Subjects -> BIOLOGY (Total: 3447 journals)
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BIOLOGY (1643 journals)                  1 2 3 4 5 6 7 8 | Last

Showing 1 - 200 of 1720 Journals sorted alphabetically
AAPS Journal     Hybrid Journal   (Followers: 30)
Achievements in the Life Sciences     Open Access   (Followers: 8)
ACS Pharmacology & Translational Science     Hybrid Journal   (Followers: 2)
ACS Synthetic Biology     Hybrid Journal   (Followers: 31)
Acta Biologica Colombiana     Open Access   (Followers: 7)
Acta Biologica Hungarica     Full-text available via subscription   (Followers: 5)
Acta Biologica Sibirica     Open Access   (Followers: 2)
Acta Biologica Turcica     Open Access   (Followers: 1)
Acta Biologica Venezuelica     Open Access  
Acta Biomaterialia     Hybrid Journal   (Followers: 30)
Acta Biotheoretica     Hybrid Journal   (Followers: 3)
Acta Chiropterologica     Full-text available via subscription   (Followers: 6)
acta ethologica     Hybrid Journal   (Followers: 4)
Acta Fytotechnica et Zootechnica     Open Access   (Followers: 1)
Acta Limnologica Brasiliensia     Open Access   (Followers: 4)
Acta Médica Costarricense     Open Access   (Followers: 2)
Acta Musei Silesiae, Scientiae Naturales     Open Access   (Followers: 1)
Acta Neurobiologiae Experimentalis     Open Access  
Acta Parasitologica     Hybrid Journal   (Followers: 12)
Acta Scientiae Biological Research     Open Access   (Followers: 1)
Acta Scientiarum. Biological Sciences     Open Access   (Followers: 2)
Acta Scientifica Naturalis     Open Access   (Followers: 3)
Acta Universitatis Agriculturae et Silviculturae Mendelianae Brunensis     Open Access   (Followers: 1)
Actualidades Biológicas     Open Access   (Followers: 1)
Advanced Biosystems     Hybrid Journal  
Advanced Health Care Technologies     Open Access   (Followers: 10)
Advanced Journal of Graduate Research     Open Access   (Followers: 1)
Advanced Nonlinear Studies     Hybrid Journal  
Advanced Quantum Technologies     Hybrid Journal  
Advanced Studies in Biology     Open Access   (Followers: 1)
Advances in Antiviral Drug Design     Full-text available via subscription   (Followers: 2)
Advances in Bioinformatics     Open Access   (Followers: 20)
Advances in Biological Regulation     Hybrid Journal   (Followers: 4)
Advances in Biology     Open Access   (Followers: 12)
Advances in Cell Biology/ Medical Journal of Cell Biology     Open Access   (Followers: 30)
Advances in Cellular and Molecular Biology of Membranes and Organelles     Full-text available via subscription   (Followers: 14)
Advances in Developmental Biology     Full-text available via subscription   (Followers: 14)
Advances in DNA Sequence-Specific Agents     Full-text available via subscription   (Followers: 7)
Advances in Ecological Research     Full-text available via subscription   (Followers: 44)
Advances in Environmental Sciences - International Journal of the Bioflux Society     Open Access   (Followers: 19)
Advances in Enzyme Research     Open Access   (Followers: 11)
Advances in Experimental Biology     Full-text available via subscription   (Followers: 9)
Advances in Genome Biology     Full-text available via subscription   (Followers: 11)
Advances in High Energy Physics     Open Access   (Followers: 22)
Advances in Human Biology     Open Access   (Followers: 5)
Advances in Life Science and Technology     Open Access   (Followers: 20)
Advances in Life Sciences     Open Access   (Followers: 7)
Advances in Marine Biology     Full-text available via subscription   (Followers: 21)
Advances in Molecular and Cell Biology     Full-text available via subscription   (Followers: 26)
Advances in Organ Biology     Full-text available via subscription   (Followers: 2)
Advances in Planar Lipid Bilayers and Liposomes     Full-text available via subscription   (Followers: 3)
Advances in Space Biology and Medicine     Full-text available via subscription   (Followers: 7)
Advances in Structural Biology     Full-text available via subscription   (Followers: 6)
Advances in Tropical Biodiversity and Environmental Sciences     Open Access   (Followers: 3)
Advances in Virus Research     Full-text available via subscription   (Followers: 6)
Adversity and Resilience Science : Journal of Research and Practice     Hybrid Journal   (Followers: 1)
African Journal of Range & Forage Science     Hybrid Journal   (Followers: 12)
AFRREV STECH : An International Journal of Science and Technology     Open Access   (Followers: 3)
Ageing Research Reviews     Hybrid Journal   (Followers: 12)
Aging Cell     Open Access   (Followers: 26)
Agrokémia és Talajtan     Full-text available via subscription   (Followers: 2)
Agrokreatif Jurnal Ilmiah Pengabdian kepada Masyarakat     Open Access  
AJP Cell Physiology     Hybrid Journal   (Followers: 18)
AJP Endocrinology and Metabolism     Hybrid Journal   (Followers: 25)
AJP Lung Cellular and Molecular Physiology     Hybrid Journal   (Followers: 3)
Al-Kauniyah : Jurnal Biologi     Open Access  
Alasbimn Journal     Open Access   (Followers: 2)
Alces : A Journal Devoted to the Biology and Management of Moose     Open Access  
AMB Express     Open Access   (Followers: 1)
Ambix     Hybrid Journal   (Followers: 3)
American Biology Teacher     Full-text available via subscription   (Followers: 14)
American Fern Journal     Full-text available via subscription   (Followers: 1)
American Journal of Agricultural and Biological Sciences     Open Access   (Followers: 9)
American Journal of Bioethics     Hybrid Journal   (Followers: 16)
American Journal of Human Biology     Hybrid Journal   (Followers: 18)
American Journal of Medical and Biological Research     Open Access   (Followers: 10)
American Journal of Plant Sciences     Open Access   (Followers: 21)
American Journal of Primatology     Hybrid Journal   (Followers: 16)
American Malacological Bulletin     Full-text available via subscription   (Followers: 3)
American Naturalist     Full-text available via subscription   (Followers: 81)
Amphibia-Reptilia     Hybrid Journal   (Followers: 6)
Anadol University Journal of Science and Technology B : Theoritical Sciences     Open Access  
Anadolu University Journal of Science and Technology : C Life Sciences and Biotechnology     Open Access   (Followers: 2)
Anaerobe     Hybrid Journal   (Followers: 4)
Anales de Biología     Open Access   (Followers: 2)
Analytical Methods     Full-text available via subscription   (Followers: 13)
Anatomical Science International     Hybrid Journal   (Followers: 3)
Animal Cells and Systems     Hybrid Journal   (Followers: 5)
Animal Models and Experimental Medicine     Open Access  
Annales de Limnologie - International Journal of Limnology     Hybrid Journal   (Followers: 1)
Annales françaises d'Oto-rhino-laryngologie et de Pathologie Cervico-faciale     Full-text available via subscription   (Followers: 3)
Annales Henri Poincaré     Hybrid Journal   (Followers: 3)
Annales Universitatis Mariae Curie-Sklodowska, sectio C – Biologia     Open Access   (Followers: 1)
Annals of Applied Biology     Hybrid Journal   (Followers: 8)
Annals of Biomedical Engineering     Hybrid Journal   (Followers: 19)
Annals of Human Biology     Hybrid Journal   (Followers: 6)
Annals of Science and Technology     Open Access  
Annual Research & Review in Biology     Open Access   (Followers: 2)
Annual Review of Biomedical Engineering     Full-text available via subscription   (Followers: 15)
Annual Review of Biophysics     Full-text available via subscription   (Followers: 26)
Annual Review of Cancer Biology     Full-text available via subscription   (Followers: 4)
Annual Review of Cell and Developmental Biology     Full-text available via subscription   (Followers: 42)
Annual Review of Food Science and Technology     Full-text available via subscription   (Followers: 15)
Annual Review of Genomics and Human Genetics     Full-text available via subscription   (Followers: 27)
Annual Review of Phytopathology     Full-text available via subscription   (Followers: 13)
Anthropological Review     Open Access   (Followers: 24)
Antibiotics     Open Access   (Followers: 9)
Antioxidants     Open Access   (Followers: 5)
Antioxidants & Redox Signaling     Hybrid Journal   (Followers: 9)
Antonie van Leeuwenhoek     Hybrid Journal   (Followers: 5)
Anzeiger für Schädlingskunde     Hybrid Journal   (Followers: 1)
Apidologie     Hybrid Journal   (Followers: 5)
Apmis     Hybrid Journal   (Followers: 2)
APOPTOSIS     Hybrid Journal   (Followers: 9)
Applied Biology     Open Access   (Followers: 2)
Applied Bionics and Biomechanics     Open Access   (Followers: 7)
Applied Vegetation Science     Full-text available via subscription   (Followers: 10)
Aquaculture Environment Interactions     Open Access   (Followers: 4)
Aquaculture International     Hybrid Journal   (Followers: 26)
Aquaculture Reports     Open Access   (Followers: 3)
Aquaculture, Aquarium, Conservation & Legislation - International Journal of the Bioflux Society     Open Access   (Followers: 7)
Aquatic Biology     Open Access   (Followers: 8)
Aquatic Ecology     Hybrid Journal   (Followers: 38)
Aquatic Ecosystem Health & Management     Hybrid Journal   (Followers: 16)
Aquatic Science and Technology     Open Access   (Followers: 4)
Aquatic Toxicology     Hybrid Journal   (Followers: 24)
Archaea     Open Access   (Followers: 4)
Archiv für Molluskenkunde: International Journal of Malacology     Full-text available via subscription   (Followers: 3)
Archives of Biological Sciences     Open Access  
Archives of Microbiology     Hybrid Journal   (Followers: 10)
Archives of Natural History     Hybrid Journal   (Followers: 8)
Archives of Oral Biology     Hybrid Journal   (Followers: 3)
Archives of Virology     Hybrid Journal   (Followers: 5)
Archivum Immunologiae et Therapiae Experimentalis     Hybrid Journal   (Followers: 2)
Arid Ecosystems     Hybrid Journal   (Followers: 3)
Arquivos do Instituto Biológico     Open Access   (Followers: 1)
Arquivos do Museu Dinâmico Interdisciplinar     Open Access  
Arthropod Structure & Development     Hybrid Journal   (Followers: 2)
Arthropods     Open Access   (Followers: 1)
Artificial DNA: PNA & XNA     Hybrid Journal   (Followers: 3)
Asian Bioethics Review     Full-text available via subscription   (Followers: 3)
Asian Journal of Biodiversity     Open Access   (Followers: 5)
Asian Journal of Biological Sciences     Open Access   (Followers: 3)
Asian Journal of Biology     Open Access   (Followers: 2)
Asian Journal of Biotechnology and Bioresource Technology     Open Access   (Followers: 1)
Asian Journal of Cell Biology     Open Access   (Followers: 6)
Asian Journal of Developmental Biology     Open Access   (Followers: 3)
Asian Journal of Medical and Biological Research     Open Access   (Followers: 5)
Asian Journal of Nematology     Open Access   (Followers: 4)
Asian Journal of Poultry Science     Open Access   (Followers: 5)
Atti della Accademia Peloritana dei Pericolanti - Classe di Scienze Medico-Biologiche     Open Access  
Australian Life Scientist     Full-text available via subscription   (Followers: 2)
Australian Mammalogy     Hybrid Journal   (Followers: 8)
Autophagy     Hybrid Journal   (Followers: 4)
Avian Biology Research     Full-text available via subscription   (Followers: 6)
Avian Conservation and Ecology     Open Access   (Followers: 15)
Bacterial Empire     Open Access   (Followers: 1)
Bacteriology Journal     Open Access   (Followers: 1)
Bacteriophage     Full-text available via subscription   (Followers: 3)
Bangladesh Journal of Bioethics     Open Access  
Bangladesh Journal of Plant Taxonomy     Open Access  
Bangladesh Journal of Scientific Research     Open Access   (Followers: 1)
Batman Üniversitesi Yaşam Bilimleri Dergisi     Open Access  
Berita Biologi     Open Access   (Followers: 1)
Between the Species     Open Access   (Followers: 1)
Bio Tribune Magazine     Hybrid Journal  
BIO Web of Conferences     Open Access  
BIO-Complexity     Open Access  
Bio-Grafía. Escritos sobre la Biología y su enseñanza     Open Access  
Bio-Lectura     Open Access  
BIO-SITE : Biologi dan Sains Terapan     Open Access   (Followers: 1)
Bioanalytical Reviews     Hybrid Journal   (Followers: 2)
Biocatalysis and Biotransformation     Hybrid Journal   (Followers: 6)
BioCentury Innovations     Full-text available via subscription   (Followers: 2)
Biochemistry and Cell Biology     Hybrid Journal   (Followers: 17)
Biochimie     Hybrid Journal   (Followers: 6)
BioControl     Hybrid Journal   (Followers: 6)
Biocontrol Science and Technology     Hybrid Journal   (Followers: 8)
Biodemography and Social Biology     Hybrid Journal  
BIODIK : Jurnal Ilmiah Pendidikan Biologi     Open Access   (Followers: 1)
BioDiscovery     Open Access   (Followers: 2)
Biodiversidade e Conservação Marinha : Revista CEPSUL     Open Access  
Biodiversitas : Journal of Biological Diversity     Open Access  
Biodiversity Data Journal     Open Access   (Followers: 4)
Biodiversity Informatics     Open Access   (Followers: 1)
Biodiversity Information Science and Standards     Open Access   (Followers: 2)
Biodiversity: Research and Conservation     Open Access   (Followers: 27)
Bioedukasi : Jurnal Pendidikan Biologi FKIP UM Metro     Open Access  
Bioeksperimen : Jurnal Penelitian Biologi     Open Access  
Bioelectrochemistry     Hybrid Journal   (Followers: 2)
Bioelectromagnetics     Hybrid Journal   (Followers: 2)
Bioenergy Research     Hybrid Journal   (Followers: 4)
Bioengineering and Bioscience     Open Access   (Followers: 3)
BioEssays     Hybrid Journal   (Followers: 11)
Bioethics     Hybrid Journal   (Followers: 18)
BioéthiqueOnline     Open Access  
Biofabrication     Hybrid Journal   (Followers: 5)
Biofilms     Full-text available via subscription   (Followers: 2)
Biogeosciences (BG)     Open Access   (Followers: 12)
Biogeosciences Discussions (BGD)     Open Access   (Followers: 3)

