Search results for "Parasite"
showing 10 items of 827 documents
Effect of pulp and paper mill effluent (BKME) on physiological parameters of roach (Rutilus rutilus) infected by the digenean Rhipidocotyle fennica.
2002
Physiological parameters were measured after experimental infection of roach (Rutilus rutilus L.) with Rhipidocotyle fennica Gibson, Valtonen et Taskinen, 1992 (Digenea) cercariae. The fish were caught from two lakes: a eutrophic bleached kraft mill effluent (BKME)-contaminated lake and an oligotrophic unpolluted lake. The intensity of infection was followed up to 10 days post infection (p.i.) and physiological parameters indicating non-specific stress responses and the condition of fish were examined simultaneously. The mean abundance, the number of parasites per fish, of R. fennica was significantly higher in the fish from the contaminated water during the first two days p.i., probably re…
Data from: Getting there and around: host range oscillations during colonisation of the Canary Islands by the parasitic nematode Spauligodon
2017
Episodes of expansion and isolation in geographic range over space and time, during which parasites have the opportunity to expand their host range, are linked to the development of host-parasite mosaic assemblages and parasite diversification. In this study we investigated whether island colonisation events lead to host range oscillations in a taxon of host-specific parasitic nematodes of the genus Spauligodon in the Canary Islands. We further investigated if range oscillations also resulted in shifts in host breadth (i.e. specialization), as expected for parasites on islands. Parasite phylogeny and divergence time estimates were inferred from molecular data with Bayesian methods. Host div…
Parasite communities as indicators of recovery from pollution: parasites of roach (Rutilus rutilus) and perch (Perca fuviatilis) in central Finland.
2003
We compared parasite communities in fish taken from a polluted lake (L. Vatia) and two control lakes before (1986) and after (1995) nine years of markedly reduced chemical and nutrient loading from a pulpmill in central Finland. Discriminant analyses of the 1995 data, using a function based on the 1986 data, showed that the parasite communities in the fish from the two control lakes had changed relatively little, whereas those from L. Vatia had converged on those from the mesotrophic control lake, indicating substantial recovery from the effects of pollution. Only a few species of parasites provided evidence for recovery. These were anodontid glochidia, which had increased markedly in perch…
Within-lake dynamics in the similarity of parasite assemblages of perch (Perca fluviatilis).
2005
Although parasite communities have been studied extensively in recent years, spatial and temporal variation in factors affecting the communities has received less attention. This paper examined the similarity of parasite assemblages of perch (Perca fluviatilis) in 18 locations within a single lake in relation to geographical distance and temporal dynamics in the host and parasite populations. We expected that in the present study-scale where distinct but potentially interacting host subpopulations could occur, similarity of the assemblages could be affected by seasonal dynamics in host movements particularly during the spawning period. Parasite species showed differences in infection levels…
Zschokkella hildae Auerbach, 1910: phylogenetic position, morphology, and location in cultured Atlantic cod.
2010
Abstract The myxozoan Zschokkella hildae Auerbach, 1910, was detected with a prevalence of 100% in cultured Atlantic cod, Gadus morhua L. aged 1+ from a culture facility on the west coast of Scotland. Sporogonic stages of Z. hildae, plasmodia producing 2–5 mature spores, were located predominantly in the collecting ducts and ureters of the kidney, and spores were present in the urine collected from the bladder. Less frequently, plasmodia were detected in the interstitial tissue of the kidney. The parasite prevalence in cultured fish was considerably higher than reported in wild fish but no obvious signs of pathology were detected. SSU rDNA sequencing and phylogenetic analysis showed that Z.…
Parasite specificity in Podarcis bocagei and P. carbonelli (Lacertidae) from NW Portugal: a host-parasite history
2015
Host parasite specificity is related to several factors including the type of life cycle of the parasite, the habitat occupied by both parasites and hosts, and the food habits of the hosts. In this work, gastrointestinal helminths in two congeneric lacertid lizards, Podarcis bocagei and Podarcis carbonelli living in sintopy, have been analysed. Out of four helminth species found, three of them, the trematode Brachylaima sp., the cestode Oochoristica gallica and the nematode Skrjabinelazia hoffmanni, have indirect life cycles while the nematode Spauligodon carbonelli has a direct life cycle. Heteroxenous helminths showed low host specificity whereas S. carbonelli may be placed at an intermed…
Collective defence portfolios of ant hosts shift with social parasite pressure
2014
Host defences become increasingly costly as parasites breach successive lines of defence. Because selection favours hosts that successfully resist parasitism at the lowest possible cost, escalating coevolutionary arms races are likely to drive host defence portfolios towards ever more expensive strategies. We investigated the interplay between host defence portfolios and social parasite pressure by comparing 17 populations of two Temnothorax ant species. When successful, collective aggression not only prevents parasitation but also spares host colonies the cost of searching for and moving to a new nest site. However, once parasites breach the host's nest defence, host colonies should resor…
Patterns of cercarial production from Diplostomum spathaceum: terminal investment or bet hedging?
2004
In the production of the infective cercariae of trematodes, the terminal investment hypothesis of life-history theory predicts that the rate of host exploitation and cercarial production should increase during the period of cercarial shedding since the reproductive value of the parasite decreases during this period. In contrast, a bet hedging hypothesis that focuses on the success of transmission when host contact rate is variable predicts that cercarial production should decrease in an attempt to keep the host alive for longer and thus would increase the probability of successful transmission. We examined these two hypotheses under laboratory conditions and recorded the production ofDiplos…
Increased Vascularity in Cervicovaginal Mucosa with Schistosoma haematobium Infection
2011
Background Close to 800 million people in the world are at risk of schistosomiasis, 85 per cent of whom live in Africa. Recent studies have indicated that female genital schistosomiasis might increase the risk of human immunodeficiency virus (HIV) infection. The aim of this study is to quantify and analyse the characteristics of the vasculature surrounding Schistosoma haematobium ova in the female genital mucosa. Methodology/Principal Findings Cervicovaginal biopsies with S. haematobium ova (n = 20) and control biopsies (n = 69) were stained with immunohistochemical blood vessel markers CD31 and von Willebrand Factor (vWF), which stain endothelial cells in capillary buds and established blo…
Real-Time Polymerase Chain Reaction for Detection of Schistosoma DNA in Small-Volume Urine Samples Reflects Focal Distribution of Urogenital Schistos…
2014
Schistosoma haematobium eggs and Schistosoma DNA levels were measured in urine samples from 708 girls recruited from 18 randomly sampled primary schools in South Africa. Microscopic analysis of two 10-mL urine subsamples collected on three consecutive days confirmed high day-to-day variation; 103 (14.5%) girls had positive results at all six examinations, and at least one positive sample was seen in 225 (31.8%) girls. Schistosoma-specific DNA, which was measured in a 200-μL urine subsample by using real-time polymerase chain reaction, was detected in 180 (25.4%) cases, and levels of DNA corresponded significantly with average urine egg excretion. In concordance with microscopic results, pol…