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Neocaridina denticulate sinensis is a promising crustacean model species due to its merits in raising and breeding. However, its molecular responses to copper remains largely unknown. In the present research, RNA-seq was used to mine the alteration in transcriptome of N. denticulate sinensis hepatopancreas under copper exposure. A total of 16,423 DEGs was identified between control and Cu 2+ treatment groups. GO enrichment analysis of all DEGs suggested down-regulated genes exceeded up-regulated genes in all the significantly enriched terms, except for RNA polymerase III complex (GO:0005666). KEGG analysis showed Cu exposure only induced two significantly enriched pathways, including Phagosome (ko04145) and Pathogenic Escherichia coli infection (ko05130). Besides, pattern recognition receptors as Toll, lectin B, CTL1 and SRB, AMPs as crustin type I, lysozyme, and NOS were down-regulated after Cu 2+ exposure, while hemocyanin, MT, HSP70 and HSP90 were significantly up-regulated, implying these molecules may play vital role in Cu 2+ detoxification of N. denticulate sinensis. Our results here provide research direction of heavy metal detoxification of N. denticulate sinensis, simultaneously enriched its genomic information., (Copyright © 2021. Published by Elsevier Ltd.)

Neocaridina denticulate sinensis is a small freshwater economic shrimp, as well as excellent laboratory model for their short life cycle and easy availability. However, the response of N. denticulate sinensis to pervasive copper pollution in aquatic environments has not been deeply investigated yet. Herein, we preformed Illumina sequencing technology to mine the alterations of cephalothorax transcriptome under 2.5 μmol/L of Cu 2+ after 48 h. 122,512 unigenes were assembled and 219 unigenes were identified as significantly differentially expressed genes (DEGs) between control and Cu 2+ treatment groups. Functional enrichment analysis revealed that DEGs were mostly associated with immune responses and molting, such as endocytosis, Fc gamma R-mediated phagocytosis and chitin metabolic process. Seven genes were chosen for qPCR verification, and the results showed that the transcriptome sequencing data were consistent with the qPCR results. This is the first report of transcriptome information about N. denticulate sinensis. These results provided a direction for the future research of resistance to Cu 2+ in this shrimp, and simultaneously enriched gene information of N. denticulate sinensis., (Copyright © 2020. Published by Elsevier B.V.)

The objective of this study was to investigate 13 phthalic acid esters (PAEs) with medium or long straight-alkyl-chain, branching or unsaturated side chains, because their structural characteristics make them difficult to biodegrade or highly toxic. A biodegradability and biotoxicity multi-effect pharmacophore model was built using comprehensive evaluation method. The results suggested that introducing hydrophobic groups to the side chains of the PAEs could improve the molecules' biodegradability and biotoxicity effects simultaneously. Thus, 40 target PAE (HEHP, DNOP, DUP) derivatives were designed. Two environmentally friendly PAE derivatives (HEHP-Anthryl and HEHP-Naphthyl) were screened via the test of environmental friendliness and functionality. In addition, the biodegradation and biotoxicity of derivatives were found to have improved as a result of the change in van der Waals forces between molecules and their corresponding proteins. Moreover, the environmental safety of the screened PAE derivatives was confirmed by predicting the toxicity of their intermediates and calculating the energy barrier values for biodegradation and metabolic pathways. This study could provide theoretical guidance for the practical development of environmentally friendly plasticizer.

Natural dissolved organic matter (DOM) forms the base of aquatic food webs and is a key environmental factor that affects the bioavailability of metals for aquatic organisms. Aquatic communities are naturally exposed simultaneously to environments containing a mixture of metals and varying DOM levels and compositions. However, the exact effect of DOM on metal bioaccumulation is difficult to predict due to temporal and spatial variations in sources, production, and consumption of DOM, and to interactions between DOM and metals. Ecosystem metabolism describes the process of organic carbon production and consumption and, therefore, the trophic status of ecosystems. However, whether and how ecosystem metabolism determines the seasonality of metal bioaccumulation remains unclear. The present study used in-situ water quality sondes and discrete field samplings to establish the relationship between the seasonality of ecosystem metabolism; related environmental and limnological regulators; the metal speciation and concentration in bulk water and sediments; and their metal bioaccumulation. The target population consisted of atyid shrimp (Neocaridina denticulata) in a brackish constructed wetland in tropical Taiwan was sampled between August 2014 and November 2015. Metal bioaccumulation displayed distinct seasonal patterns that peaked in summer (Cu, Cd, Cr, Zn, Mn, and Se) or winter (Pb and Ni). The in situ production (gross primary production) and heterotrophic consumption (ecosystem respiration) of organic matter significantly decreased with increasing waterborne DOM levels in this heterotrophic wetland. Both dissolved free metals bioavailable for respiratory surfaces (As, Zn, Cu, and Cr) and insoluble metals available for dietary intake (Mn and Ni) decreased with increasing DOM, as well as with decreasing gross primary production and ecosystem respiration. Seasonal variations of metal bioaccumulation also paralleled the transition in wetland trophic status, which reflected the effect of potential qualitative changes in the wetland DOM pool. Bioaccumulation of most metals displayed strong correlations with gross primary production, ecosystem respiration, and wetland trophic status. Our findings demonstrated that ecosystem metabolism can play a key mediating role in the seasonality of metal bioaccumulation in atyid shrimp, as it links the variation and interaction between DOM level/source, the speciation/bioavailability, and the uptake efficiency for metals by aquatic organisms. This study contributes to the temporal-specific risk assessment of aquatic metal exposure in regional environmental settings. It also reveals ecosystem-specific spectra in the context of changes in climate and environment., Competing Interests: Declaration of Competing Interest The authors declare no competing financial interests., (Copyright © 2020 Elsevier B.V. All rights reserved.)

In vivo nuclear magnetic resonance (NMR) is a powerful analytical tool for probing complex biological processes inside living organisms. However, due to magnetic susceptibility broadening, which produces broad lines in one-dimensional NMR, 1 H- 13 C two-dimensional (2D) NMR is required for metabolite monitoring in vivo . As each 2D experiment is time-consuming, often hours, this limits the temporal resolution over which in vivo processes can be monitored. Furthermore, to understand concentration-dependent responses, studies are traditionally repeated using different contaminant and toxin concentrations, which can make studies prohibitively long (potentially months). In this study, time-resolved non-uniform sampling NMR is performed in the presence of a contaminant concentration sweep. The result is that the lowest concentration that elicits a metabolic response can be rapidly detected, while the metabolic pathways impacted provide information about the toxic mode of action of the toxin. The lowest concentration of bisphenol A (BPA) that induces a response was ∼0.1 mg/L (detected in just 16 min), while changes in different metabolites suggest a complex multipathway response that leads to protein degradation at higher BPA concentrations. This proof of concept shows it is possible, on the basis of "real-time" organism responses, to identify the sublethal concentration at which a toxin impacts an organism and thus represents an essential analytical tool for the next generation of toxicity-based research and monitoring.

Background: Endophytic fungi are largely underexplored in the discovery of natural bioactive products though being rich sources of novel compounds with promising pharmaceutical potential. In this study, Taxus wallichiana, which has huge medicinal value, was investigated for its endophytic diversity and capability to produce bioactive secondary metabolites by analyzing antioxidant, antimicrobial and cytotoxic properties. Methods: The endophytes were identified by ITS-PCR using genomic DNA samples. The secondary metabolites were extracted by solvent extraction method using ethyl acetate. The antioxidant activity was analyzed by Thin Layer Chromatography, Total Phenol Content (TPC), Total Flavonoid Content (TFC) and DPPH assay, and the antimicrobial activity was analyzed by agar-well diffusion method. Brine shrimp lethality assay was used to analyze the cytotoxicity of the fungal extracts. Results: Out of 16 different Taxus trees sampled from different locations of Dhorpatan, 13 distinctive endophytic fungi were isolated and grouped into 9 different genera: Bjerkandera, Trichoderma, Preussia, Botrytis, Arthrinium, Alternaria, Cladosporium, Sporormiella and Daldinia . The ethyl acetate extracts isolated from three endophytic fungi: Alternaria alternata , Cladosporium cladosporioides and Alternaria brassicae showed significant TPC values of 204±6.144, 312.3±2.147 and 152.7±4.958µg GAE/mg of dry extract, respectively, and TFC values of 177.9±2.911, 644.1±4.202 and 96.38±3.851µg RE/mg of dry extract, respectively. Furthermore, these three extracts showed a dose dependent radical scavenging activity with IC 50 concentration of 22.85, 22.15 and 23.001 µg/ml, respectively. The extracts of C. cladosporioides and A. brassicae also showed promising antimicrobial activity against Escherichia coli , Staphylococcus aureus and Bacillus subtilis with a minimum inhibitory concentration of 250μg/ml for all bacteria. Both the samples showed cytotoxic property against shrimp nauplii with LC 50 of 104.2 and 125.9µg/ml, respectively. Conclusions: The crude fungal extracts obtained from endophytes: A. alternata , C. cladosporioides and A. brassicae upon purification and further identification of the bioactive compounds can be a fascinating source for novel pharmaceutical agents., Competing Interests: No competing interests were disclosed., (Copyright: © 2020 Gauchan DP et al.)