        1 2 3 4 5 6 7 8 | Last

Similar Journals
Journal Cover
Aquatic Toxicology
Journal Prestige (SJR): 1.456
Citation Impact (citeScore): 4
Number of Followers: 24  
 
  Hybrid Journal Hybrid journal (It can contain Open Access articles)
ISSN (Print) 0166-445X - ISSN (Online) 1879-1514
Published by Elsevier Homepage  [3204 journals]
  • Effects of tris (2-chloroethyl) phosphate (TCEP) on growth, reproduction
           and gene transcription in the protozoan Tetrahymena thermophila
    • Abstract: Publication date: Available online 26 March 2020Source: Aquatic ToxicologyAuthor(s): Hui Hao, Siliang Yuan, Shiyang Cheng, Qian Sun, John P. Giesy, Chunsheng Liu
       
  • Toxicological screening of marine red algae Champia parvula (C. Agardh)
           against the dengue mosquito vector Aedes aegypti (Linn.) and its
           non-toxicity against three beneficial aquatic predators
    • Abstract: Publication date: Available online 19 March 2020Source: Aquatic ToxicologyAuthor(s): Parthiban Yogarajalakshmi, Thinnaur Venugopal Poonguzhali, Raja Ganesan, Sengodan Karthi, Sengottayan Senthil-Nathan, Patcharin Krutmuang, Narayanaswamy Radhakrishnan, Faruq Mohammad, Tae-Jin Kim, Prabhakaran Vasantha-Srinivasan
       
