Daphnia pulex de Geer and Daphnia magna Straus populations cannot be maintained in defined (sensu stricto) media containing less than 0.1 part per billion (ppb) of selenium. A concentration of 1 ppb is sufficient to satisfy minimal needs in otherwise sufficient media. In the first generation with no selenium added to the medium or detected in it, media deficiency is shown by a premature cuticle...

Global climate change, natural disasters and anthropogenic modifications of waterways may all lead to changing water temperature patterns in aquatic systems. We assessed the effects of different water temperatures on the reproductive rates of Daphnia pulex, a common primary consumer in aquatic ecosystems. Life table experiments were conducted using animals acclimatized to 10 ¡C and 20 ¡C water ...

The acute toxicity of Tl(I) to the microalga, Pseudokirchneriella subcapitata, the planktonic crustaceans, Daphnia magna and Daphnia pulex, and early-life stage of the zebrafish, Danio rerio, has been studied according to OECD protocols. Toxicological end-point concentrations for the microalga ranged from 17 μg l(-1) for a 72 h EyC25 (yield inhibition) to 80 μg l(-1) for a 72 h ErC50 (growth in...

BACKGROUND With the emergence of a completed genome sequence of the freshwater crustacean Daphnia pulex, construction of genomic-scale sequence databases for additional crustacean sequences are important for comparative genomics and annotation. Porcelain crabs, genus Petrolisthes, have been powerful crustacean models for environmental and evolutionary physiology with respect to thermal adaptati...

Whether speciation can advance to completion in the face of initially high levels of gene flow is a very controversial topic in evolutionary biology. Extensive gene exchange is generally considered to homogenize populations and counteract divergence. Moreover, the role of introgressive hybridization in evolution remains largely unexplored in animals, particularly in freshwater zooplankton in wh...

The aim of our study was to analyze the presence of 5-methyl-cytosine (5-mC) and 5-hydroxymethyl-cytosine (5-hmC) in the genome of crustacean Daphnia pulex. First, the presence of 5-mC and 5-hmC in genomic DNA was demonstrated by using antibodies specific to either 5-mC or 5-hmC. Then, analysis of 5-mC and 5-hmC using pairs of restriction enzymes with different sensitivity to methylation and hy...