Background: Endophytic fungi are largely underexplored in the discovery of natural bioactive products though being rich sources of novel compounds with promising pharmaceutical potential. In this study, Taxus wallichiana, which has huge medicinal value, was investigated for its endophytic diversity and capability to produce bioactive secondary metabolites by analyzing antioxidant, antimicrobial and cytotoxic properties. Methods: The endophytes were identified by ITS-PCR using genomic DNA samples. The secondary metabolites were extracted by solvent extraction method using ethyl acetate. The antioxidant activity was analyzed by Thin Layer Chromatography, Total Phenol Content (TPC), Total Flavonoid Content (TFC) and DPPH assay, and the antimicrobial activity was analyzed by agar-well diffusion method. Brine shrimp lethality assay was used to analyze the cytotoxicity of the fungal extracts. Results: Out of 16 different Taxus trees sampled from different locations of Dhorpatan, 13 distinctive endophytic fungi were isolated and grouped into 9 different genera: Bjerkandera, Trichoderma, Preussia, Botrytis, Arthrinium, Alternaria, Cladosporium, Sporormiella and Daldinia . The ethyl acetate extracts isolated from three endophytic fungi: Alternaria alternata , Cladosporium cladosporioides and Alternaria brassicae showed significant TPC values of 204±6.144, 312.3±2.147 and 152.7±4.958µg GAE/mg of dry extract, respectively, and TFC values of 177.9±2.911, 644.1±4.202 and 96.38±3.851µg RE/mg of dry extract, respectively. Furthermore, these three extracts showed a dose dependent radical scavenging activity with IC 50 concentration of 22.85, 22.15 and 23.001 µg/ml, respectively. The extracts of C. cladosporioides and A. brassicae also showed promising antimicrobial activity against Escherichia coli , Staphylococcus aureus and Bacillus subtilis with a minimum inhibitory concentration of 250μg/ml for all bacteria. Both the samples showed cytotoxic property against shrimp nauplii with LC 50 of 104.2 and 125.9µg/ml, respectively. Conclusions: The crude fungal extracts obtained from endophytes: A. alternata , C. cladosporioides and A. brassicae upon purification and further identification of the bioactive compounds can be a fascinating source for novel pharmaceutical agents., Competing Interests: No competing interests were disclosed., (Copyright: © 2020 Gauchan DP et al.)

The Early Mortality Syndrome (EMS) caused by Vibrio parahaemolyticus has recently resulted in a serious loss in shrimp farms in the Mekong delta, Vietnam. Here, antibacterial activity of copper nanoparticles-chitosan composite (CuCS) against V. parahaemolyticus was investigated. Copper nanoparticles were synthesized using L-ascorbic acid as a green reducing agent and chitosan as a biopolymer matrix and stabilizing agent. The physical properties of CuCS were evaluated. Next, antibacterial activity of 2.5, 5.0, 10.0 ppm CuCS against V. parahaemolyticus inoculated in a sterilized shrimp-pond water was examined. CuCS at 2.5 ppm eliminated 91.47% and 95.26% of V. parahaemolyticus after 2 and 4 h of exposure, respectively. Complete elimination was attained following 2 h of 5.0 ppm CuCS exposure. A complete elimination of V. parahaemolyticus in a real EMS-infected shrimp-pond water was also described. This study is the first to report the antibacterial activity of CuCS against V. parahaemolyticus, an important pathogen in shrimp industry in the Mekong delta, Vietnam.

Over the past several years, in silico analyses of arthropod genomes/transcriptomes have led to the identification of several previously unknown peptide families. The CNMamides are one such peptide group, having been discovered via computational analyses of the fruit fly, Drosophila melanogaster, genome; both a CNMamide precursor and receptor were identified. Recently, a CNMamide family member, VMCHFKICNLamide (disulfide bridging between the cysteine residues), was predicted via in silico mining of a crayfish, Procambarus clarkii, transcriptome, suggesting the presence of this peptide group in members of the Decapoda. Here, using publically accessible transcriptomic data, the phylogenetic/structural conservation, tissue localization, and possible functions of the CNMamide family in decapods were explored. Evidence for CNMamide precursors was found for members of each decapod infraorder for which significant sequence data are available, suggesting a ubiquitous conservation of the CNMamide family in the Decapoda. For the Penaeoidea, Caridea, Astacidea and Achelata, the isoform of CNMamide originally identified from P. clarkii appears to be ubiquitously conserved; in members of the Brachyura, VMCHFKICNMamide (disulfide bridging between the cysteine residues) is the native isoform. Interestingly, the decapod CNMamide gene appears to also have a splice variant in which the carboxy-terminal portion of the preprohormone containing the CNMamide peptide is replaced by one containing a different disulfide bridged peptide that is structurally unrelated to it; this second peptide shows considerable conservation within, but variation among, decapod infraorders. A highly conserved putative CNMamide receptor was identified from members of the Penaeoidea, Astacidea and Brachyura. Phylogenetic analyses support the annotation of the decapod receptor as a true member of the CNMamide receptor family. The presence of precursor and receptor transcripts in both nervous system- and reproductive tissue-specific transcriptomes suggests CNMamides serve as modulators of decapod neural and reproductive control systems., (Copyright © 2019 Elsevier Inc. All rights reserved.)

In contaminated aquatic ecosystems, it is expected that organisms suffer some effects caused by the contaminants. However, for mobile organisms inhabiting heterogeneously contaminated ecosystems, the continuous exposure to contaminants can be avoided by moving to less contaminated habitats. The present study evaluated the habitat selection of the freshwater shrimp Atyaephyra desmarestii experimentally exposed to different copper concentrations to verify whether the heterogeneous contamination distribution and the connectivity between habitats with different copper levels could generate a random population distribution similar to metapopulation. The experiments were performed in the HeMHAS (Heterogeneous Multi-Habitat Assay System), a non-forced multi-compartmented exposure system, in which it is possible to simulate the distribution of contaminants in a linear gradient or as patches of contamination. Copper was used to simulate a linear contamination gradient (26 to 105 μg/L Cu) and two patchy scenarios with three contamination levels [reference zone (R: 26 ± 7 μg/L Cu), mixing zone (M: 61 ± 2 μg/L Cu) and disturbed zone (D: 101 ± 12 μg/L Cu)], with two mixing zones or one central mixing zone in a heterogeneous scenario. In the copper gradient scenario, a clear trend of shrimps (59.6 ± 8.0% of the population) moving to the reference zones and an avoidance of 66.7 ± 11.1% of the most contaminated zone were observed. For the patchy scenarios, a random distribution of organisms (34, 36 and 30% for R, M and D zones, respectively) was observed in the scenario with one mixing zone; on the other hand, a slight preference for the reference zones (44.9 ± 4.8%) was evidenced in the scenario with two mixing zones. As shrimps are able to select less contaminated areas, it is highly important to preserve clean zones in heterogeneously contaminated environments, such as the arrangement in meta-ecosystems, as the less- or uncontaminated zones might represent less stressful areas to protect populations against continuous contamination exposure., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Nanoparticles (NPs) transform in the environment which result in alterations to their physicochemical properties. However, the effects of aging on the toxicity of NPs to aquatic organisms remain to be determined. Further the reports that have been published present contradictory results. The aim of this study was to examine the stability of differently coated silver nanoparticles (AgNPs) in media and the influence of aging of these NP on potential toxicity to freshwater shrimp Paratya australiensis . Coating-dependent changes in the stability of AgNP were observed with aging. Curcumin (C) coated AgNPs were stable, while tyrosine (T) coated AgNPs and epigallocatechin gallate (E) coated AgNPs aggregated in the P. australiensis medium. Increased lipid peroxidation and catalase activity was noted in P. australiensis exposed to AgNPs, suggesting oxidative stress was associated with NP exposure. The enhanced oxidative stress initiated by aged C-AgNPs suggests that aging of these NPs produced different toxicological responses. In summary, data suggest that coating-dependent alterations in NPs, together with aging affect both persistence and subsequent toxicity of NPs to freshwater organisms. Thus, the coating-dependent fate and toxicity of AgNPs together with the effect of their aging need to be considered in assessing the environmental risk of AgNPs to aquatic organisms.