  • The effects of chronic cadmium exposure on Bufo gargarizans larvae:
           Histopathological impairment, gene expression alteration and fatty acid
           metabolism disorder in the liver
    • Abstract: Publication date: May 2020Source: Aquatic Toxicology, Volume 222Author(s): Zongqi Ju, Jing Ya, Xinyi Li, Hongyuan Wang, Hongfeng Zhao
       
  • Antibiotics induced alterations in cell density, photosynthesis,
           microcystin synthesis and proteomic expression of Microcystis aeruginosa
           during CuSO4 treatment
    • Abstract: Publication date: Available online 16 March 2020Source: Aquatic ToxicologyAuthor(s): Yunhan Jiang, Ying Liu, Jian Zhang
       
  • Temperature determines the rate at which retene affects trout embryos, not
           the concentration that is toxic
    • Abstract: Publication date: Available online 12 March 2020Source: Aquatic ToxicologyAuthor(s): Jani O. Honkanen, Christopher B. Rees, Jussi V.K. Kukkonen, Peter V. Hodson
       
  • Transcription activation of β-carotene biosynthetic genes at the initial
           stage of stresses as an indicator of the increased β-carotene
           accumulation in isolated Dunaliella salina strain GY-H13
    • Abstract: Publication date: Available online 12 March 2020Source: Aquatic ToxicologyAuthor(s): Qing-Ling Zhu, Jia-Lang Zheng, Jianhua Liu
       
  • Exposure to phthalates impaired neurodevelopment through estrogenic
           effects and induced DNA damage in neurons
    • Abstract: Publication date: Available online 10 March 2020Source: Aquatic ToxicologyAuthor(s): Shisan Xu, Huan Zhang, Ping-Chieh Pao, Audrey Lee, Jun Wang, Yu Suen Chan, Francis A.M. Manno, Shun Wan Chan, Shuk Han Cheng, Xueping Chen
       
  • Ecotoxicity and Interacting Mechanism of Anionic Surfactant Sodium Dodecyl
           Sulfate (SDS) and Nonionic Surfactant Fatty Alcohol-polyoxyethlene ether
           (AEO)
    • Abstract: Publication date: Available online 9 March 2020Source: Aquatic ToxicologyAuthor(s): Weimo Han, Mengchun Hou, Faming He, Wenhua Zhang, Bi Shi
       
  • Interaction between hypoxia and perfluorobutane sulfonate on developmental
           toxicity and endocrine disruption in marine medaka embryos
    • Abstract: Publication date: Available online 9 March 2020Source: Aquatic ToxicologyAuthor(s): Lizhu Tang, Mengyuan Liu, Shiwen Song, Chenyan Hu, Paul K.S. Lam, James C.W. Lam, Lianguo Chen
       
  • Ultraviolet-B radiation induces transcriptional modulation of components
           associated with the extracellular matrix in embryos of decapod
           Macrobrachium olfersii
    • Abstract: Publication date: Available online 9 March 2020Source: Aquatic ToxicologyAuthor(s): Thiciane Patrycia Gonçalves dos Santos, Madson Silveira de Melo, Heloisa Schramm, Yara Maria Rauh Müller, Michael Jaramillo Bobadilla, Evelise Maria Nazari
       
  • Optimal number of Fucus vesiculosus subsamples to differentiate between
           sites affected by distinct levels of heavy metal contamination
    • Abstract: Publication date: Available online 4 March 2020Source: Aquatic ToxicologyAuthor(s): R. García-Seoane, J.R. Aboal, J.A. Fernández
       
  • New findings on the effect of glyphosate on autotrophic and heterotrophic
           picoplankton structure: a microcosm approach
    • Abstract: Publication date: Available online 3 March 2020Source: Aquatic ToxicologyAuthor(s): Sabio y García Carmen Alejandra, Schiaffino María Romina, Lozano Verónica Laura, Vera María Solange, Ferraro Marcela, Izaguirre Irina, Pizarro Haydée
       
  • The genome of the harpacticoid copepod Tigriopus japonicus: Potential for
           its use in marine molecular ecotoxicology
    • Abstract: Publication date: Available online 2 March 2020Source: Aquatic ToxicologyAuthor(s): Chang-Bum Jeong, Bo-Young Lee, Beom-Soon Choi, Min-Sub Kim, Jun Chul Park, Duck-Hyun Kim, Minghua Wang, Heum Gi Park, Jae-Seong Lee
       
  • A method for CRISPR/Cas9 mutation of genes in fathead minnow
           (Pimephales promelas)
    • Abstract: Publication date: Available online 2 March 2020Source: Aquatic ToxicologyAuthor(s): Jennifer A. Maki, Jenna E. Cavallin, Kevin G. Lott, Travis W. Saari, Gerald T. Ankley, Daniel L. Villeneuve
       
  • The importance of diet-related effects of the antibiotic ciprofloxacin on
           the leaf-shredding invertebrate Gammarus fossarum (Crustacea; Amphipoda)
    • Abstract: Publication date: Available online 29 February 2020Source: Aquatic ToxicologyAuthor(s): Marco Konschak, Jochen P. Zubrod, Patrick Baudy, Patrick Fink, Kilian Kenngott, Simon Lüderwald, Katja Englert, Cynthia Jusi, Ralf Schulz, Mirco Bundschuh
       
  • Effect of Louisiana Sweet Crude Oil on a Pacific Coral, Pocillopora
           damicornis
    • Abstract: Publication date: Available online 28 February 2020Source: Aquatic ToxicologyAuthor(s): Lisa A. May, Athena R. Burnett, Carl V. Miller, Emily Pisarski, Laura F. Webster, Zachary J. Moffitt, Paul Pennington, Edward Wirth, Greg Baker, Robert Ricker, Cheryl M. Woodley
       
  • Presence of CTXs in moray eels and dusky groupers in the marine
           environment of the Canary Islands
    • Abstract: Publication date: April 2020Source: Aquatic Toxicology, Volume 221Author(s): Andres Sanchez-Henao, Natalia García-Álvarez, Freddy Silva Sergent, Pablo Estévez, Ana Gago-Martínez, Francisco Martín, María Ramos-Sosa, Antonio Fernández, Jorge Diogène, Fernando Real
       
  • Structure and functional analysis reveal an important regulated role of
           arginine kinase in Patinopecten yessoensis under low pH stress
    • Abstract: Publication date: Available online 19 February 2020Source: Aquatic ToxicologyAuthor(s): Zujing Yang, Xiaoting Huang, Huan Liao, Zhengrui Zhang, Fanhua Sun, Sihua Kou, Zhenmin Bao Arginine kinase (AK), an important member of the phosphokinase family, is involved in temporal and spatial adenosine triphosphate (ATP) buffering systems. AK plays an important role in physiological function and metabolic regulations, in particular tissues with high and fluctuating energy demands. In present study, four AK genes were firstly identified from Yesso scallop (Patinopecten yessoensis) genome, respectively named PyAK1-4. PyAKs have highly conserved structures with a six-exon/five-exon structure, except for PyAK3. PyAK3 contains an unusual two-domain structure and a “bridge intron” between the two domains, which may originate from gene duplication and subsequent fusion. Phylogenetic analysis showed that all PyAKs belonged to an AK supercluster together with other AK proteins from Mollusca, Platyhelminthes, Arthropoda, and Nematode. A transcriptome database demonstrated that PyAK3 and PyAK4 were the main functional executors with high expression level during larval development and in adult tissues, while PyAK1 and PyAK2 were expressed at a low level. Furthermore, both PyAK2 and PyAK3 showed notably high expression in the male gonad, and PyAK4 was broadly expressed in almost all tissues with the highest level in striated muscle, indicating a tissue-specific expression pattern of PyAKs. In addition, quantitative real-time PCR results demonstrated that the expression of PyAK2, PyAK3 and PyAK4 were significantly upregulated in response to pH stress, especially in an extremely acidifying condition (pH 6.5), revealing the possible involvement of PyAKs in energetic homeostasis during environmental changes. Collectively, a comprehensive analysis of PyAKs was conducted in P. yessoensis. The diversity of PyAKs and their specific expression patterns promote a better understanding of energy metabolism in the growth, development and environmental response of P. yessoensis.
       
