Search results for "Gammarus fossarum"
showing 4 items of 4 documents
Origin of the natural variation in the storage of dietary carotenoids in freshwater amphipod crustaceans
2020
16 pages; International audience; Carotenoids are diverse lipophilic natural pigments which are stored in variable amounts by animals. Given the multiple biological functions of carotenoids, such variation may have strong implications in evolutionary biology. Crustaceans such as Gammarus amphipods store large amounts of these pigments and inter-population variation occurs. While differences in parasite selective pressure have been proposed to explain this variation, the contribution of other factors such as genetic differences in the gammarid ability to assimilate and/or store pigments, and the environmental availability of carotenoids cannot be dismissed. This study investigates the relati…
Confrontation of cryptic diversity and mate discrimination within Gammarus pulex and Gammarus fossarum species complexes.
2014
16 pages; International audience; Freshwater amphipods Gammarus fossarum and Gammarus pulex are widespread in Europe, with some evidence of cryptic diversity in the former. We used DNA barcoding to assess genetic diversity within and among amphipod populations and examined mate discrimination and pre-copulatory pair formation between genetically divergent individuals. Eight distinct G. fossarum and four distinct G. pulex molecular operational taxonomic units (MOTUs) were detected. Among the 33 amphipod populations sampled, 11 contained a single MOTU, 11 had two and 11 were composed of three sympatric MOTUs. Genetic divergences between sympatric MOTUs (G. fossarum and G. pulex MOTUs combined…
Shaping the antipredator strategy: flexibility, consistency, and behavioral correlations under varying predation threat
2014
9 pages; International audience; Recent ecological and evolutionary research emphasizes the importance of adaptive trait integration. For instance, antipredator defenses are built up of several morphological and behavioral components in many species, yet their functional relationships are still poorly documented. Using field-collected freshwater crustaceans Gammarus fossarum in a within-subject design, we investigated the flexibility and consistency of refuge use, photophobia, and exploration behavior as well as their associations, quantified both when predation risk was absent or artificially simulated. In agreement with the "threat-sensitivity" hypothesis, both refuge use and photophobia …
Data from: Multidimensionality in host manipulation mimicked by serotonin injection
2014
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 experimentally infected with Pomphorhynchus laevis (Acanthocephala), respectively. To that end, we calculated in each host–parasite association the effect size of the difference between infected and uninfecte…