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Margarida Castro, Verónica Nogueira, Isabel Lopes, Maria N Vieira, Teresa Rocha-Santos, Ruth Pereira
This study aimed to explore the efficiency of two adsorbents, cork granules with different granulometry and titanium dioxide nanomaterial, in the removal of chemical oxygen demand (COD), colour and toxicity from a textile effluent. The adsorption assays with cork were unsatisfactory in the removal of chemical parameters however they eliminated the acute toxicity of the raw effluent to Daphnia magna. The assay with TiO2 NM did not prove to be efficient in the removal of colour and COD even after 240 min of contact; nevertheless it also reduced the raw effluent toxicity...
January 18, 2018: Journal of Environmental Science and Health. Part A, Toxic/hazardous Substances & Environmental Engineering
Nina Gerber, Hanna Kokko, Dieter Ebert, Isobel Booksmythe
The timing of sex in facultatively sexual organisms is critical to fitness, due to the differing demographic consequences of sexual versus asexual reproduction. In addition to the costs of sex itself, an association of sex with the production of dormant life stages also influences the optimal use of sex, especially in environments where resting eggs are essential to survive unfavourable conditions. Here we document population dynamics and the occurrence of sexual reproduction in natural populations of Daphnia magna across their growing season...
January 31, 2018: Proceedings. Biological Sciences
Linda C Weiss, Leonie Pötter, Annika Steiger, Sebastian Kruppert, Uwe Frost, Ralph Tollrian
Anthropogenically released CO2 accumulates in the global carbon cycle and is anticipated to imbalance global carbon fluxes [1]. For example, increased atmospheric CO2 induces a net air-to-sea flux where the oceans take up large amounts of atmospheric CO2 (i.e., ocean acidification [2-5]). Research on ocean acidification is ongoing, and studies have demonstrated the consequences for ecosystems and organismal biology with major impacts on marine food webs, nutrient cycles, overall productivity, and biodiversity [6-9]...
January 9, 2018: Current Biology: CB
Melanie Raby, Monica Nowierski, Dmitri Perlov, Xiaoming Zhao, Chunyan Hao, David G Poirier, Paul K Sibley
Neonicotinoids are a group of insecticides commonly used in agriculture. Due to their high water solubility, neonicotinoids can be transported to surface waters and have the potential to be toxic to aquatic life. The present study assessed and compared the acute (48 or 96 h) toxicity of 6 neonicotinoids (acetamiprid, clothianidin, dinotefuran, imidacloprid, thiacloprid, and thiamethoxam) to 21 laboratory-cultured and field-collected aquatic invertebrates spanning 10 aquatic arthropod orders. Test conditions mimicked species' habitat, with lentic taxa exposed under static conditions, and lotic taxa using recirculating exposure systems...
January 16, 2018: Environmental Toxicology and Chemistry
Mikael T Ekvall, Jonas Hedberg, Inger Odnevall Wallinder, Lars-Anders Hansson, Tommy Cedervall
As the production and usage of nanomaterials are increasing so are the concerns related to the release of the material into nature. Tungsten carbide (WC) is widely used for its hard metal properties, although its use, in for instance tyre studs, may result in nano-sized particles ending up in nature. Here, we evaluate the potential long-term exposure effects of WC nanoparticles on a pelagic (Daphnia magna) and a benthic (Asellus aquaticus) organism. No long-term effects were observed in the benthic system with respect to population dynamics or ecosystem services...
January 15, 2018: Nanotoxicology
Ryeo-Ok Kim, Min-A Jo, Jinhaeng Song, Il-Chan Kim, Seokjoo Yoon, Woo-Keun Kim
Because of its widespread use, the pharmaceutical acetaminophen (APAP) is frequently detected in aquatic environments. APAP can have serious physiological effects, such as reduced reproduction, low growth rates, and abnormal behavior, in aquatic organisms. However, the methods available for evaluation of the aquatic toxicity of APAP are of limited usefulness. The present study aimed to develop reliable and sensitive markers for evaluation of APAP toxicity using Daphnia as a model organism. We focused on N-acetyl-p-benzoquinoneimine (NAPQI) production from APAP via cytochrome P450 metabolism because NAPQI causes APAP toxicity...