  • Effects of exposing shrimp larvae (Pandalus borealis) to aquaculture
           pesticides at field relevant concentrations, with and without food
           limitation
    • Abstract: Publication date: Available online 18 February 2020Source: Aquatic ToxicologyAuthor(s): Renée Katrin Bechmann, Maj Arnberg, Shaw Bamber, Emily Lyng, Stig Westerlund, Jan Thomas Rundberget, Alfhild Kringstad, Paul J. Seear, Les Burridge Anti-parasitic drugs used in the aquaculture industry are discharged to the sea after treatment of salmon. In this study, the effects of azamethiphos (AZA) in the Salmosan® formulation and deltamethrin (DEL) in the Alpha Max® formulation, have been assessed in Northern shrimp larvae (Pandalus borealis) when administered both separately and in combination. The exposure concentrations were 100 ng/L for AZA and 2 ng/L for DEL, each representing a 1000-fold dilution of the prescribed concentrations for salmon. These two chemicals were combined at these concentrations to give a third treatment (AZA + DEL). When larvae were exposed for two hours on the first, second and third days post hatch (dph), significantly increased mortality and reduced swimming activity were observed for larvae from the DEL and combined AZA + DEL treatments 4 dph, though not in larvae from the AZA treatment. A single pulse exposure, delivered on the first day post hatch, caused similar effects on mortality and swimming activity 4 dph as the three-pulse exposure. Mortality was driven by the presence of DEL in both experiments, with no amplification or reduction of effects observed when DEL and AZA were combined. Larvae were observed for 13 days following the single pulse exposure, with food limitation introduced as an additional stressor on day 4. In the DEL and AZA + DEL treatments mortality continued to increase regardless of food level, with no larvae completing development to stage II. The overriding toxicity of DEL masked any potential effects the reduced food ration may have exerted. Swimming activity was lower for AZA treated larvae than Control larvae 13 dph, when both groups were fed daily, though no other significant changes to mortality, development to stage II, feeding rate or gene expression were observed. Food limited Control and AZA larvae had lower swimming activity and feeding rate than daily fed Control larvae, with expression of pyruvate kinase and myosin genes also downregulated. However, there was no negative effect on survival or successful development to stage II in these treatments. In addition, mesencephalic astrocyte-derived neurotropic factor was downregulated in food limited Control larvae when compared with the daily fed Controls.Results from this study together with reported estimates of dispersion plume concentrations of discharged pesticides indicate that toxic concentrations of deltamethrin could reach shrimp larvae several kilometers from a treated salmon farm.
       
  • Oxidative stress and toxicology of Cu2+ based on surface areas in mixed
           cultures of green alga and cyanobacteria: The pivotal role of H2O2
    • Abstract: Publication date: Available online 18 February 2020Source: Aquatic ToxicologyAuthor(s): Michelle Gallo, David Morse, Heloisa C. Hollnagel, Marcelo P. Barros The toxicity of heavy metals in algal monocultures is well studied and is mediated by reactive oxygen and nitrogen species (ROS/RNS). However, little is known about the toxicity of heavy metals and the mechanisms involved in mixed cultures. Here we examine the oxidative stress and toxic effects of Cu2+ on the green alga Dunaliella salina (DS) and the cyanobacteria Synecochoccus elongata (SE) in both mono- and mixed cultures. We find that both species benefit in mixed cultures and acquire higher resistance to Cu2+ toxicity, with a particularly marked effect on SE. DS has a larger surface area than SE, so increases in the number of DS cells compared to SE diminishes the proportion of SE surface area exposed to Cu2+, and contributes to increasing cyanobacterial resistance in mixed cultures. However, these mixed cultures also display as an unexpected property an increased resistance of DS in mixed cultures. SE and DS cells showed significant differences on the kinetics of H2O2 production and antioxidant capacities. The integrated (overall) redox response of mixed cultures, in terms of total amount of H2O2 produced, was proportional to the total surface area of algal species exposed to Cu2+, independent of algal composition in mixed systems. However, mixed cultures display emergent properties, as the time course of H2O2 accumulation is not a simple function of the composition of the mixed cultures. Emergent properties are also observed in the speed of membrane lipid oxidation by the two species, as measured using mixed cultures in which only one of the two species is labeled using the membrane oxidation indicator C11-BODIPY581/591. We suggest that, in addition to H2O2¸ other redox signals (e.g. NO•) and allelochemicals (auxins, cytokinins, etc.) may be used to construct a complex inter-species communication network. This could allow mixed algal systems, whatever their composition, to integrate their cellular responses and perform as a coherent unit against toxic Cu2+ ions.
       
  • Environmental Risk Assessment (ERA) of Pyriproxyfen in Non-target Aquatic
           Organisms
    • Abstract: Publication date: Available online 18 February 2020Source: Aquatic ToxicologyAuthor(s): Jéssica A.S. Moura, Lília P. Souza-Santos Pyriproxyfen (PPF) is a synthetic substance and an insect juvenile hormone agonist with growth regulating effect. It is used worldwide as a pesticide in agriculture and public health campaigns, including the control of Aedes aegypti proliferation. It has low volatility, high Kow value and high lability in aerobic aquatic systems but is considered persistent in anaerobic systems, with a half-life of 288.9 days. The objective of this study is to survey the environmental contamination by pyriproxyfen in aquatic environmental matrices, to review the acute and chronic toxicity in non-target aquatic organisms and to make a risk assessment for the organisms addressed in the bibliographic survey. Pyriproxyfen quantification studies in aquatic environmental matrices are quite scarce and punctual—not representative of regional and global contamination. The water of the River Júcar (Spain) presented the highest concentration of PPF (99.59 ng L-1) among the matrices analysed, which is equivalent to 1% of the maximum dose allowed by the World Health Organization for use in drinking water. Acute and chronic aquatic toxicity studies with LC50, EC50, LOEC and NOEC values of PPF were compiled and interpreted to evaluate possible risks to non-target aquatic organisms. Pyriproxyfen caused a high risk at concentrations detected in aquatic environments for Daphnia magna, with probable reproductive effects and occasional survival risk. This species was the most sensitive to the pesticide, with the lowest estimated concentration of 50% of effect values, followed by a freshwater fish (Xiphophorus maculatus) and estuarine crustaceans (Eurytemora affinis and Leander tenuicornis). The most resistant organisms to PPF within the endpoints addressed in this review were Danio rerio (zebrafish) and Capitella sp. (polychaete). Through the species sensitivity distribution (SSD), it was possible to estimate HC5 at 0.214 µg L-1 and that 2.3% of the species present high sensitivity to pyriproxyfen in the environmental concentration detected in river water and 25.82% of the species are affected in the concentration allowed for lavicidal use. In order to obtain more accurate risk estimates, we suggest ecotoxicological assessments in other species, covering various taxa, with emphasis on microcrustaceans due to their fundamental role in the aquatic food web and taxonomic proximity to pesticide target organisms. Furthermore, additional studies of contamination in aquatic environmental matrices are required, with particular attention to freshwater and estuarine environments due to the proximity to the sources of pyriproxyfen and environmental characteristics suggesting high accumulation. Thus, it will be possible to estimate realistic exposure levels and risks in different environments, contributing to effective and safe decision making, integrating development, public health and environmental policy.
       