Bioassays using the nonforced exposure approach have been shown to be a relevant tool that might complement the traditional ecotoxicological risk assessment. Because the nonforced exposure approach is based on spatial displacement of organisms and the consequent habitat selection processes, the population density might play an important role in the decision to avoid or prefer an ecosystem. Therefore, the aim of the present study was to assess if the avoidance response to contamination, measured in a nonforced exposure system, is density-dependent and how determinant contamination could be for the habitat-selection process in comparison with the population density. The freshwater shrimp Atyaephyra desmarestii was exposed to a copper gradient in a nonforced exposure system formed by 7 interconnected compartments (total volume 600 mL), which contained different copper concentrations. The density treatments used were 3, 5, and 10 organisms per compartment, corresponding to 0.5, 0.8, and 1.7 organisms per 100 mL, respectively. Clearly, the avoidance response to copper was more intense in the population with the lower density: the highest population density showed the lowest avoidance. The concentrations that triggered an avoidance of 50% of the population were 47, 134, and 163 μg L -1 . In summary, it was observed that shrimps were able to detect and avoid potentially toxic copper concentrations but that the avoidance response was affected by population density. Environ Toxicol Chem 2018;37:3095-3101. © 2018 SETAC., (© 2018 SETAC.)

Mud shrimp are considered as among the most influential ecosystem engineers in marine soft bottom environments because of their significant bioturbation activity and their high density. These organisms play a key role on the physical structure of sediments through intense sediment reworking activity and also deeply influence geochemical properties of sediments via frequent bioirrigation events. The influence that mud shrimp have on the environment is related to the magnitude of bioturbation processes and subsequently depends on their physiological condition. In natural environments, several factors act together and influence the well-being of organisms. Among them, the deleterious role of parasites on the physiology and the behavior of their host is well established. Aquatic organisms are also subject to pollutants released by anthropogenic activities. However, the effect of both stressors on the fitness and bioturbation activity of mud shrimp has never been investigated yet. We conducted a 14-day ex-situ experiment to evaluate the influence of trace metal contamination (cadmium Cd) and parasitism infestation on the gene expression (molecular endpoint) and sediment reworking activity (behavioral endpoint) of the mud shrimp Upogebia cf. pusilla. At completion, mud shrimp exhibited substantial Cd bioaccumulation, with parasitized organisms showing a significantly lower contaminant burden than unparasitized specimens. Cadmium contamination induces modifications of gene expression in both unparasitized and parasitized organisms. We report an antagonistic effect of both stressors on gene expression, which cannot be fully explained by a lower Cd bioaccumulation. At the behaviour level, parasitism seems to reduce the sediment reworking activity of mud shrimp, while Cd contamination appears to stimulate this activity. This study highlights that the effects of multiple stressors may be quite different from the effects of each stressor considered individually. It should also motivate for more studies evaluating the influence of multiple stressors on different endpoints encompassing various levels of organization., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Microplastic (MP) ingestion has been reported in a wide variety of organisms, however, its spatial occurrence and effects on wild populations remain quite unknown. The present study targets an economically and ecologically key species in the Mediterranean Sea, the shrimp Aristeus antennatus. 39.2% of the individuals sampled had MP in their stomachs, albeit in areas close to Barcelona city the percentage reached values of 100%. Overall, MP ingestion was confirmed in a wide spatial and depth (630-1870 m) range, pointing out the great dispersion of this pollutant. The benthophagous diet and close relationship with the sea bottom of A. antennatus might enhance MP exposure and ultimately lead to accidental ingestion. Detailed analysis of shrimps' diet revealed that individuals with MP had a higher presence of endobenthic prey. Microplastic fibers are probably retained for long periods due to stomach's morphology, but no negative effects on shrimp's biological condition were observed., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

The toxicity of two organophosphorus insecticides, chlorpyrifos (CPF), malathion (MAL), and one carbamate insecticide, methomyl (METH), to the yabby (Cherax destructor) was assessed by measuring cholinesterase (AChE, BChE), Glutathione S-Transferase (GST) and Na + /K + ATPase activity after 96h of exposure. Yabbies exposed to all three insecticides at 2 and 5µgL -1 exhibited significant AChE, BChE, GST and Na + /K + ATPase inhibition. Based on these enzyme inhibition tests, the toxicity of the three insecticides to C. destructor was CPF > MAL > METH. After 14 days of recovery the yabbies enzymatic activities of AChE, BChE, GST and Na + /K + ATPase was measured. Recovery of The enzyme activity recovery was faster after the exposure to METH than for the yabbies exposed to CPF and MAL. Slow recovery of enzyme activity could affect the physical activities of organisms and produce indirect effects on populations if such crayfish are less able to elude predators or search for food., (Copyright © 2017 Elsevier Inc. All rights reserved.)

Cadmium (Cd) is a toxic trace element enriched in waters through activities such as mining and agriculture. The freshwater shrimp Paratya curvirostris inhabits near-coastal, lowland streams potentially impacted by Cd, but nothing is known regarding its sensitivity to this metal. An acute (96h) median lethal concentration (LC 50 ) of 405µgL -1 was derived for P. curvirostris, placing it among the most tolerant of freshwater shrimp species. Acute (4 d; 0, 50 and 100µgL -1 ) and sub-chronic (10 d; 0, 25 and 50µgL -1 ) exposures then investigated effects of Cd on energy metabolism (respiration rate, excretion rate, O:N ratio). In contrast to effects in previously studied species, Cd induced an increased respiration rate, which when coupled with an unchanged excretion rate, resulted in an increased O:N ratio. These data were explained by an increased reliance on carbohydrate and/or lipid as a metabolic substrate stimulated by increased metabolic costs of toxicant exposure. Similar effects were seen across all time-points, although the lowest effective Cd concentration decreased with increased exposure time. Overall, results suggest that Cd is unlikely to be a significant environmental stressor to P. curvirostris, except in highly contaminated freshwaters, and/or where Cd co-occurs with hypoxia., (Copyright © 2016 Elsevier Inc. All rights reserved.)

Background: The atyid shrimp Paratya australiensis occurs in surface freshwater habitats throughout eastern Australia and has been used to study the ecotoxicology of contaminants such as pesticides and metals. The acidification of surface water that can occur after acid sulfate material in soils and sediments is oxidised and subsequently re-wetted is a serious environmental issue in coastal regions and inland riverine floodplains worldwide. Solubilisation of soil-associated minerals can result in high waterborne concentrations of mineral salts and dissolved metals, which together with low pH represent a potential threat to aquatic ecosystems in affected regions. The aims of the present study were to gain insight into stress responses induced by exposure to acid drainage water (ADW) in P. australiensis by determining changes in the abundance of protein-coding transcripts and to generate a comprehensive transcriptomic resource to facilitate further research into gene regulation or protein structure and function in this species. Adult P. australiensis were exposed for 24 h to undiluted ADW, 50 % ADW diluted in river water, or to river water as control, and high-throughput mRNA sequencing (RNA-Seq) conducted on whole-body tissues. A reference transcriptome was generated using de novo assembly and putative protein-coding regions were identified and annotated. Changes in transcript abundance in response to ADW exposure were determined by aligning reads to the reference transcriptome and quantifying coverage., Results: A high proportion of arthropod benchmarking universal single-copy orthologues were present in the reference transcriptome. Functions associated with cuticle biosynthesis and oxidative stress were significantly enriched in the lists of transcripts exhibiting differential abundance in either direction after exposure to 50 % or 100 % ADW. Transcripts involved in osmoregulation exhibited decreased abundance following exposure to ADW. The transcriptome contained full-length coding sequences for numerous proteins known to be involved in environmental response pathways, including two putative metallothioneins, four glutathione peroxidases and 19 nuclear receptors., Conclusions: The results of the present study provide insight into stress response pathways induced in crustaceans by short-term exposure to multiple stressors present in ADW such as low pH, high salinity and dissolved metals, and represent a resource for future toxicogenomics and protein functional studies in P. australiensis.