December 30, 2017: Aquatic Toxicology
Anastasia V Simakova, Yuri S Tokarev, Irma V Issi
Infection with a new microsporidium, Fibrillaspora daphniae g. n. sp. n., was found in a local Daphnia magna population in Tomsk region (Western Siberia, Russia) at the prevalence rate of 52%. Histological sections showed parasite cells entirely encompassing the host haemocoel. Methanol-fixed spores were elongate, oval, 4.8 ± 0.3 μm × 2.3 ± 0.2 μm in size. All developmental stages were in direct contact with the host cell cytoplasm, with single nuclei, and division by binary fission. The sporont surface was covered with an additional outer layer composed of fine tubules...
January 10, 2018: Parasitology Research
Yooeun Chae, Dokyung Kim, Shin Woong Kim, Youn-Joo An
This study investigated the trophic transfer, individual impact, and embryonic uptake of fluorescent nano-sized polystyrene plastics (nanoplastics) through direct exposure in a freshwater ecosystem, with a food chain containing four species. The alga Chlamydomonas reinhardtii, water flea Daphnia magna, secondary-consumer fish Oryzias sinensis, and end-consumer fish Zacco temminckii were used as test species. In the trophic transfer test, algae were exposed to 50 mg/L nanoplastics, defined as plastic particles <100 nm in diameter; higher trophic level organisms were exposed through their diet...
January 10, 2018: Scientific Reports
Claudia Ferrario, Marco Parolini, Beatrice De Felice, Sara Villa, Antonio Finizio
The main objective of the present study was to investigate possible links between sub-individual and supra-individual levels (i.e. population level) biomarkers in D. magna exposed to sublethal concentrations of the insecticide chlorpyrifos (CPF). To achieve the aim, 8-day old individuals were exposed for 96 h to two environmentally relevant concentrations of CPF (50 and 250 ng/L). Sub-individual level effects were investigated by measuring the activity of antioxidant (SOD, CAT, and GPx) and detoxifying (GST) enzymes, as well as by measuring the acetylcholinesterase (AChE) inhibition...
January 4, 2018: Environmental Pollution
Ryan E Sherman, Priyanka Roy Chowdhury, Kristina D Baker, Lawrence J Weider, Punidan D Jeyasingh
The framework ecological stoichiometry uses elemental composition of species to make predictions about growth and competitive ability in defined elemental supply conditions. Although intraspecific differences in stoichiometry have been observed, we have yet to understand the mechanisms generating and maintaining such variation. We used variation in phosphorus (P) content within a Daphnia species to test the extent to which %P can explain variation in growth and competition. Further, we measured 33P kinetics (acquisition, assimilation, incorporation and retention) to understand the extent to which such variables improved predictions...
December 2017: Royal Society Open Science
Simon Kresmann, Arokia Hansel Rajan Arokia, Christoph Koch, Bernd Sures
The use of biocides by industry, agriculture and households increased throughout the last two decades. Many new applications with known substances enriched the variety of biocidal pollution sources for the aquatic environment. While agriculture was the major source for a long time, leaching from building facades and preservation of personal care and cleaning products was identified as new sources in the last few years. With the different usage forms of biocidal products the complexity of legislative regulation increased as well...
January 4, 2018: Science of the Total Environment
Xiaoxue Xu, Ya-Nan Zhang, Shuixiu Peng, Jianxun Wu, Daogui Deng, Zhongze Zhou
Nuclear receptor (NR) genes form a conserved superfamily, which is involved in organism metabolism, reproduction, development, homeostasis, and resource allocation. Microcystis aeruginosa can inhibit the growth and reproduction of Daphnia. However, whether M. aeruginosa can affect the expression of Daphnia NR genes is unknown. In total, 18 NRs were identified in this study based on previous Daphnia similoides sinensis transcriptome data. In treatments containing M. aeruginosa, the gene expression of the NR1 subfamily (E75a, E75b, HR3, HR96, NHR-1, HR97a, HR97g, and NHR97) and the NR2 subfamily (RXR, TLL, PNR, and SVP) were down-regulated 59% and 79%, respectively...
January 3, 2018: Ecotoxicology and Environmental Safety
Xiangrui Wang, Jianyu Liu, Qiaoguo Tan, Jinqian Ren, Dingyuan Liang, Wenhong Fan
Despite the great progress made in metal-induced toxicity mechanisms, a critical knowledge gap still exists in predicting adverse effects of heavy metals on living organisms in the natural environment, particularly during exposure to multi-metals. In this study, a multi-metal interaction model of Daphnia manga was developed in an effort to provide reasonable explanations regarding the joint effects resulting from exposure to multi-metals. Metallothionein (MT), a widely used biomarker, was selected. In this model, MT was supposed to play the role of a crucial transfer protein rather than detoxifying protein...