  • Chiral Toxicity of Muscone to Embryonic Zebrafish Heart
    • Abstract: Publication date: Available online 18 February 2020Source: Aquatic ToxicologyAuthor(s): Ming Li, Liang Yao, Hao Chen, Xuan Ni, Yao Xu, Wengjing Dong, Mingliang Fang, Da Chen, Aowuliji, Liang Xu, Baoquan Zhao, Jiang Deng, Kevin WH. Kwok, Jingfeng Yang, Wu Dong Musk compounds are often used as to treat heart-related diseases and are widely used in Asia. Muscone is one of the most important physiologically active compounds of natural musk. Muscone is a chiral compound and can be further classified into S-muscone and R-muscone and both are present in synthetic musk. While these two chiral isomers have significant differences in odor properties, their difference in toxicity is still unknown. This study used zebrafish as an animal model to compare cardiac toxicities of S-muscone and R-muscone. Results showed that both compounds were acutely toxic to zebrafish embryos causing mortality, decreased hatching rate, pericardial edema, and decreased heart beat rate. These toxicities were modulated through increased Myh6 and Myh7 mRNA expression, and decreased thyroid genes (Trh, Thrβ, and Dio3) expression. R-muscone caused higher toxicity than S-muscone at the same concentration. For safety, the chiral isomer composition of synthetic muscone should be carefully regulated in the future.Graphical abstractGraphical abstract for this article
       
  • Reproductive cycle progression arrest and modification of cell morphology
           (shape and biovolume) in the alga Pseudokirchneriella subcapitata exposed
           to metolachlor
    • Abstract: Publication date: Available online 17 February 2020Source: Aquatic ToxicologyAuthor(s): Manuela D. Machado, Eduardo V. Soares Metolachlor (MET) is an herbicide widely used and frequently found (at µg L-1) in aquatic systems. This work aimed to study the modes of action of MET on the green microalga Pseudokirchneriella subcapitata. Algae exposed to 115 or 235 µg L-1 MET, for 48 or 72 h, presented a reduction of metabolic activity, chlorophyll a and b content and photosynthetic efficiency. The exposure to 115 or 235 µg L-1 MET also induced growth yield reduction, mean cell biovolume increase and alteration of the typical algae shape (cells lunate or helically twisted) to “French croissant”-type; at these MET concentrations, algal population was mainly composed by multinucleated cells (≥ 4 nuclei), which suggest that MET impairs the normal progression of the reproductive cycle but did not hinder nuclear division. The accumulation of multinucleated cells seems to be the consequence of the incapacity of the parent cell to release the autospores. In conclusion, MET disrupts the physiology of P. subcapitata cells; the disturbance of the progression of the reproductive cycle should be in the origin of growth slowdown (or even its arrest), increase of mean cell biovolume and modification of algal shape. This work contributed to elucidate, in a systematically and integrated way, the toxic mechanism of MET on the non-target organism, the alga P. subcapitata.Graphical Graphical abstract for this article
       
  • Plastic Pellets Trigger Feeding Responses in Sea Anemones
    • Abstract: Publication date: Available online 12 February 2020Source: Aquatic ToxicologyAuthor(s): Zoie Diana, Natasha Sawickij, Nelson A. Rivera, Heileen Hsu-Kim, Daniel Rittschof Multiple mechanisms for plastic consumption by marine animals have been proposed based on the feeding cues and behavior of the animal studied. We investigated plastic consumption in sea anemones. We found that anemones readily consumed pristine National Institute of Standards and Technology low-density polyethylene and high-density polyethylene II and III pre-production pellets. Anemone weight, crown area, and number of tentacles were measured before and after 12 days of daily pellet consumption. Crown area significantly increased for control anemones only. Fresh anemones were then sequentially fed consumed and egested pellets from two of the earlier daily trials to measure feeding retention time, which decreased over three to four feedings. The concentrations of elements in anemones (zinc, iron, arsenic, manganese, chromium, copper, vanadium, selenium, nickel, cadmium, and cobalt) were similar to control anemones that were not exposed to pellets. Lead concentrations were significantly higher in anemones fed HDPE III pellets as compared to control. Plastic consumption by marine animals might be reduced by reducing the amount of plastic that enters the ocean and understanding the chemical triggers underlying plastic consumption.
       
  • Morphometric and proteomic responses of early-life stage rainbow trout
           (Oncorhynchus mykiss) to the aquatic herbicide diquat dibromide
    • Abstract: Publication date: Available online 12 February 2020Source: Aquatic ToxicologyAuthor(s): Lisa M. McCuaig, Christopher J. Martyniuk, Vicki Lee Marlatt The objective of this study was to examine the acute toxicity and sub-lethal effects of the commercial formulation of diquat dibromide, Reward® Landscape and Aquatic Herbicide, on multiple life stages of rainbow trout. The continuous exposure 96 h LC50 derived for juvenile feeding fry aged 85 d post-hatch was 9.8 mg/L. Rainbow trout eyed embryos and juvenile feeding fry were also exposed to concentrations of Reward® ranging from 0.12 to 10 mg/L during two 24 h pulse exposures separated by 14 d of rearing in fresh water to mimic the manufacturers instructions for direct applications to water bodies. Decreased survival and body morphometrics were evident at 9.3 mg/L during the embryo/alevin exposures, but not in feeding juveniles, indicating a higher sensitivity of the early life stage fish. Quantitative proteomics and subnetwork enrichment analyses were conducted in the livers for both life stages to evaluate protein profiles after exposure to 0.37 mg/L diquat via Reward® exposure. Unique protein profiles were revealed for pre-feeding swim-up fry and for feeding juvenile fish, reflecting differences between the two life stages in sub-cellular responses after diquat dibromide exposure. Hepatic proteome effects were more dramatic in the pre-feeding swim-up fry with 315 proteins differentially expressed between the control and exposed fish while in the later life stage feeding fry, only 84 proteins were different after Reward® exposure. Exposure to Reward® significantly increased RNA/mRNA processes, induced activation of Atk/mTOR and caspase activity, and altered energy homeostasis. Proteomic alterations are associated with reduced growth observed in embryo/alevin at higher exposure concentrations, offering insight into key events underlying growth impairment within the adverse outcome pathway framework. This study is the first to report the sub-cellular and whole organism level effects of diquat dibromide in a commercial formulation and demonstrates that concentrations based on aquatic application rates alter the hepatic proteome.
       
  • Effects of gold nanoparticles in gilthead seabream – a proteomic
           approach
    • Abstract: Publication date: Available online 11 February 2020Source: Aquatic ToxicologyAuthor(s): A. Barreto, A. Carvalho, A. Campos, H. Osório, E. Pinto, A. Almeida, T. Trindade, A.M.V.M. Soares, K. Hylland, S. Loureiro, M. Oliveira Despite the widespread use of nanoparticles (NPs), there are still major gaps of knowledge regarding the impact of nanomaterials in the environment and aquatic animals. The present work aimed to study the effects of 7 and 40 nm gold nanoparticles (AuNPs) – citrate and polyvinylpyrrolidone (PVP) coated – on the liver proteome of the estuarine/marine fish gilthead seabream (Sparus aurata). After 96 h, exposure to AuNP elicited alterations on the abundance of 26 proteins, when compared to the control group. AuNPs differentially affected several metabolic pathways in S. aurata liver cells. Among the affected proteins were those related to cytoskeleton and cell structure, gluconeogenesis, amino acids metabolism and several processes related to protein activity (protein synthesis, catabolism, folding and transport). The increased abundance of proteins associated with energy metabolism (ATP synthase subunit beta), stress response (94 kDa glucose-regulated protein) and cytoskeleton structure (actins and tubulins) may represent the first signs of cellular oxidative stress induced by AuNPs. Although higher gold accumulation was found in the liver of S. aurata exposed to 7 nm PVP-AuNPs, the 7 nm cAuNPs were more bioactive, inducing more effects in liver proteome. Gold accumulated more in the spleen than in the other assessed tissues of S. aurata exposed to AuNPs, highlighting its potential role on the elimination of these NPs.
       