Norfloxacin chitosan/chitosan oligosaccharide microcapsules (NCCM) were prepared by emulsion-chemical crosslinking method. The characteristics of obtained microcapsules were evaluated by scanning electron microscopy, Fourier transform infrared spectroscopy and release experiments. Cumulative release profile of norfloxacin from the chitosan microcapsules in natural seawater was measured and the controlled release of drugs was at a uniform rate in 48h. The chitosan microcapsules were applied onto the antibacterial study of the shrimp culture in natural seawater. It is observed that the seawater in the NCCM added groups was relatively clear and the biomass of Vibrio increased slowly in contrast to the control and norfloxacin groups. The inhibition rate of Vibrio in norfloxacin groups obvioursly decreased after the 5 th day, whereas, it remained high and stable during experiment period in NCCM groups. The results showed that the chitosan microcapsules as release materials have excellent antibacterial effects on Vibrio in the farming of Penaeus vannamei Boone. The controlled release could obviously reduce dosage of antibiotics and delivery times, and effectively improve the utilization rate of norfloxacin drugs for shrimps., (Copyright © 2016 Elsevier B.V. All rights reserved.)

Lethal and sublethal responses of the shrimp Atyaephyra desmarestii exposed to three pharmaceutical compounds, Diclofenac (DF), Ibuprofen (IB) and Carbamazepine (CBZ), individually and in mixtures, were evaluated under two temperature scenarios. LC50 (96h) values were obtained individually at 20° and 25°C. At 25°C, mortality in binary and ternary mixtures is higher than at 20°C. The toxicity of the mixtures was predicted on the basis of individual mortality data using two toxicity models: Concentration addition (CA) and Independent action (IA). Our results showed that neither CA nor IA unequivocally predicted the observed toxicity of binary and ternary mixtures. For sublethal toxicity, selected endpoints were: ingestion rate, osmoregulatory capacity and respiration rate. Regarding osmoregulatory capacity, no significant differences were found. The highest ingestion rates were recorded in organisms exposed at 25°C, irrespective of the compound, after 30 and 60min of exposure. At 20°C, there was a significant decrease in respiration rate (Dunnett́s test p<0.05) under conditions of severe anoxia (1mg O2L(-1)) in organisms exposed to 13.3μgL(-1) of DF. At 25°C a significantly lower respiration rate with respect to the control (Dunnett́s test p<0.05) was found in organisms exposed to 13.8μgL(-1) of CBZ under conditions of moderate hypoxia and well-oxygenated water (3 and 5mg O2L(-1), respectively). The respiratory independence of organisms exposed to the higher temperature (25°C) also decreased. This study shows that CBZ and DF individually, even at relatively low concentrations, may produce respiratory deficiencies in the freshwater shrimp, Atyaephyra desmarestii under certain temperature and water oxygenation conditions, thus reducing its ability to function., (Copyright © 2016 Elsevier B.V. All rights reserved.)

Freshwater ecosystems are essential for humans; however, input of several types of contamination has led to the degradation of these ecosystems. Thus, it is urgent to assess their health to allow actions for prevention and remediation. The level of trace metals can be enhanced by natural or anthropogenic sources. Essential metals, such as copper and zinc, become toxic when present in the environment above threshold concentrations. To evaluate the physiological effects of these 2 essential metals for 2 freshwater detritivores, the shrimp Atyaephyra desmarestii and the amphipod Echinogammarus meridionalis, acute tests were performed. Forty-eight hour median lethal concentration (LC50) values were estimated for these species using static bioassays with copper and zinc. Sublethal assays for both metals with several phases were also done to evaluate the effects on feeding behavior. The LC50 values of copper for the shrimp A. desmarestii and amphipod E. meridionalis were 0.128 mg/L and 0.050 mg/L and those of zinc were 7.951 mg/L and 11.860 mg/L, respectively. The results indicated that copper is more toxic to both species. Only E. meridionalis showed deleterious effects of copper on feeding rate. Zinc showed some tendency for feeding inhibition in both species. Environ Toxicol Chem 2016;35:1442-1448. © 2015 SETAC., (© 2015 SETAC.)

In light of deep-sea mining industry development, particularly interested in massive-sulphide deposits enriched in metals with high commercial value, efforts are increasing to better understand potential environmental impacts to local fauna. The aim of this study was to assess the natural background levels of biomarkers in the hydrothermal vent shrimp Rimicaris exoculata and their responses to copper exposure at in situ pressure (30MPa) as well as the effects of depressurization and pressurization of the high-pressure aquarium IPOCAMP. R. exoculata were collected from the chimney walls of the hydrothermal vent site TAG (Mid Atlantic Ridge) at 3630m depth during the BICOSE cruise in 2014. Tissue metal accumulation was quantified in different tissues (gills, hepatopancreas and muscle) and a battery of biomarkers was measured: metal exposure (metallothioneins), oxidative stress (catalase, superoxide dismutase, glutathione-S-transferase and glutathione peroxidase) and oxidative damage (lipid peroxidation). Data show a higher concentration of Cu in the hepatopancreas and a slight increase in the gills after incubations (for both exposed groups). Significant induction of metallothioneins was observed in the gills of shrimps exposed to 4μM of Cu compared to the control group. Moreover, activities of enzymes were detected for the in situ group, showing a background protection against metal toxicity. Results suggest that the proposed method, including a physiologically critical step of pressurizing and depressurizing the test chamber to enable the seawater exchange during exposure to contaminants, is not affecting metal accumulation and biomarkers response and may prove a useful method to assess toxicity of contaminants in deep-sea species., (Copyright © 2016. Published by Elsevier B.V.)

Pharmaceuticals and personal care products (PPCPs) form part of the new generation of pollutants present in many freshwater and marine ecosystems. Although environmental concentrations of these bioactive substances are low, they cause sublethal effects (e.g., enzyme inhibition) in non-target organisms. However, little is known on metabolism of PPCPs by non-mammal species. Herein, an in vitro enzyme trial was performed to explore sensitivity of carboxylesterase (CE) activity of aquatic organisms to fourteen PPCPs. The esterase activity was determined in the liver of Mediterranean freshwater fish (Barbus meridionalis and Squalius laietanus), coastal marine fish (Dicentrarchus labrax and Solea solea), middle-slope fish (Trachyrhynchus scabrus), deep-sea fish (Alepocephalus rostratus and Cataetix laticeps), and in the digestive gland of a decapod crustacean (Aristeus antennatus). Results showed that 100μM of the lipid regulators simvastatin and fenofibrate significantly inhibited (30-80% of controls) the CE activity of all target species. Among the personal care products, nonylphenol and triclosan were strong esterase inhibitors in most species (36-68% of controls). Comparison with literature data suggests that fish CE activity is as sensitive to inhibition by some PPCPs as that of mammals, although their basal activity levels are lower than in mammals. Pending further studies on the interaction between PPCPs and CE activity, we postulate that this enzyme may act as a molecular sink for certain PPCPs in a comparable way than that described for the organophosphorus pesticides., (Copyright © 2015 Elsevier B.V. All rights reserved.)

Objective: To understand the impact of niclosamide ethanolamine salt on the Yangtze River wetland creatures, so as to provide an evidence for the environmental impact assessment of the Oncomelania hupensis control measures., Methods: Eriocheir sinensis, Procambarus clarkii, freshwater mysis and Bellamya aeruginosa were chosen as the test organisms from the lower reaches of the Yangtze River in Nanjing City, and they were immersed in the different concentrations of niclosamide ethanolamine salt solution for 24-96 h. The mortality rates and LC50 values were calculated., Results: There was only 1 death (with a mortality rate of 8.33%) of P. clarkia immersed in niclosamide ethanolamine salt with the concentration of 400 mg/L for 96 h. There was no death of the E. sinensis immersed in niclosamide ethanolamine salt with the concentration of 640 mg/L for 96 h. The LC50 values were 2.170 4, 1.303 6, 1.013 1 mg/L and 0.720 5 mg/L respectively when the freshwater mysis were immersed in the solution for 24, 48, 72 h and 96 h. The LC50 values were 1.173 5, 0.642 1, 0.477 3 mg/L respectively when the B. aeruginosa were immersed in the solution for 24, 48, 72, 96 h., Conclusions: The impacts of niclosamide ethanolamine salt on the different wetland creatures are different. E. sinensis and P. clarkii have high resistance to niclosamide ethanolamine salt. However, niclosamide ethanolamine salt shows heavy toxicity on the freshwater mysis and Bellamya aeruginosa.

