The identification of interacting species and elucidation of their mode of interaction may be crucial to understand ecosystem-level processes. We analysed the activity and identity of bacterial epibionts in cultures of Daphnia galeata and of natural daphnid populations. Epibiotic bacteria incorporated considerable amounts of dissolved organic carbon (DOC), as estimated via uptake of tritiated l...

Unusual behavior before earthquakes has been reported for millennia but no plausible mechanism has been identified. One possible way in which animals could be affected by pre-earthquake processes is via stress activated positive holes leading to the formation of hydrogen peroxide at the rock water interface. Aquatic and fossorial animals could be irritated by H₂O₂ and move down the concentratio...

The growth rate hypothesis (GRH) proposes that variation in organism C : P and N : P ratios reflects variation in P content associated with altered allocation to P-rich ribosomal RNA under different growth rates. We tested the GRH by examining the effects of food quantity and stoichiometric quality (differing carbon : nitrogen : phosphorus [C : N : P] ratios) on juvenile growth and chemical com...

Despite the great utility of mitochondrial DNA (mtDNA) sequence data in population genetics and phylogenetics, key parameters describing the process of mitochondrial mutation (e.g., the rate and spectrum of mutational change) are based on few direct estimates. Furthermore, the variation in the mtDNA mutation process within species or between lineages with contrasting reproductive strategies rem...

Species interactions are often suggested as an important factor when assessing the effects of chemicals on higher levels of biological organization. Nevertheless, the contribution of intraspecific and interspecific interactions to chemical effects on populations is often overlooked. In the present study, Daphnia magna populations were initiated with different levels of intraspecific competition...

Several pharmaceutical compounds have been detected in natural aqueous systems and ibuprofen (IBF), one of the most consumed medicament, has been detected in many countries. The degradation efficiency of IBF under TiO2/UV radiation was evaluated. Optimum degradation results were observed using 20 mg∙L−1 of TiO2, pH 7.8 and 5 mg∙L−1 of IBF. Under these experimental conditions total IBF removal w...

background: the problem of the environmental pollution by nanoparticles, which have recently entered the cycle of industries process in iran, is very important and can be prevented with applying the proper management approaches. one of the most practical compounds is zno nanoparticle. in the present study  the (lethal concentration-50) lc50 24hr and 48hr of zno nanoparticles exposed-to reactive...

In this article we propose a Bayesian hierarchical model for the identification of differentially expressed genes in Daphnia magna organisms exposed to chemical compounds, specifically munition pollutants in water. The model we propose constitutes one of the very first attempts at a rigorous modeling of the biological effects of water purification. We have data acquired from a purification syst...

We investigated the intestinal uptake and adverse effects of microcystins ingested with Microcystis on Daphnia galeata. The gut structure, blood microcystin concentration, appearance, and movements of Daphnia fed Microcystis PCC 7806 or a microcystin-deficient PCC 7806 mutant were monitored over time. Microcystins were rapidly taken up from the digestive cavity into the blood. This process appa...