  • 2,2',4,4'-tetrabromodipheny ether (BDE-47) disrupts gonadal development of
           the Africa clawed frog (Xenopus laevis)
    • Abstract: Publication date: April 2020Source: Aquatic Toxicology, Volume 221Author(s): Jin-Bo Li, Yuan-Yuan Li, Yan-Ping Shen, Min Zhu, Xing-Hong Li, Zhan-Fen Qin Previous studies have shown that BDE-47, one of the most abundant polybrominated diphenyl ethers (PBDEs) congeners, has a weak estrogenic activity, but it has remained unclear whether BDE-47 disrupts gonadal development and causes male-to-female sex reversal in lower vertebrates, with limited and controversial data. The present study aimed to determine the effects of BDE-47 on gonadal development in Xenopus laevis, a model amphibian species for studying adverse effects of estrogenic chemicals on reproductive development. X. laevis at stage 45/46 were exposed to BDE-47 (0.5, 5, 50 nM) in semi-static system, with 1 nM 17β-estradiol (E2) as the positive control. When reaching stage 53, tadpoles were examined for gonadal morphology, histology and sex-dimorphic gene expression. The phenotypic sex (gonadal morphology and histology) of each BDE-47-treated tadpole matched its genetic sex, showing no sex-reversal, whereas one half of genetic males treated with E2 displayed ovarian-like features. However, some genetic males (26%) in the 50 nM BDE-47 treatment group were found to contain more germ cells clumping together in the medulla, along with an increasing tendency of the gonad length/kidney length ratio in males, resembling feminizing outcomes of E2. These observations seem to suggest that BDE-47 exerted weak feminizing effects. However, BDE-47 induced increases in expression of both female-biased genes and male-biased genes in two sexes, which disagrees with feminizing outcomes, suggesting complicated effects of BDE-47 on gonadal development. Taken together, all results demonstrate that nanomolar BDE-47 disrupted gonadal development and exerted weak feminizing effects, but not resulted in male-to-female sex reversal in X. laevis.
       
  • The genome of the marine rotifer Brachionus koreanus sheds light on the
           antioxidative defense system in response to 2-ethyl-phenanthrene and
           piperonyl butoxide
    • Abstract: Publication date: Available online 7 February 2020Source: Aquatic ToxicologyAuthor(s): Jun Chul Park, Beom-Soon Choi, Min-Sub Kim, Huahong Shi, Bingsheng Zhou, Heum Gi Park, Jae-Seong Lee Brachionusspp. (Rotifera: Monogononta) have been introduced as ecotoxicological model-organisms that are widely distributed in aquatic environments. Among the Brachionus spp., the monogonont rotifer Brachionus koreanus has been widely used for ecology, ecotoxicology, and evolution, thus, providing the whole genome data of B. koreanus is important for further understandings of in-depth molecular mechanisms. In this study, the completed assembly and characterization of the B. koreanus genome resulted in a total length of 85.7 Mb with 14,975 annotated genes. The final number of scaffolds was 567 with an N50 value and a GC content of 1.86 Mb and 24.35%, respectively. Based on the fully constructed genome database, a total of 24 CYPs, 23 GSTs, two SODs, and a single CAT genes were identified and analyzed antioxidant activities (CAT, SOD, and GST), and transcriptional regulation of the entire CYPs, GSTs, SODs, and CAT in response to 2-ethyl phenanthrene (2-ethyl PHE) and piperonyl butoxide (PBO), to demonstrate the usefulness of the whole genome library of B. koreanus in response xenobiotic-induced oxidative stress. The assembled B. koreanus genome will provide a better understanding on the molecular ecotoxicology in the view of molecular mechanisms underlying toxicological responses, particularly on xenobiotic detoxification processes in the rotifer B. koreanus.Graphic abstractGraphical abstract for this article
       
  • Environmentally relevant mixture of S-metolachlor and its two metabolites
           affects thyroid metabolism in zebrafish embryos
    • Abstract: Publication date: Available online 7 February 2020Source: Aquatic ToxicologyAuthor(s): Eliška Rozmánková, Marek Pípal, Lucie Bláhová, Naveen Njattuvetty Chandran, Bénédicte Morin, Patrice Gonzalez, Luděk Bláha Herbicides and their metabolites are often detected in water bodies where they may cause adverse effects to non-target organisms. Their effects at environmentally relevant concentrations are often unclear, especially concerning mixtures of pesticides. This study thus investigated the impacts of one of the most used herbicides: S-metolachlor and its two metabolites, metolachlor oxanilic acid (MOA) and metolachlor ethanesulfonic acid (MESA) on the development of zebrafish embryos (Danio rerio). Embryos were exposed to the individual substances and their environmentally relevant mixture until 120 hpf (hours post-fertilization). The focus was set on sublethal endpoints such as malformations, hatching success, length of fish larvae, spontaneous movements, heart rate and locomotion. Moreover, expression levels of eight genes linked to the thyroid system disruption, oxidative stress defense, mitochondrial metabolism, regulation of cell cycle and retinoic acid (RA) signaling pathway were analyzed. Exposure to Smetolachlor (1 µg/L) and the pesticide mixture (1 µg/L of each substance) significantly reduced spontaneous tail movements of 21 hpf embryos. Few rare developmental malformations were observed, but only in larvae exposed to more than 100 µg/L of individual substances (craniofacial deformation, non-inflated gas bladder, yolk sac malabsorption) and to 30 µg/L of each substance in the pesticide mixture (spine deformation). No effect on hatching success, length of larvae, heart rate or larvae locomotion were found. Strong responses were detected at the molecular level including induction of p53 gene regulating the cell cycle (the pesticide mixture - 1 µg/L of each substance; MESA 30 µg/L; and MOA 100 µg/L), as induction of cyp26a1 gene encoding cytochrome P450 (pesticide mixture - 1 µg/L of each substance). Genes implicated in the thyroid system regulation (dio2, thra, thrb) were all overexpressed by the environmentally relevant concentrations of the pesticide mixture (1 µg/L of each substance) and MESA metabolite (1 µg/L). Zebrafish thyroid system disruption was revealed by the overexpressed genes, as well as by some related developmental malformations (mainly gas bladder and yolk sac abnormalities), and reduced spontaneous tail movements. Thus, the thyroid system disruption represents a likely hypothesis behind the effects caused by the low environmental concentrations of S-metolachlor, its two metabolites and their mixture.
       
  • Detecting effects of herbicide runoff: the use of Cassiopea maremetens as
           a biomonitor to hexazinone
    • Abstract: Publication date: Available online 6 February 2020Source: Aquatic ToxicologyAuthor(s): Madeline R. McKenzie, Michelle A. Templeman, Michael J. Kingsford Herbicides are an integral part of global agricultural activity but can be advected into local drainages that can discharge to coastal marine systems. Herbicide runoff can impact coastal marine organisms, including those associated with coral reefs and coastal mangrove forests. In this study, the symbiotic sedentary jellyfish Cassiopea maremetens were exposed to analytical grade hexazinone to determine their sensitivity and potential for recovery after exposure to a press herbicide event of 14 days followed by a recovery period of matching duration. Bell surface area, photosynthetic yield (i.e. effective quantum yield, EQY), statolith count and zooxanthellae density were analyzed. Most metrics demonstrated significant decreases when exposed to higher concentrations of hexazinone, while EQY was significantly decreased at exposure concentrations from 31 μg/L hexazinone and above. In contrast, zooxanthellae density (cells/mm2) increased in the highest concentrations compared to control animals. At the end of the exposure period the EC50 for bell surface area, EQY, and statolith count were 176 μg/L, 81.96 μg/L, and 304 μg/L, respectively. Jellyfish were able to recover to similar start values for all measured metrics at the end of the 14-day recovery period, with EQY showing recovery by day 7 of the recovery period. This study demonstrated that statolith counts as an estimate of age were not affected by herbicides. We conclude that the depressed metrics from herbicide related impacts of C. maremetens are effective indicators of a relatively recent herbicide perturbation in that the recovery timeframe for these jellyfish is relatively short.
       