The input of metals into freshwater ecosystems from natural and anthropogenic sources impairs water quality and can lead to biological alterations in organisms and plants, compromising the structure and the function of these ecosystems. Biochemical biomarkers may provide early detection of exposure to contaminants and indicate potential effects at higher levels of biological organisation. The effects of 48h exposures to copper and zinc on Atyaephyra desmarestii and Echinogammarus meridionalis were evaluated with a battery of biomarkers of oxidative stress and the determination of ingestion rates. The results showed different responses of biomarkers between species and each metal. Copper inhibited the enzymatic defence system of both species without signs of oxidative damage. Zinc induced the defence system in E. meriodionalis with no evidence of oxidative damage. However, in A. desmarestii exposed to zinc was observed oxidative damage. In addition, only zinc had significantly reduced the ingestion rate and just for E. meridionalis. The value of the integrated biomarkers response increased with concentration of both metals, which indicates that might be a valuable tool to interpretation of data as a whole, as different parameters have different weight according to type of exposure., (Copyright © 2015 Elsevier Inc. All rights reserved.)

Cadmium, one of the most toxic heavy metals in aquatic environments, has severe effects on marine invertebrates and fishes. The MAPK signaling pathway plays a vital role in stress responses of animals. The mitogen-activated protein kinase (MAPK) signaling pathway plays a vital role in animals' stress responses, including mediation of apoptosis induced by the Rho GTPase Cdc42. However, there is limited knowledge about its function in shrimps, although disorders exacerbated by environmental stresses (including heavy metal pollution) have caused serious mortality in commercially cultured shrimps. Thus, we probed roles of Cdc42 in Litopenaeus vannamei shrimps (LvCdc42) during cadmium exposure by inhibiting its expression using dsRNA-mediated RNA interference. The treatment successfully reduced expression levels of MAPKs (including p38, JNK, and ERK). Cadmium exposure induced significant increases in expression levels of LvCdc42 and MAPKs, accompanied by reductions in total hemocyte counts (THC) and increases in apoptotic hemocyte ratios and ROS production. However, all of these responses were much weaker in LvCdc42-suppressed shrimps, in which mortality rates were higher than in controls. Our results suggest that the MAPK pathway plays a vital role in shrimps' responses to Cd(2+). They also indicate that LvCdc42 in shrimps participates in its regulation, and thus plays key roles in ROS production, regulation of apoptosis and associated stress responses., (Copyright © 2015 Elsevier B.V. All rights reserved.)

In order to study the physiological response to heavy metals and organic-phosphorus pesticide toxicity of aquatic organisms, Neocaridina denticulate was used as a test organism to investigate the impact of physiological indices of N. denticulate muscle tissues when they were exposed to Cu2+ and chlorpyrifos for 5 days respectively with the test methods of semi-static toxicity. The results showed that: when exposed to different concentrations of Cu2+ and chlorpyrifos solutions, the protein concentrations in muscle tissues were significantly lower with the extension of time to varying degrees. In the lower concentration groups of Cu2+ (0.086 mg x L(-1) and 0.172 mg-L-') and the higher concentration groups of chlorpyrifos (0. 006 0 [g-L-' and 0.012 0 μg x L(-1)), the total SOD activity showed inhibitory effect; the trend of the higher concentration group of Cu2+ (0.344 mg x L(-1) and 0.688 mg x L(-1)) showed " inhibition-promotion-inhibition", however, the lower concentration groups of chlorpyrifos (0.001 5 μg x L(-1) and 0.003 0 μg x L(-1)) showed the" inhibition-promotion" changes in trends; MDA contents changed similarly, and within a certain range of concentrations, MDA contents presented a gradually rising trend with increasing Cu2+ and chlorpyrifos concentration, which indicated that Cu2+ and chlorpyrifos accelerated lipid, peroxidation in muscle tissues of N. denticulate. In addition, AChE activity in Cu2+ and chlorpyrifos solutions showed inhibitory effect, and in the solutions with higher concentration of Cu2+ and chlorpyrifos, the activity was gradually decreased with the increase of concentration, indicating that Cu2+ and chlorpyrifoscs impacted the normal physiological functions of N. denticulate, and the higher the concentration, the greater the damage effect. Based on the analysis results, we confirmed that the total SOD, MDA and AChE played significant roles as physiological indicators in evaluating toxic effect of heavy metals and organic-phosphorus pesticide on N. denticulate.

Bioindicators can reflect the effects of pollutants on their metabolism, being widely used to assess environmental stress. In this sense, the crab Procambarus clarkii has been previously proposed to monitor the contamination in Doñana National Park (southwest Spain) using conventional biomarkers. In this work, a metabolomic approach based on direct infusion mass spectrometry, which allows an easy and quick study of a large number of metabolites in a single run, was used for pollution assessment of this area, considering the biological response of this organism to contamination. In addition, metal accumulation in crab tissues was determined. Thus, the integrated analysis of metabolomic and metallomic data enabled the study of metabolic response of the organism against pollution. Several metabolites were discovered as potential biomarkers of pollution, such as decreased levels of carnosine, alanine, niacinamide, acetoacetate, pantothenic acid, ascorbate, glucose-6-phosphate, arginine, glucose, lactate, phospholipids, and tryglicerides, as well as elevated levels of acetyl carnitine, phosphocholine, choline, and uric acid. In this way, metal-induced toxicity could be related to metabolic impairments, principally oxidative stress, metabolic dysfunction, and dyslipidemia.

Methods that quantify dissolved hydrocarbons are needed to link oil exposures to toxicity. Solid phase microextraction (SPME) fibers can serve this purpose. If fibers are equilibrated with oiled water, dissolved hydrocarbons partition to and are concentrated on the fiber. The absorbed concentration (Cpolymer) can be quantified by thermal desorption using GC/FID. Further, given that the site of toxic action is hypothesized as biota lipid and partitioning of hydrocarbons to lipid and fibers is well correlated, Cpolymer is hypothesized to be a surrogate for toxicity prediction. To test this method, toxicity data for physically and chemically dispersed oils were generated for shrimp, Americamysis bahia, and compared to test exposures characterized by Cpolymer. Results indicated that Cpolymer reliably predicted toxicity across oils and dispersions. To illustrate field application, SPME results are reported for oil spills at the Ohmsett facility. SPME fibers provide a practical tool to improve characterization of oil exposures and predict effects in future lab and field studies., (Copyright © 2014 Elsevier Ltd. All rights reserved.)

Aquatic organisms use chemical cues to perform key ecological behaviours such as locating food. Anthropogenic pollutants have the potential to disrupt these behaviours by down-regulating chemoreception. Urban stormwater runoff is a major source of metal pollution, particularly Zn, and is a leading contributor to the degradation of receiving waters. Consequently, significant remedial efforts have focused on using constructed stormwater wetlands to reduce pollutant loads. However, no studies have examined the efficacy of water quality improvements on ecologically relevant behaviours in aquatic biota. We conducted controlled laboratory experiments to test whether untreated (100 and 400 µg L(-1)) and treated (40 µg L(-1)) stormwater Zn concentrations observed in constructed wetlands interfere with the foraging behaviour of the glass shrimp (Paratya australiensis). The ability of shrimp to perceive, approach and search for a chemoattractant source was used to assess foraging behaviour. Abnormal foraging behaviour was observed in shrimp exposed to Zn at untreated stormwater concentrations. The strongest change relative to the control was observed for perception, which decreased by more than 80 and 60 % in the 400 µg Zn L(-1) and 100 µg Zn L(-1) groups, respectively. The behaviour of shrimp exposed to Zn concentrations measured in treated stormwater did not differ from the controls. The results suggest that the reduction of stormwater Zn concentrations via wetland treatment can prevent abnormal contamination-induced behaviours in shrimp, leading to improved aquatic ecosystem health. This study also highlights the subtle, but biologically significant impacts arising from sublethal exposures of Zn, and emphasise the utility of behavioural toxicology. The behavioural test used here is a simple and effective approach that could be incorporated into studies assessing the efficacy of stormwater treatment.

