeding rate and compare ours results to those obtained previously with acanthocephalan parasite. similar reduction of the female fecundity was measured, whereas ours results on feeding rate were inconsistent, with a decrease of feeding rate induced by c. truncatus. the impacts of c. truncatus on g. pulex and similar ...201626545908
invaders, natives and their enemies: distribution patterns of amphipods and their microsporidian parasites in the ruhr metropolis, germany.the amphipod and microsporidian diversity in freshwaters of a heterogeneous urban region in germany was assessed. indigenous and non-indigenous host species provide an ideal framework to test general hypotheses on potentially new host-parasite interactions, parasite spillback and spillover in recently invaded urban freshwater communities.201526263904
pronounced and prevalent intersexuality does not impede the 'demon shrimp' invasion.crustacean intersexuality is widespread and often linked to infection by sex-distorting parasites. however, unlike vertebrate intersexuality, its association with sexual dysfunction is unclear and remains a matter of debate. the 'demon shrimp,' dikerogammarus haemobaphes, an amphipod that has invaded continental waterways, has recently become widespread in britain. intersexuality has been noted in d. haemobaphes but not investigated further. we hypothesise that a successful invasive population s ...201525699206
density-dependent effects on parasite growth and parasite-induced host immunodepression in the larval helminth pomphorhynchus laevis.larval helminths exploit the physiology of their intermediate hosts: first, as a resource for energy and space and second by altering the immune system activity to ensure their survival. whereas the growth pattern under parasite competition has been investigated, the effect of multiple infections on the level of parasite-induced immunodepression in a trophically transmitted helminth has been neglected. in this study, amphipods gammarus pulex were infected in the laboratory by the acanthocephalan ...201120696096
native and non-native plants provide similar refuge to invertebrate prey, but less than artificial plants.non-native species introductions are widespread and can affect ecosystem functioning by altering the structure of food webs. invading plants often modify habitat structure, which may affect the suitability of vegetation as refuge and could thus impact predator-prey dynamics. yet little is known about how the replacement of native by non-native vegetation affects predator-prey dynamics. we hypothesize that plant refuge provisioning depends on (1) the plant's native status, (2) plant structural co ...201525885967
acute toxicity of organic chemicals to gammarus pulex correlates with sensitivity of daphnia magna across most modes of action.we investigated the sensitivity of the freshwater crustacean amphipod gammarus pulex towards organic xenobiotic compounds in comparison to the sensitivity of the crustacean cladoceran daphnia magna. in addition we studied the influence of the chemical's mode of action on the relationship between the sensitivity of g. pulex and that of d. magna. we tested the acute toxicity of twelve compounds (malathion, aldicarb, carbofuran, 2,4-dichloroaniline, 2,4-dichlorophenol, 1,2,3-trichlorobenzene, 4,6-d ...201121392493
acute toxicity tests with daphnia magna, americamysis bahia, chironomus riparius and gammarus pulex and implications of new eu requirements for the aquatic effect assessment of insecticides.threshold concentrations for treatment related effects of 31 insecticides, as derived from aquatic micro-/mesocosm tests, were used to calibrate the predictive value of the european tier-1 acute effect assessment on basis of laboratory toxicity tests with daphnia magna, chironomus spp., americamysis bahia and gammarus pulex. the acute tier-1 effect assessment on basis of daphnia (ec(50)/100) overall was protective for organophosphates, carbamates and most pyrethroids but not for neonicotinoids a ...201222562347
toxicokinetic and toxicodynamic model for diazinon toxicity--mechanistic explanation of differences in the sensitivity of daphnia magna and gammarus pulex.a mechanistic toxicokinetic and toxicodynamic model for acute toxic effects (immobilization, mortality) of the organothiophosphate insecticide diazinon in daphnia magna is presented. the model was parameterized using measured external and internal (whole-body) concentrations of diazinon, its toxic metabolite diazoxon, and the inactive metabolite 2-isopropyl-6-methyl-4-pyrimidinol, plus acetylcholinesterase (ache) activity measured during exposure to diazinon in vivo. the toxicokinetic and toxico ...201222653849
