The faecal indicator Escherichia coli plays a central role in water quality assessment and monitoring. It is therefore essential to understand its fate under various environmental constraints such as predation by bacterivorous zooplankton. Whereas most studies have examined how protozooplankton communities (heterotrophic nanoflagellates and ciliates) affect the fate of E. coli in water, the cap...

Although per capita rates of increase (r) have been calculated by population biologists for decades, the inability to estimate uncertainty (variance) associated with r values has until recently precluded statistical comparisons of population growth rates. In this study, we used two computerintensive techniques, Jackknifing and Bootstrapping, to estimate bias, standard errors, and sampling distr...

1 Large-scale TSS profiling produces a high-resolution, quantitative picture of transcription initiation 2 and core promoter locations within a genome. However, application of TSS profiling to date has 3 largely been restricted to a small set of prominent model systems. We sought to characterize the 4 cis-regulatory landscape of the water flea Daphnia pulex, an emerging model arthropod that rep...

This study aimed at investigating both the individual and combined effects of cadmium (Cd) and arsenate (AsV) on the physiology and behaviour of the Crustacean Gammarus pulex at three temperatures (5, 10 and 15 °C). G. pulex was exposed during 96 h to (i) two [Cd] alone, (ii) two [AsV] alone, and (iii) four combinations of [Cd] and [AsV] to obtain a complete factorial plane. After exposure, sur...

Here, we report 2 novel intron gains segregating in populations of Daphnia pulex endemic to Oregon. These novel introns do not have an obvious source and are not present in any D. pulex populations outside Oregon, other species of Daphnia that we examined, or any other organism for which sequence data are available. Furthermore, the novel introns are both found in the same gene, a Rab GTPase (r...

Longevity is a highly variable life history trait and its variation is attributable to both genetic and environmental factors. Exploring well-known environmental factors in a new model system is a useful approach to explore taxonomic variation in plasticity of longevity. We examined responsiveness of the Daphnia pulex clone TCO to potentially related interventions that have been reported to ext...

The fourth Daphnia Genomics Consortium Meeting was held from July 7th through July 9th, 2007 at Indiana University (Bloomington, IN, USA). This year’s meeting was entitled The Genome Biology of the Model Crustacean Daphnia and was highlighted by the initial public release of the draft version of the Daphnia pulex genome. In collaboration with the US Department of Energy Joint Genome Institute (...

Behavioural responses of invasive animals to biotic interactions can inform predictions of their consumptive impacts; however, such biotic contexts are often overlooked. Here, we assessed the interacting effect of conspecific and higher-order predation risk on the per capita consumption and behaviours of the invasive freshwater amphipod Gammarus pulex, using field microcosm and video-recorded l...

Biomonitoring, assumed to be an integrative measurement of the chemical exposure of aquatic organisms, is not straightforward for essential metals because they can be actively regulated by animals. Although increasing bioaccumulation with exposure levels is a crucial endpoint for the development of biomonitors, it is rarely verified in real environments, where the metal concentrations are rathe...

Despite much theoretical work, the molecular-genetic causes and evolutionary consequences of asexuality remain largely undetermined. Asexual animal species are rare, evolutionarily short-lived, and thought to suffer mutational meltdown as a result of lack of recombination. Whole-genome analysis of 11 sexual and 11 asexual genotypes of Daphnia pulex indicates that current asexual lineages are in...