Differences relating to the ability of various types of humic substances (HS) to influence toxicity of pollutants have been reported in the literature, but there still remains a gap in understanding whether various HS will have the same influence on the toxicity of acid mine drainage (AMD). This study investigated differences in the ability of Aldrich humic acid (AHA), Suwannee River humic acid and Suwannee River fulvic acid to decrease toxicity of AMD to the freshwater shrimp (Caridina sp. D). Toxicity tests were conducted over 96 h and used Mount Morgan open pit water as source of AMD and Dee River water as control/diluents. Concentrations of 0-4 % AMD at 0 mg/L HS, 10 mg/L AHA, 10 mg/L Suwannee River humic acid and 10 mg/L Suwannee River fulvic acid were used. Significantly higher survival of shrimp was recorded in the HS treatments compared with the treatment containing no HS. No significant differences were found among HS type. HS considerably increased LC50 values irrespective of type, from 1.29 (0 mg/L HS) to 2.12 % (AHA); 2.19 (Suwannee River humic acid) and 2.22 % (Suwannee River fulvic acid). These results support previous work that HS decrease the toxicity of AMD to freshwater organisms, but with the novel finding that this ability occurs irrespective of HS type. These results increase the stock of knowledge regarding HS and may contribute to a possible remediation option for AMD environments.

In recent years, numerous studies have indicated that various long-term use drugs, such as antibiotics or analgesics, not only cannot be completely decomposed via sewage treatment but also exhibit biological toxicity if they enter the environment; thus, the release of these drugs into the environment can damage ecological systems. This study sought to investigate the acute toxicity of two commonly utilized analgesics, ibuprofen (IBU) and acetaminophen (APAP), to aquatic organisms after these drugs have entered the water. To address this objective, the acute toxicity (median lethal concentration, LC₅₀, for a 96-h exposure) of IBU alone, APAP alone, and mixtures containing different ratios of IBU and APAP in green neon shrimp (Neocaridina denticulata) were measured. The results of four tests revealed that the 96-h LC₅₀ values for IBU and APAP alone were 6.07 mg/L and 6.60 mg/L, respectively. The 96-h LC₅₀ for a 1:1 mixture of IBU and APAP was 6.23 mg/L, and the toxicity of this mixture did not significantly differ from the toxicity of either drug alone (p<0.05). The experimental results for mixtures containing unequal ratios of IBU and APAP indicated that mixtures with high APAP concentrations and low IBU concentrations exhibited markedly greater toxicity in N. denticulata (LC₅₀=4.78 mg/L) than APAP or IBU alone. However, mixtures with high IBU concentrations and low APAP concentrations exhibited lower toxicity in N. denticulata (LC₅₀=6.78 mg/L) than IBU or APAP alone. This study demonstrated that different mixtures of IBU and APAP were associated with different toxic effects in green neon shrimp., (Copyright © 2014 Elsevier B.V. All rights reserved.)

Bicarbonate is often a major ionic constituent associated with produced waters from methane gas extraction and coal mining, yet few studies have determined its specific toxicity. Currently, the environmental risk of bicarbonate anion in water discharges is assessed based on the toxicity of sodium chloride or artificial seawater and is regulated via electrical conductivity. Increased NaHCO(3) added to Ceriodaphnia dubia in synthetic or natural water gave similar 48-h 10% effective concentration (EC10) values of 1750 ± 125 mg NaHCO(3)/L (mean ± standard error) and 1670 ± 180 mg NaHCO(3)/L, respectively. Bicarbonate was toxic to C. dubia in both waters with conductivities above 1900 µS/cm. In contrast, when conductivity was elevated with NaCl, toxicity to C. dubia was observed only above 2800 µS/cm. Bicarbonate also impaired C. dubia reproduction with an EC10 of 340 mg NaHCO(3)/L. Major ion composition also influenced Zn bioavailability, a common co-occurring metal contaminant in coal mine waters, with sublethal concentrations of NaHCO(3) and elevated pH increasing Zn toxicity. Higher pH was the dominant parameter determining a 10-fold increase in the 48-h 50% effective concentration (EC50) for Zn toxicity to C. dubia at pH 8.6 of 34 µg Zn/L (95% confidence limit = 32-37 µg Zn/L) compared with the Zn toxicity at approximately circumneutral pH. Exposure of the freshwater shrimp Paratya australiensis (Atyidae) in natural water to increasing bicarbonate gave a mean 10-d 10% lethal concentration (LC10) of 850 ± 115 mg NaHCO(3)/L, associated with a mean conductivity EC10 of 1145 µS/cm, which is considerably lower than toxicity of NaCl and artificial seawater to this species reported elsewhere. Because toxicity was influenced by salt composition, specific ions should be regulated rather than conductivity alone in mine wastewater discharges., (© 2014 SETAC.)

Individuals are commonly exposed to fluctuating levels of stressors, while most laboratory experiments focus on constant exposures. We develop and test a mathematical model for predicting the effects of low dissolved oxygen (hypoxia) on growth, reproduction, and survival using laboratory experiments on fish and shrimp. The exposure-effects model simulates the hourly reductions in growth and survival, and the reduction in reproduction (fecundity) at times of spawning, of an individual as it is exposed to constant or hourly fluctuating dissolved oxygen (DO) concentrations. The model was applied to seven experiments involving fish and shrimp that included constant and fluctuating DO exposures, with constant exposures used for parameter estimation and the model then used to simulate the growth, reproduction, and survival in the fluctuating treatments. Cumulative effects on growth, reproduction, and survival were predicted well by the model, but the model did not replay the observed episodic low survival days. Further investigation should involve the role of acclimation, possible inclusion of repair effects in reproduction and survival, and the sensitivity of model predictions to the shape of the immediate effects function. Additional testing of the model with other taxa, different patterns of fluctuating exposures, and different stressors is needed to determine the model's generality and robustness., (© 2013 Elsevier Ltd. All rights reserved.)

Single and mixture toxicity tests on three pharmaceutical compounds, Diclofenac (DF), Ibuprofen (IB) and Carbamazepine (CBZ), were carried out with the freshwater shrimp Atyaephyra desmarestii. Lethal and sublethal responses were analyzed for single compounds. Lethal concentrations (LC50) obtained for each individual compound, after 96 h of exposure, were 6.3 mg L(-1) for DF, 13.3 mg L(-1) for IB and 94.3 mg L(-1) for CBZ. The selected sublethal endpoints of food ingestion, osmoregulatory capacity and respiration rates were not affected by the exposures to environmentally-relevant concentrations. Based on mortality data obtained, the predictive no effect concentration (PNEC) was calculated for each of the compounds, and compared with predicted environmental concentrations (PEC) reported in surface waters. The environmental risk of each compound was estimated as the ratio between PEC/PNEC, and indicated that IB could represent a medium risk in freshwater environments. Additionally, binary and ternary mixture toxicity assays of the selected compounds were carried out. The data obtained was applied to two predictive toxicity models: Concentration Addition (CA) and Independent Action (IA). Finally, risk assessment was estimated using risk quotients (RQ) for the compound mixtures based on EC50 and LC50 values., (Copyright © 2013 Elsevier B.V. All rights reserved.)

Cd is one of the most common pollutants in the environment that also induces the apoptosis. To explore the mechanism of apoptosis in the hepatopancreas, freshwater crab S. henanense were treated with 0, 3.56, 7.12, 14.25, 28.49 and 56.98 mg/L Cd for 72 h. Apoptosis was noticeable in every treatment group and necrosis was observed clearly in the high concentration Cd groups. Classical apoptotic bodies were found by transmission electronic microscopy, which revealed chromatin condensation under nuclear membrane and mitochondrial membrane rupture. An increasing number of autolysosomes, damaged rough endoplamic reticulum and Golgi complex were observed as the Cd concentration increase. Brown colored apoptotic cells were detected by the TUNEL test in all Cd-treatment groups. The apoptosis index increased following the elevation of Cd concentration and got 32.9% in the highest Cd group. Caspase-9 and caspase-3 activities increased in the lower Cd treatment groups but no changes in the higher Cd concentration groups (comparing to the control group). The activity of caspase-8 did not change significantly. No significant change in the content of mitochondrial cytochrome c (cyt c) in Cd exposed groups except the decrease in the 56.98 mg/L group. In crabs treated with 3.56, 7.12 and 14.25 mg/L Cd, hyperpolarization of mitochondrial membrane potential (Δψ m ) significantly increased. These results implied that apoptosis in the hepatopancreas induced by Cd occurrs through the mitochondrial caspase-dependent pathway. However, whether there are other apoptotic pathways needs to be studied further.

