Search results for "Host-parasite interactions"
showing 10 items of 330 documents
Seasonal changes in host phenotype manipulation by an acanthocephalan: time to be transmitted?
2009
Parasitology, 136 (2)
THE BEHAVIORAL RESPONSE OF AMPHIPODS HARBORING CORYNOSOMA CONSTRICTUM (ACANTHOCEPHALA) TO VARIOUS COMPONENTS OF LIGHT
2006
Many studies have shown that photic behavior of amphipods is subject to parasitic manipulation. However, all these investigations have focused on but one property of light (i.e., intensity). This study investigated the possibility that variable wavelength sensitivity, as a potentially important component of amphipod ecology, is subject to parasitic manipulation. The photic behavior of freshwater amphipods Hyalella azteca, infected with the duck acanthocephalan Corynosoma constrictum, was tested. The phototactic responses of infected and uninfected amphipods to various wavelengths in the visible spectrum were compared, and to delineate the effects of intensity and wavelength on behavior, the…
Carotenoids of two freshwater amphipod species (Gammarus pulex and G. roeseli) and their common acanthocephalan parasite Polymorphus minutus
2004
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 non-polar compounds were identified. Seven kinds of carotenoids, mainly xanthophylls, were identified in gammarids. Astaxanthin was predominant, amounting to 40 wt.% of total carotenoid in both uninf…
Cercarial Production of the Trematode Rhipidocotyle fennica in Clams Kept in the Field
1998
The numbers of cercariae that trematodes produce have been previously investigated in the laboratory but not in the field. I studied cercarial production of the bucephalid trematode Rhipidocotyle fennica in the freshwater unionid clam Anodonta piscinalis kept under natural conditions. Naturally infected clams (n = 180) were collected and marked in early June 1996. Every 14 days, starting from the collection date and ending in October, these clams were taken to the laboratory where they were monitored for the emergence of trematode cercariae. Between monitoring dates, the clams were returned to the collection site. From a random subsample of infected clams (n = 12), the number of cercariae p…
Relatedness affects competitive performance of a parasitic plant (Cuscuta europaea) in multiple infections.
2004
Theoretical models predict that parasite relatedness affects the outcome of competition between parasites, and the evolution of parasite virulence. We examined whether parasite relatedness affects competition between parasitic plants (Cuscuta europaea) that share common host plants (Urtica dioica). We infected hosts with two parasitic plants that were either half-siblings or nonrelated. Relative size asymmetry between the competing parasites was significantly higher in the nonrelated infections compared to infections with siblings. This higher asymmetry was caused by the fact that the performance of some parasite genotypes decreased and that of others increased when grown in multiple infect…
Burrowing behaviour affects Paraergasilus rylovi abundance in Anodonta piscinalis.
2006
Burrowing depth may affect predation rate, feeding ability and reproduction in bivalve clams. We studied the effect of burrowing depth on the abundance of the ergasilid Paraergasilus rylovi in the freshwater bivalve clam Anodonta piscinalis. We transplanted uninfected clams to a lake where they were allowed to choose their preferred burrowing depth, and were exposed naturally to copepodids of the parasite. There was a significant positive correlation between proportionate burrowing depth (PBD) and the abundance of P. rylovi at the end of the 17-day experiment, the deeper-burrowed clams harbouring more P. rylovi. Original PBD (0%, 50%, 100%) did not influence the final PBD or parasite abunda…
Climate change and the ecology and evolution of Arctic vertebrates.
2012
25 pages; International audience; Climate change is taking place more rapidly and severely in the Arctic than anywhere on the globe, exposing Arctic vertebrates to a host of impacts. Changes in the cryosphere dominate the physical changes that already affect these animals, but increasing air temperatures, changes in precipitation, and ocean acidification will also affect Arctic ecosystems in the future. Adaptation via natural selection is problematic in such a rapidly changing environment. Adjustment via phenotypic plasticity is therefore likely to dominate Arctic vertebrate responses in the short term, and many such adjustments have already been documented. Changes in phenology and range w…
Nyctiphanes couchii as intermediate host for Rhadinorhynchus sp. (Acanthocephala, Echinorhynchidae) from NW Iberian Peninsula waters
2013
12 páginas, 3 figuras, 3 tablas
The role of contact chemoreception in the host location process of an egg parasitoid
2016
Taste allows insects to detect palatable or toxic foods, identify a mate, and select appropriate oviposition sites. The gustatory system strongly contributes to the survival and reproductive success of many species, yet it is rarely studied in insect parasitoids. In order to locate and assess a host in which they will lay their eggs, female wasps actively search for chemical cues using their sensory organs present mainly on the antennae. In this paper, we studied the role of antennal taste sensilla chaetica in the perception of contact semiochemicals in Trissolcus brochymenae (Hymenoptera: Platygastridae), an egg parasitoid of the brassicaceae pest Murgantia histrionica (Heteroptera: Pentat…
Phylogenetic analysis of Lymnaeid snails based on 18S rDNA sequences.
1997
The 18S rDNA sequences of the six most common European Lymnaeidae species (Mollusca:Gastropoda:Basommatophora) have been obtained by direct PCR cycle sequencing and silver staining methods. The sequence alignment and secondary structures of the 18S rRNA gene of Lymnaea stagnalis, L. auricularia, L. peregra, L. palustris, L. glabra, and L. truncatula are analyzed. This gene proves to be a good marker for both specific determination and supraspecific lymnaeid phylogeny. The malacological importance is evident, considering the specific determination problems of individual snails and the present systematic chaos in Lymnaeidae due to their pronounced morphoanatomic uniformity, which makes a clas…