Search results for "gammarids"
showing 3 items of 3 documents
Neogene paleogeography provides context for understanding the origin and spatial distribution of cryptic diversity in a widespread Balkan freshwater …
2017
BackgroundThe Balkans are a major biodiversity and endemism hotspot, worldwide. Among the freshwater biota, amphipods are known for their high cryptic diversity. However, little is known about the temporal and paleogeographic aspects of their evolutionary history. We used paleogeography as a framework for understanding the onset of diversification inGammarus roeselii: (1) we hypothesised that, given the high number of isolated waterbodies in the Balkans, the species is characterised by high level of cryptic diversity, even on a local scale; (2) the long geological history of the region might promote pre-Pleistocene divergence between lineages; (3) given thatG. roeseliithrives both in lakes …
The effects of parasite age and intensity on variability in acanthocephalan-induced behavioural manipulation.
2008
10 pages; International audience; 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 individuals being strongly manipulated whilst others are almost not affected by infection. To investigate parasite age and parasite intensity as potential sources o…
Pairing success and sperm reserve of male Gammarus pulex infected by Cyathocephalus truncatus (Cestoda: Spathebothriidea).
2011
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 considered 3 classes of G. pulex males in our experiments: (i) uninfected males found paired in the field, (ii) uninfected males found unpaired in the field, or (iii) infected males found unpaired i…