We studied here the short-term toxicity effects of Cd on the oxidative state and cell death in the gill of freshwater crab Sinopotamon henanense. Crabs were exposed to Cd that resulted in Cd accumulation and a significant increase in the metallothionein (MT) level in the gill, but MT level increased disproportionally compared to the Cd accumulation with an extension of exposure time. Significant changes in the activities of superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx) were observed. An increase in the levels of reactive oxygen species (ROS) and lipid peroxidation (LPO) was detected that will cause oxidative stress. Histological abnormalities of the gills were discovered, including the expansion of gill cavity, a decrease in the numbers of connection of the upper and the lower of the gill lamellae and epithelial cells, and an increase in the number of hemocytes. The results of a TUNEL test and transmission electron microscope (TEM) showed that more gill cells had apoptotic characteristics after 48 h of Cd treatment compared to the control, but epithelial cell necrosis and inflammatory response appeared only after 72 h. It was concluded that (1) Cd induced the ROS production and accumulation through inhibiting antioxidant enzyme activities and exceeding the saturation values of MT binging; (2) Cd led to lipid peroxidation and histopathological alternations; and (3) Cd induced apoptotic response at short time exposure, followed by necrotic features and inflammatory reaction after longer time exposure.

Sucralose (1,6-dichloro-1,6-dideoxy-b-D-fructo-furanosyl 4-chloro-4-deoxy-a-D-galactopyranoside), sold under the trade name Splenda, has been detected in municipal effluents and surface waters in the United States and Europe. The environmental presence of sucralose has led to interest in the possibility of toxic effects in non-target species. This review presents an environmental risk assessment of sucralose based on available data concerning its presence, fate and effects in the environment. Sucralose, which is made by selective chlorination of sucrose, is a highly stable compound, which undergoes negligible metabolism in mammals, including humans, and displays a low biodegradation potential in the environment. This intense sweetener is highly soluble in water, displays a low bioaccumulation potential and a low sorption potential to soil and organic matter, and thus is predominantly present in the water column. The predicted environmental concentration (PEC) for sucralose, based on measured data in surface waters, was determined to be 10 μg/L. Aquatic toxicity studies using standardized, validated protocols used in regulatory decision making indicate that sucralose does not alter survival, growth and reproduction of aquatic organisms (such as plants, algae, crustaceans and fish) at concentrations >9000 times higher than those detected in the environment. Some studies, using non-standardized protocols, have reported behavioral and other non-traditional responses in aquatic organisms, but the relevance of these findings for assessing adverse effects on individuals and populations will require further investigation. In terms of traditional risk assessment, the proposed predicted no effect concentration for aquatic organisms (PNEC) was determined to be 0.93 mg/L, based on the lowest no effect concentration (NOEC) from a validated chronic study with mysid shrimp and an application factor of 100. The resultant PEC/PNEC quotient was determined to be well below 1 (PEC/PNEC=0.08), thus indicating a limited risk to the environment using traditional ecological risk assessment approaches., (Copyright © 2012 Elsevier B.V. All rights reserved.)

Freshwater crayfish Cherax quadricarinatus have a high commercial value and are cultured in farms where they are potentially exposed to pesticides. Therefore, we examined the sublethal effects of a 50-day exposure to glyphosate acid and polyoxyethylenamine (POEA), both alone and in a 3:1 mixture, on the growth and energetic reserves in muscle, hepatopancreas and hemolymph of growing juvenile crayfish. Exposure to two different glyphosate and POEA mixtures caused lower somatic growth and decreased muscle protein levels. These effects, caused by both compounds interacting in the mixture, could also be synergistic because they were expressed even at the lowest concentration. The decrease in protein levels could be related to the greater use of other energy reserves. This hypothesis is supported by the decrease in muscle glycogen stores due to glyphosate exposure and the decrease in lipid reserves associated with exposure to POEA.

This study set out to understand the sublethal effect of xenobiotic phthalate esters (PAEs) on the relationship between the susceptibility of shrimp to bacterial infection and the immune response of the shrimp. Neocaridina denticulate were exposed to different concentrations of the PAE dipropyl phthalate (DPrP), and mortality and six immune parameters were measured on days 1, 3, 5, and 10 after exposure. On days 1 and 3 after exposure, shrimp exposed to 0, 1, 5, 10, and 50 mg/L of DPrP and challenged with Aeromonas veronii experienced 14% and 16%, 16% and 16%, 18% and 18%, 34% and 24%, and 38% and 26% mortality, respectively. On day 1, five immune parameters (acid phosphatase, AcP; β-glucuronidase, β-Glu; phenoloxidase, PO; superoxide dismutase, SOD; and haemocyanin mRNA) were significantly altered in the all of the groups treated with DPrP compared to the untreated shrimp and were elevated in the 10 mg/L- and 50 mg/L-treated groups. Beta-Glu activity and haemocyanin mRNA levels were significantly increased in a dose-dependent manner. These results suggest that the increased susceptibility of N. denticulate exposed to DPrP is short-term and may be related to the increased expression of DPrP-induced immune mediators., (Copyright © 2011 Elsevier Ltd. All rights reserved.)

To assess the toxicity of nonylphenol towards aquatic crustaceans, Neocaridina denticulata were exposed short-term to sublethal concentration (0.001-0.5 mg/L). Following treatment, differentially expressed genes were identified using suppression subtractive hybridization on samples prepared from whole specimens. There were 20 differentially expressed sequence tags that corresponded to known genes and could be divided into six functional classes: defence, translation, metabolism, ribosomal gene expression, respiration, and genes involved in the stress response. Using semi-quantitative RT-PCR, we found that 14 of the differentially expressed sequence tags significantly responded to nonylphenol, including six at a nominal concentration of 0.01 mg/L; among them, 12 genes were down-regulated. These results suggest that under non-lethal concentrations of nonylphenol, the polluted aquatic environment may still present a potential risk to N. denticulata.

The toxicity of carbaryl, chlorpyrifos, dimethoate and profenofos to the freshwater shrimp, Paratya australiensis was assessed by measuring acetylcholinesterase (AChE) inhibition after 96h exposures. Shrimp exposed to these pesticides exhibited significant AChE inhibition, with mortality in shrimp corresponding to 70-90% AChE inhibition. The sensitivity of P. australiensis to the four pesticides based on AChE inhibition can be given as chlorpyrifos > profenofos > carbaryl > dimethoate. Recovery of AChE activity was followed in shrimp after 96 h exposures to carbaryl, chlorpyrifos and dimethoate. Recovery after exposure to the carbamate pesticide carbaryl was more rapid than for the two organophosphorus pesticides, chlorpyrifos and dimethoate. The slow recovery of depressed AChE activity may mean that affected organisms in the natural system are unable to sustain physical activities such as searching for food or eluding predators. To investigate the ecological significance of AChE inhibition, chemotaxis behaviour was assessed in shrimp exposed to profenofos for 24h. Abnormal chemotaxis behaviour in the exposed shrimp was observed at concentrations representing 30-50% AChE inhibition. A clear relationship existed between the depression of AChE activity and observed chemotaxis responses, such as approaching and grasping the chemoattractant source. These results suggest that in vivo toxicity tests based on this specific biomarker are sensitive and present advantages over conventional acute tests based on mortality. Behavioural studies of test organisms conducted in conjunction with measurement of AChE inhibition will provide data to clarify the toxic effects caused by sublethal chemical concentrations of anti-cholinesterase compounds., (Crown Copyright © 2010. Published by Elsevier Inc. All rights reserved.)

Toxicity of six pesticides (carbaryl, chlorpyrifos, cypermethrin, dimethoate, diuron and fenarimol) to the freshwater shrimp, Paratya australiensis was assessed after 96 h exposures. Of the six pesticides tested, alpha cypermethrin was the most toxic to the shrimp followed by chlorpyrifos, carbaryl, dimethoate, fenarimol and diuron. Regression methods for predicting chronic toxicity (lethality) from acute lethality data with shrimp were developed and compared, and it was found that the log-log model gives the most reliable predictions of the probability of death as a function of extended exposure times. Based on this model, chronic toxicity (21 days) to P. australiensis was estimated as 0.0058 microg/L for alpha cypermethrin, 4.9 microg/L for carbaryl, 0.004 microg/L for chlorpyrifos, 89 microg/L for dimethoate, 240 microg/L for diuron and 1500 microg/L for fenarimol. Acute LC(10) values were also useful predictors of the chronic lethality. The log-log model was used to derive extrapolated chronic values that were compared to measured experimental chronic values for two fish species. The predictions of chronic toxicity based on acute toxicity data were found to give credible results for both fish species. These predictions of chronic toxicity can therefore be used in ecological risk assessments to fill in gaps with reasonable confidence where no measured estimates of chronic toxicity are available., ((c) 2009. Published by Elsevier Inc. All rights reserved.)