  • Stress under the sun: effects of exposure to low concentrations of
           UV-filter 4- methylbenzylidene camphor (4-MBC) in a marine bivalve filter
           feeder, the Manila clam Ruditapes philippinarum
    • Abstract: Publication date: Available online 3 February 2020Source: Aquatic ToxicologyAuthor(s): Melania Santonocito, Barbara Salerno, Chiara Trombini, Federico Tonini, Marina G. Pintado-Herrera, Gonzálo Martínez-Rodríguez, Julián Blasco, Pablo Antonio Lara-Martín, Miriam Hampel UV filters are a class of emerging contaminants with an annual estimated production of 10,000 tons worldwide that continuously enter aquatic environments. Among UV filters, 4-methylbenzylidenecamphor (4-MBC) is an organic camphor derivative used in the cosmetic industry for its ability to protect the skin against UV, specifically UV B radiation. Individuals of the Japanese clam, Ruditapes philippinarum, were exposed to 4-MBC at environmentally relevant and slightly higher concentrations (nominal: 0, 1, 10, 100 μg L-1) using a semi-static exposure system over a 7-days period followed by a 3-days depuration period (total 10 days) where no 4-MBC was added to the tanks. Assessed mortality reached up to 100% at the highest exposure concentration and a LC50 value of 7.71 µg·L-14-MBC was derived. Environmental risk assessment carried out in a site specific environment, the Cadiz bay in the south of Spain, revealed a potential risk produced by the presence of 4-MBC. Digestive glands tissues were analysed for differential expression of genes encoding proteins involved in the stress response (SOD, MT, GST, EIF1, BCL2, TP53, CAT, 18S, GADPH, GPX, GADD45, THIO9) by RT-qPCR for relative quantification. Results showed that the presence of 4-MBC at environmentally relevant concentrations induced the expression of genes that encode for antioxidant enzymes (GST) and for proteins related to the inhibition of apoptosis (BCL2) and cellular stress (GADD), suggesting a physiological stress response.Graphical abstractGraphical abstract for this article
       
  • Toxicity, transfer and depuration of anatoxin-a (cyanobacterial
           neurotoxin) in medaka fish exposed by single-dose gavage
    • Abstract: Publication date: Available online 2 February 2020Source: Aquatic ToxicologyAuthor(s): Simon Colas, Charlotte Duval, Benjamin Marie The proliferations of cyanobacteria are increasingly prevalent in many rivers and water bodies due especially to eutrophication. This work aims to study in female medaka fish the toxicity, the transfer and the depuration of the anatoxin-a, a neurotoxin produced by benthic cyanobacterial biofilms. This work will provide answers regarding acute toxicity induced by single gavage by anatoxin-a and to the risks of exposure by ingestion of contaminated fish flesh, considering that data on these aspects remain particularly limited.The oral LD50 and NOAEL of a single dose of (±)-anatoxin-a were determined at 11.50 and 6.67 µg.g-1, respectively. Subsequently, the toxico-kinetics of the (±)-anatoxin-a was observed in the guts, the livers and the muscles of female medaka fish for 10 days. Anatoxin-a was quantified by high-resolution qTOF mass spectrometry coupled upstream to a UHPLC chromatographic chain. The toxin could not be detected in the liver after 12 h, and in the gut and muscle after 3 days. Overall, the medaka fish do not appear to accumulate (±)-anatoxin-a and to largely recover after 24 h following a single sub-acute oral liquid exposure at the NOAEL.
       
  • Acute toxicity and clotting times of anticoagulant rodenticides to
           red-toothed (Odonus niger) and black (Melichthys niger) triggerfish,
           fathead minnow (Pimephales promelas), and largemouth bass (Micropterus
           salmoides).
    • Abstract: Publication date: Available online 1 February 2020Source: Aquatic ToxicologyAuthor(s): Rachelle C. Riegerix, Michael Tanner, Robert Gale, Donald E. Tillitt Anticoagulant rodenticides (ARs) are used in rat eradication efforts on island wildlife refuges. AR bait pellets can get into coral reef areas during broadcasting and lead to exposure of non-target organisms, such as marine fishes. The objective of this study was to determine the sensitivity of representative saltwater fishes, Red-toothed triggerfish (Odonus niger) and Black triggerfish (Melichthys niger), and common freshwater fishes, fathead minnow (Pimephales promelas), and largemouth bass (Micropterus salmoides) to first generation ARs, diphacinone (DPN) and chlorophacinone (CPN), as well as a second-generation AR, brodifacoum (BROD). Acute toxicity of ARs was evaluated by single dose, intraperitoneal injections. The median lethal dose (LD50) ranges were 137-175 µg DPN/g, 155-182 µg CPN/g, and 36-48 µg BROD/g for Red-toothed triggerfish and 90-122 µg DPN/g, 125-164 µg CPN/g, and 50-75 µg BROD/g for black triggerfish. Laboratory surrogate test fish species fathead minnow and largemouth bass were of similar sensitivity toward AR-induced toxicity compared to triggerfish based on LD50 values. Sublethal effects on elevated clotting time occurred in dose-dependent fashion in all fish tested. Fish appear to have low sensitivity to AR chemicals as compared to other taxa, in particular mammals and birds, based on across-taxa comparisons of species sensitivity distributions of whole body, single dose acute lethality (LD50 values). The sensitivity of fish to waterborne exposures of ARs has yet to be fully evaluated and indeed may prove more hazardous to fish.Graphical abstractGraphical abstract for this article
       
  • Copper and Cadmium administration induce toxicity and oxidative stress in
           the marine flatworm Macrostomum lignano
    • Abstract: Publication date: Available online 31 January 2020Source: Aquatic ToxicologyAuthor(s): Yuanyuan Ma, Georgina Rivera-Ingraham, Aude Nommick, Ulf Bickmeyer, Thomas Roeder The contamination of coastal regions with different toxicants, including heavy metal ions such as copper and cadmium jeopardize health and survival of organisms exposed to this habitat. To study the effects of high copper and cadmium concentrations in these marine environments, we used the flatworm Macrostomum lignano as a model. This platyhelminth lives in shallow coastal water and is exposed to high concentrations of all toxicants that accumulate in these sea floors. We could show that both, cadmium and copper show toxicity at higher concentrations, with copper being more toxic than cadmium. At concentrations below acute toxicity, a reduced long-term survival was observed for both metal ions. The effects of sublethal doses comprise reduced physical activities, an increase in ROS levels within the worms, and alterations of the mitochondrial biology. Moreover, cell death events were substantially increased in response to sublethal concentrations of both metal ions and stem cell activity was reduced following exposure to higher cadmium concentrations. Finally, the expression of several genes involved in xenobiotic metabolism was substantially altered by this intervention. Taken together, M. lignano has been identified as a suitable model for marine toxicological studies as it allows to quantify several relevant life-history traits as well as of physiological and behavioral read-outs.
       
  • Application of a programmed semi-automated Ulva pertusa bioassay for
           testing single toxicants and stream water quality
    • Abstract: Publication date: Available online 31 January 2020Source: Aquatic ToxicologyAuthor(s): Hojun Lee, Jihae Park, Kisik Shin, Stephen Depuydt, Soyeon Choi, Jonas De Saeger, Taejun Han A toxicity test based on inhibition of reproduction in the green macroalga Ulva pertusa involves quantifying the change in thallus color as reproduction progresses. However, interpretation of this color change is reliant on the skill level of the examiner. This study aimed to validate a new toxicity test based on inhibition of reproduction in the green macroalga U. pertusa using a vital stain and programmed semi-automated analysis (using Image J) of the change in thallus color. The toxicity rank by inverse EC50 values was: irgarol (0.048 mg L-1)> Ag (0.132 mg L-1)> As (0.172 mg L-1)> simazine (0.378 mg L-1)> formaldehyde (0.442 mg L-1)> DCOIT (0.783 mg L-1)> ZnPT (3.556 mg L-1)> medetomidine (11.600 mg L-1)> phenol (29.316 mg L-1)> methanol (2,736 mg L-1)> ethanol (3,306 mg L-1). The sensitivity of the U. pertusa test to stream waters was similar to or lower than those of the commonly-used Lemna minor and Daphnia magna bioassays. The U. pertusa bioassay is sensitive to, and suitable for, testing various toxicants including metals, volatile organic compounds, herbicide, antifouling agents and phenol and can also be applied to testing freshwater quality after salinity adjustment.
       