population-level effects and recovery of aquatic invertebrates after multiple applications of an insecticide.standard risk assessment of plant protection products (ppp) combines "worst-case" exposure scenarios with effect thresholds using assessment (safety) factors to account for uncertainties. if needed, risks can be addressed applying more realistic conditions at higher tiers, which refine exposure and/or effect assessments using additional data. however, it is not possible to investigate the wide range of potential scenarios experimentally. in contrast, ecotoxicological mechanistic effect models do ...201626119989
derivation of a toxicity-based model to predict how water chemistry influences silver toxicity to invertebrates.the effect of altering water chemistry on acute silver toxicity to three invertebrate species, two daphnids, daphnia magna and daphnia pulex, as well as an amphipod gammarus pulex was assessed. in addition, the physiological basis of ag(i) toxicity to g. pulex was examined. daphnia magna and d. pulex were more sensitive than g. pulex and 48 h lc(50) values in synthetic ion poor water were 0.47, 0.65 and 2.1 microg ag(i) l(-1), respectively. increasing water [cl(-)] reduced ag(i) toxicity in all ...200212356532
a simple and rapid method for preserving rna of aquatic invertebrates for we describe a novel, inexpensive and simple method for preserving rna that reduces handling stress in aquatic invertebrates following ecotoxicogenomic experimentation. the application of the method is based on transcriptomic experiments conducted on daphnia magna, but may easily be applied on a range of other aquatic organisms of a particular size with e.g. amphipod gammarus pulex representing an upper size limit. we explain in detail how to apply this new method, named the "cylindrical sie ...200717530397
consequences of a short pulse of pesticide exposure for survival and reproduction of gammarus pulex.the aim of the present study was to examine the effects of a short and environmentally realistic pulse exposure of different life stages of the freshwater amphipod, gammarus pulex, to the pyrethroid insecticide, esfenvalerate. we were particularly interested in determining the extent to which detectable effects on key life-history traits persisted following cessation of a brief exposure to this pesticide. our results indicate that environmentally realistic exposure concentrations of this widely ...200415063077
predicting invasive species impacts: a community module functional response approach reveals context dependencies.predatory functional responses play integral roles in predator-prey dynamics, and their assessment promises greater understanding and prediction of the predatory impacts of invasive species. other interspecific interactions, however, such as parasitism and higher-order predation, have the potential to modify predator-prey interactions and thus the predictive capability of the comparative functional response approach. we used a four-species community module (higher-order predator; focal native or ...201525265905
comparative toxicokinetics of organic micropollutants in freshwater crustaceans.exposure and depuration experiments for gammarus pulex and daphnia magna were conducted to quantitatively analyze biotransformation products (btps) of organic micropollutants (tramadol, irgarol, and terbutryn). quantification for btps without available standards was performed using an estimation method based on physicochemical properties. time-series of internal concentrations of micropollutants and btps were used to estimate the toxicokinetic rates describing uptake, elimination, and biotransfo ...201323755888
toxic mixtures in time-the sequence makes the poison."the dose makes the poison". this principle assumes that once a chemical is cleared out of the organism (toxicokinetic recovery), it no longer has any effect. however, it overlooks the other process of re-establishing homeostasis, toxicodynamic recovery, which can be fast or slow depending on the chemical. therefore, when organisms are exposed to two toxicants in sequence, the toxicity can differ if their order is reversed. we test this hypothesis with the freshwater crustacean gammarus pulex an ...201728177231
do insect repellents induce drift behaviour in aquatic non-target organisms?synthetic insect repellents are compounds applied to surfaces to discourage insects, mainly mosquitoes, from landing on those surfaces. as some of these repellents have repeatedly been detected in surface waters at significant concentrations, they may also exert repellent effects on aquatic non-target organisms. in running water systems, aquatic invertebrates actively enter downstream drift in order to avoid unfavourable environmental conditions. we thus tested the hypothesis that the widely use ...201727838022