The effects of dietary Selenium (Se) supplementation on muscle superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPX) activities and haemolymph superoxide anions (O(2)-) of Neocaridina heteropoda exposed to ambient nitrite were investigated. The results showed supplementation of Se in diet could enhance the resistance of shrimp to low concentration ambient nitrite. The results demonstrated that Se might have a potentially useful role as an effective antioxidant and resistance to aqueous nitrite in shrimp and the effect of the organic Se was better than that of the inorganic Se.

Three trials were conducted to determine the effects of mannan oligosaccharide (Bio-Mos ) on the immune responses of marron. In the first trial marron were challenged with Vibrio mimicus infection, in the second with NH3 exposure and in the third, the marron were exposed to air during a simulated live transportation trial. For V. mimicus infection and live transportation trials, marron (10.44 +/- 0.20 g and 4.44 +/- 0.20 g initial weights, respectively) were fed three different diets containing 0% (control diet), 0.2% and 0.4% Bio-Mos for 30 days and 112 days respectively before challenge, whereas for the NH3 exposure trial, marron (94 +/- 2.17 g initial weight) were reared with the control diet and 0.4% Bio-Mos diet for 42 days before exposure to NH3. Marron were examined for survival and total haemocyte count (THC), differential haemocyte count (DHC), haemolymph clotting time, bacteraemia and lysosomal membrane stability as indicators of immune responses during the course of the challenge. Survival of marron infected with bacteria and exposed to NH3, were significantly improved when fed Bio-Mos. THCs were significantly reduced in marron fed the control diet when they were infected with bacteria and subjected to live transportation while it remained unchanged in the marron fed the Bio-Mos supplemented diets. THCs of marron fed any of the diets were reduced when they were exposed to NH3 but the THCs were higher (P < 0.05) in marron fed Bio-Mos diets. Vibrio spp. in haemolymph of marron fed the control diet significantly increased when they were infected with V. mimicus and challenged with NH3 but it remained unchanged in the marron fed the Bio-Mos diets. Haemolymph clotting time was higher in marron fed the control diets when subjected to live transportation and 3 days of exposure to NH3. After 96 h infection marron fed the Bio-Mos diets had longer NRR time than those fed the control diet. All the findings demonstrated the ability of Bio-Mos to improve the survival, health status and immunity of marron under the bacterial infection and stress conditions caused by air and NH3 exposures.

Acute toxic responses as well as uptake and depuration rates for tributyltin (TBT) and dibutyltin (DBT) were examined in the small planktonic shrimp, Acetes intermedius. The 72-h LC(50) values of TBT and DBT for the shrimp were found to be 18.6 and 82.6 microg L(-1) as tin. The uptake rate constants of TBT and DBT in the shrimp were 0.0006 and 0.0002 L g(-1) h(-1), and the corresponding depuration rate constants were 0.0303 and 0.0106 h(-1), respectively. It appears that real-time ambient TBT pollution status can be more closely reflected in this species. The shrimp may serve as a biomonitor to indicate short-term fluctuations in ambient TBT pollution. A field survey was also conducted to distinguish contrasts in butyltin accumulation under different ambient conditions. These observations provide valuable information for the evaluation of TBT pollution status in the environment using A. intermedius as a biomonitor.

Deltamethrin is a pyrethroid insecticide used extensively to control invertebrate pests on cotton and other crops. It is acutely toxic to nontarget aquatic organisms, but existing toxicity data are mostly from toxicity tests using purified laboratory water that differs greatly from the turbid, high-conductivity rivers in the cotton-growing regions of Australia. The aim of this study was to determine whether the water quality variables conductivity, suspended particles, and dissolved organic matter alter the toxicity of deltamethrin to freshwater crustaceans and a fish. We tested three Australian native species: a cladoceran (Ceriodaphnia cf. dubia), a freshwater shrimp (Paratya australiensis), and larvae of the eastern rainbow fish (Melanotaenia duboulayi). Conductivity of the test solutions ranged from 200 to 750 microS/cm, but such changes did not modify the toxicity of deltamethrin to any of the test species. However, the toxicity of deltamethrin to C. cf. dubia and P. australiensis in river water was significantly decreased (1.8-fold to 6.3-fold reduction) compared to that in laboratory water. Variability in the toxicity data limited our ability to detect differences between laboratory and river water for M. duboulayi. Despite reductions in toxicity in natural waters, deltamethrin remained highly toxic [all L(E)C(50) values <0.26 microg/L] to all organisms tested; thus, further investigation of the hazard of deltamethrin is warranted.

The bioaccumulation and elimination capacity of chromium were examined in four freshwater species: the submersed aquatic plant Ceratophyllum demersum (Ceratophyllaceae), the oligochaete Limnodrilus udekemianus (Tubificidae), the crab Zilchiopsis collastinensis (Decapoda), and the fish Cnesterodon decemmaculatus (Poeciliidae). All of the species were exposed simultaneously to sediments spiked with Cr (K(2)Cr(2)O(7)) at different concentrations for 28 days, followed by 7 days without Cr to evaluate the concentration of residual Cr. We found that Cr accumulated in the tissues of all four species. The highest bioconcentration factor obtained for each species is as follows: C. demersum, 718.66 (+/-272.91); L. udekemianus, 172.55 (+/-80.8), Z. collastinensis, 67.72 (+/-35.4); C. decemmaculatus, 23.11 (+/-12.82), all at 28 days of exposure.

This study investigated the lethal and sublethal effects of the pyrethroid insecticide bifenthrin on adult and larval grass shrimp, Palaemonetes pugio, and adult sheepshead minnows, Cyprinodon variegatus. The effects were determined by conducting 96-h aqueous static renewal tests and 24-h static tests with sediment. Oxidative stress biomarkers, lipid peroxidation, glutathione, and catalase were also assessed. The 96-h aqueous LC50 value for adult shrimp was 0.020 microg/L (95% CI: 0.015-0.025 microg/L) and for larval shrimp was 0.013 microg/L (95% CI: 0.011-0.016 microg/L). The 96-h aqueous LC50 for adult sheepshead minnow was 19.806 microg/L (95% CI: 11.886-47.250 microg/L). The 24-h sediment LC50 for adult shrimp was 0.339 microg/L (95% CI: 0.291-0.381 microg/L) and for larval shrimp was 0.210 microg/L (95% CI: 0.096-0.393 microg/L). The oxidative stress assays showed some increasing trends toward physiological stress with increased bifenthrin concentrations but they were largely inconclusive. Given the sensitivity of grass shrimp to this compound in laboratory bioassays, additional work will be needed to determine if these exposure levels are environmentally relevant.

Cobalt (II), copper (II), nickel (II) and zinc (II) complexes with 2-hydroxy-1-naphthaldehyde derived N-substituted sulfonamides have been synthesized and the nature of bonding and structure of compounds have been deduced from physical, analytical and spectral (IR, (1)H NMR, (13)C NMR, Mass and electronic) data. An octahedral geometry has been suggested for the complexes. Complexes along with the ligands were assessed for their antibacterial and antifungal activities on different species of pathogenic bacteria and fungi. The results revealed the ligands to possess moderate to significant antibacterial activity which was, in many cases, enhanced on chelation. Similar results were observed for antifungal activity. Brine shrimp bioassay was also carried out for in vitro cytotoxic properties against Artemia salina.

Lethal and sublethal effects of Cadmium and Zinc on two freshwater crustaceans were investigated. The 96-h LC50 for Cadmium and Zinc were 42.20 microg l(-1) and 5.43 mg l(-1) for Atyaephyra desmarestii, and 36.17 microg l(-1) and 4.61 mg l(-1) for Echinogammarus meridionalis, respectively. An increase in metal concentrations at sublethal levels resulted in significant reductions of the feeding rate of both species. The LOECs in the chronic feeding assays for Zinc were 1.29 mg l(-1) for A. desmarestii and 0.4 mg l(-1) for E. meridionalis. For Cadmium the LOEC was 6.53 microgl(-1) for both species. The results suggest the potential use of these two crustacean species as test organisms in ecotoxicological tests. Feeding assays appear to be a rapid, cheap and effective tool to be used in biomonitoring studies of Portuguese freshwaters.