January 3, 2018: Ecotoxicology and Environmental Safety
Maria Cuenca Cambronero, Bettina Zeis, Luisa Orsini
Anthropogenic global warming has become a major geological and environmental force driving drastic changes in natural ecosystems. Due to the high thermal conductivity of water and the effects of temperature on metabolic processes, freshwater ecosystems are among the most impacted by these changes. The ability to tolerate changes in temperature may determine species long-term survival and fitness. Therefore, it is critical to identify coping mechanisms to thermal and hyper-thermal stress in aquatic organisms...
January 2018: Evolutionary Applications
Eyerusalem Goitom, Laurens J Kilsdonk, Kristien Brans, Mieke Jansen, Pieter Lemmens, Luc De Meester
There is growing evidence of rapid genetic adaptation of natural populations to environmental change, opening the perspective that evolutionary trait change may subsequently impact ecological processes such as population dynamics, community composition, and ecosystem functioning. To study such eco-evolutionary feedbacks in natural populations, however, requires samples across time. Here, we capitalize on a resurrection ecology study that documented rapid and adaptive evolution in a natural population of the water flea Daphnia magna in response to strong changes in predation pressure by fish, and carry out a follow-up mesocosm experiment to test whether the observed genetic changes influence population dynamics and top-down control of phytoplankton...
January 2018: Evolutionary Applications
David R L Burge, Mark B Edlund, Dagmar Frisch
Paleolimnologists have utilized lake sediment records to understand historical lake and landscape development, timing and magnitude of environmental change at lake, watershed, regional and global scales, and as historical datasets to target watershed and lake management. Resurrection ecologists have long recognized lake sediments as sources of viable propagules ("seed or egg banks") with which to explore questions of community ecology, ecological response, and evolutionary ecology. Most researchers consider Daphnia as the primary model organism in these efforts, but many other aquatic biota, from viruses to macrophytes, similarly produce viable propagules that are incorporated in the sediment record but have been underutilized in resurrection ecology...
January 2018: Evolutionary Applications
Frida Ben-Ami
Parasite virulence is a leading theme in evolutionary biology. Modeling the course of virulence evolution holds the promise of providing practical insights into the management of infectious diseases and the implementation of vaccination strategies. A key element of virulence modeling is a tradeoff between parasite transmission rate and host lifespan. This assumption is crucial for predicting the level of optimal virulence. Here, I test this assumption using the water flea Daphnia magna and its castrating and obligate-killing bacterium Pasteuria ramosa...
December 2017: Ecology and Evolution
Øystein Nordeide Kielland, Claus Bech, Sigurd Einum
Diversified bet-hedging (DBH) by production of within-genotype phenotypic variance may evolve to maximize fitness in stochastic environments. Bet-hedging is generally associated with parental effects, but phenotypic variation may also develop throughout life via developmental instability (DI). This opens for the possibility of a within-generation mechanism creating DBH during the lifetime of individuals. If so, DI could in fact be a plastic trait itself; if a fluctuating environment indicates uncertainty about future conditions, sensing such fluctuations could trigger DI as a DBH response...
December 2017: Ecology and Evolution
Haruna Watanabe, Shigeto Oda, Ryoko Abe, Yoshinari Tanaka, Norihisa Tatarazako
Short-term pulsed exposure tests have been increasingly used to evaluate the ecotoxicity of pollutants of which concentrations vary over time in the field. In pulsed exposure, time-weighted average (TWA) concentration is often used as an index of exposure. However, there have been few studies to demonstrate whether TWA concentration can be used to evaluate the effect of endocrine-disrupting chemicals on the daphnids. Pyriproxyfen is one of the juvenile hormone analogs that induces daphnids to produce male offspring...
December 22, 2017: Chemosphere
Stephen A Y Gipson, Matthew D Hall
The patterns of immunity conferred by host sex or age represent two sources of host heterogeneity that can potentially shape the evolutionary trajectory of disease. With each host sex or age encountered, a pathogen's optimal exploitative strategy may change, leading to considerable variation in expression of pathogen transmission and virulence. To date, these host characteristics have been studied in the context of host fitness alone, overlooking the effects of host sex and age on the fundamental virulence-transmission trade-off faced by pathogens...
December 29, 2017: Journal of Evolutionary Biology
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