anthropogenic stressors shape genetic structure: insights from a model freshwater population along a land use gradient.environmental pollution including mutagens from wastewater effluents and discontinuity by man-made barriers are considered typical anthropogenic pressures on microevolutionary processes that are responsible for the loss of biodiversity in aquatic ecosystems. here, we tested for the effects of wastewater treatment plants (wwtps), weirs and other stressors on the invertebrate species gammarus pulex at the population genetic level combining evolutionary ecotoxicology, body burden analysis and testi ...201627643810
individual and joint toxicity of the herbicide s-metolachlor and a metabolite, deethylatrazine on aquatic crustaceans: difference between ecological groups.we studied the individual and joint acute toxicity of s-metolachlor (smoc) and deethylatrazine (dea - a metabolite of atrazine) on different non-target freshwater crustaceans. we used animals from different ecological groups: two amphipods from surface running water (gammarus pulex and gammarus cf. orinos), an isopod from surface stagnant water (asellus aquaticus) and an amphipod living in groundwater (niphargus rhenorhodanensis). organisms were exposed to different levels of smoc and dea, alone ...201627643657
impact of lambda-cyhalothrin on a macroinvertebrate assemblage in outdoor experimental channels: implications for ecosystem this study, the impact of a single pulse of the pyrethroid lambda-cyhalothrin was tested on a macroinvertebrate assemblage consisting of gammarus pulex, leuctra nigra, heptagenia sulphurea and ancylus fluviatilis in outdoor experimental stream channels. channels (4m long, 0.1m wide) were groundwater fed and had natural substratum. macroinvertebrates were exposed to 10.65 or 106.5 ng l(-1) lambda cyhalothrin for 90 min in the laboratory and after 24h introduced to the experimental stream chann ...200818945499
corrigendum to "transcriptome of the freshwater amphipod gammarus pulex hepatopancreas" [genomics data 8 (2016) 91-92].[this corrects the article doi: 10.1016/j.gdata.2016.04.002.].201627642567
antagonistic effects of biological invasion and environmental warming on detritus processing in freshwater biodiversity is threatened by multiple anthropogenic stressors but little is known about the combined effects of environmental warming and invasive species on ecosystem functioning. we quantified thermal preferences and then compared leaf-litter processing rates at eight different temperatures (5.0-22.5 °c) by the invasive freshwater crustacean dikerogammarus villosus and the great britain native gammarus pulex at a range of body sizes. d. villosus preferred warmer temperatures but there ...201728013390
glacial-driven vicariance in the amphipod gammarus duebeni.we have examined the genetic diversity using mitochondrial coi and nd2 sequence data from 306 specimens of the amphi-atlantic-distributed amphipod gammarus duebeni. marine populations from the atlantic ocean, the baltic and north sea, as well as freshwater populations from ireland, cornwall and brittany were analysed. g. duebeni is a complex of five allopatric lineages. freshwater populations result from multiple invasions of marine ancestors, represented by distinct lineages. we interpret the r ...201019654046
microtubule systems associated with the septate junctions of the gill cells of four gammarid amphipods.the microtubular systems associated with the septate junctions of the gill epithelial cells of four species of gammarid amphipod are described. the four species examined included two relatively stenohaline marine forms, chaetogammarus marinus and gammarus locusta; a highly euryhaline species, gammarus duebeni, and a stenohaline freshwater species, gammarus pulex. of these amphipods, g. locusta and c. marinus maintain only a limited osmotic gradient between their haemolymph and the medium and hav ...199518621295
data for comparative proteomics of ovaries from five non-model, crustacean amphipods.ovaries were taken from five sexually mature amphipods: gammarus fossarum, gammarus pulex, gammarus roeseli, hyallela azteca and parhyale hawaiensis. the soluble proteome extracted from individual pair of ovaries from five biological replicates was trypsin digested and the resulting peptides were analyzed by high resolution tandem mass spectrometry. the spectra were assigned with four protein sequence databases with different specificities: a rnaseq-derived g. fossarum database; a rnaseq-derived ...201526380837
a comparison of the short-term toxicity of cadmium to indigenous and alien gammarid species.amphipods play an important role in many aquatic ecosystems and are commonly used in ecotoxicology and ecosystem health assessment. several alien gammarids have been introduced in many regions of the world during the last decades. in this study, we investigated if differences in cadmium sensitivity occurred between (1) different species belonging to the family gammaridae and (2) different populations of the same species originating from a polluted or a non-polluted site. the acute cadmium toxici ...201222354564
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