  • Sublethal Neurotoxicity of Organophosphate Insecticides to Juvenile Coho
           Salmon
    • Abstract: Publication date: Available online 31 January 2020Source: Aquatic ToxicologyAuthor(s): Cathy A. Laetz, David H. Baldwin, Nathaniel L. Scholz For decades, organophosphate (OP) insecticides have been used as chemical control agents in watersheds that support at-risk populations of Pacific salmon throughout western North America. Spray drift, runoff, and other processes transport OPs to critical surface water habitats for migratory salmonids. While most OPs share a common mechanism of action (i.e., inhibition of neuronal acetylcholinesterase, or AChE), they typically vary in toxic potency. Moreover, dose-response relationships for exposure and sublethal neurotoxicity (e.g., brain AChE inhibition) in salmonids have not been defined for many OPs. Here we exposed juvenile coho salmon (Oncorhynchus kisutch) to five common anticholinesterase insecticides (dimethoate, ethoprop, naled, phorate and phosmet) that are widely used on agricultural, commercial, residential, and public lands. Each of the five pesticides produced a concentration-dependent inhibition of AChE enzyme activity. The effective concentration for 50% AChE inhibition (96-hr EC50) indicated the highest toxicity for phorate (EC50 = 0.57 µg/L) followed by phosmet (3.3 µg/L), naled (7.8 µg/L), ethoprop (90.6 µg/L) and dimethoate (273 µg/L). These findings can inform 1) relative hazard analyses for OP use near sensitive aquatic habitats, 2) predictions of sublethal OP mixture toxicity, and 3) ecological risk assessments for threatened or endangered species of Pacific salmon.
       
  • Inhibitory effects of neurotoxin β-N-methylamino-L-alanine on
           fertilization and early development of the sea urchin Lytechinus pictus
    • Abstract: Publication date: Available online 30 January 2020Source: Aquatic ToxicologyAuthor(s): Aifeng Li, Jose Espinoza, Amro Hamdoun Neurotoxin β-N-methylamino-L-alanine (BMAA) has been widely detected in diverse aquatic organisms and hypothesized as an environmental risk to neurodegenerative diseases in humans. However, the knowledge of its toxicity to marine organisms requires attention. In the present study, embryos and sperm of the sea urchin, Lytechinus pictus, were used to assess the toxicity of BMAA. Effects of BMAA on fertilization and development of sea urchin embryos were measured, and its impacts on efflux transport of sea urchin blastula were also assayed. Results demonstrated that the fertilization and development of embryos were significantly inhibited by high concentrations of BMAA above 300 µg L-1. The EC50 values indicated by active swimming larvae and total larvae numbers at 96 HPF (hours post fertilization) were 165 µg L-1 (1.4 µmol L-1) and 329 µg L-1 (2.8 µmol L-1), respectively. Additionally, sperm exposed to BMAA for 10 min significantly reduced the fertilization ratio of sea urchin eggs. However, the ABC transport activity on the cytomembrane of sea urchin blastula was not inhibited by the presence of BMAA at 50 µg L-1, even up to 500 µg L-1. Abnormal division and developmental malformations occurred at different developmental stages for sea urchin embryos exposed to BMAA at 500 µg L-1. The inhibitory effects of BMAA on sea urchin embryos were reported at the first time in this study, for which the toxicological mechanisms will be explored in future studies.
       
  • Environmental exposure of northern pike to a primary wastewater effluent:
           Impact on the lipidomic profile and lipid metabolism
    • Abstract: Publication date: Available online 25 January 2020Source: Aquatic ToxicologyAuthor(s): Christine Dépatie, Magali Houde, Jonathan Verreault Lipids play important roles in growth, reproduction, locomotion, and migration of fish. Municipal effluents, which are complex mixtures of biological and chemical compounds including flame retardants, have been shown to alter lipid metabletabolism in environmentally and experimentally exposed fish. Down-regulation of several genes coding for fatty acid metabolism enzymes has previously been reported in male northern pike (Esox lucius) collected in the St. Lawrence River (QC, Canada) downstream of a major primary wastewater treatment plant (WWTP) point of discharge. The main objective of this study was to investigate the effects of exposure to the Montreal’s WWTP effluent on the lipidomic profile (i.e., fatty acids, acylcarnitines, and phospholipids) as well as the transcription of genes related to lipid metabolism in the liver of northern pike collected upstream and downstream of this WWTP effluent. Halogenated flame retardant concentrations were also determined in pike liver and used as markers of exposure to this effluent. Greater concentrations of saturated and monounsaturated lysophosphatidylcholines (LPCs) and lower concentrations of polyunsaturated LPCs were determined in the liver of pike collected downstream of the WWTP compared to those collected upstream. Lower mRNA levels of peroxisome proliferator-activated receptor alpha (pparα), a major regulator of lipid metabolism, were also measured in pike exposed to Montreal’s WWTP effluent. In addition, the relative contributions (%) of LPC 18:2 and LPC14:0, compounds used as markers of obesity and inflammation, were significantly correlated with halogenated flame retardant concentrations and fish girth. Results of the present study suggest that chronic environmental exposure to a primary WWTP effluent can modulate the transcription of genes related to lipid metabolism, and hence affect the hepatic phospholipid composition of pike from the St. Lawrence River.
       
  • It’s all about the fluxes: temperature influences ion transport and
           toxicity in aquatic insects
    • Abstract: Publication date: Available online 24 January 2020Source: Aquatic ToxicologyAuthor(s): Sarah E. Orr, David B. Buchwalter Many freshwater ecosystems are becoming saltier and/or warmer, but our understanding of how these factors interact and affect the physiology and life history outcomes of most aquatic species remain unknown. We hypothesize that temperature modulates ion transport rates. Since ion transport is energetically expensive, increases in salinity and/or temperature may influence ion flux rates and ultimately, organismal performance. Radiotracer (22Na+, 35SO4-2, and 45Ca2+) experiments with lab-reared mayflies (N. triangulifer) and other field-collected insects showed that increasing temperature generally increased ion transport rates. For example, increasing temperature from 15 °C to 25 °C, increased 22Na+ uptake rates by two-fold (p 
       
  • Effects of diluted bitumen exposure on Atlantic salmon smolts: molecular
           and metabolic responses in relation to swimming performance
    • Abstract: Publication date: Available online 23 January 2020Source: Aquatic ToxicologyAuthor(s): Sean R. Avey, Christopher J. Kennedy, Anthony P. Farrell, Todd E. Gillis, Sarah L. Alderman Canada’s oil sands industry continues to expand and the volume of diluted bitumen (dilbit) transported across North America is increasing, adding to spill risk and environmental contamination. Dilbit exposure is known to cause adverse effects in fish, but linking molecular and cellular changes with ecologically-relevant individual performance metrics is needed to better understand the potential consequences of a dilbit spill into the aquatic environment. Therefore, this study examined the effects of dilbit exposure on subcellular responses in cardiac and skeletal muscle in relation to swimming performance in a migratory fish species at risk of exposure, Atlantic salmon. Smolts were exposed subchronically to environmentally relevant concentrations of the water-soluble fraction of dilbit (WSFd) for 24 d, and then a subset of exposed fish underwent a depuration period of 7 or 14 d, for a total of 3 experimental time points. At each time point, repeat swimming performance was assessed using sequential critical swimming speed tests (Ucrit) separated by a 24 h rest period, and then several tissues were collected to determine biotransformation enzyme activation, energetic responses, and gene expression changes. Ucrit was unaffected in fish exposed to 67.9 μg/L total initial polycyclic aromatic compounds (PAC), but fish showed a decreased reliance on lipid metabolism for adenosine triphosphate (ATP) in the heart that was maintained through 7 d depuration. In contrast, Ucrit increased in fish exposed to 9.65 μg/L PAC, corresponding to an increased reliance on anaerobic metabolic pathways in cardiac and red skeletal muscle, with partial recovery after 7 d depuration. As expected, at both concentrations WSFd hepatic cyp 1A-mediated biotransformation reactions increased, as measured by EROD activity, which remained elevated for 7 d but not after 14 d depuration. Transcript abundance of cyp1a was also increased in muscle tissue and recovered by 14 d depuration. The expression of other stress-related genes increased in white muscle of dilbit-exposed fish, but were largely unchanged in cardiac and red muscle. The transcriptional profile of cardiac tissue was compared to that of sockeye salmon similarly exposed to WSFd in a previous experiment, and is provided in supplemental text. Combined, these results demonstrate that dilbit exposure alters gene expression and enzyme activities related to xenobiotic exposure, cellular stress, and muscle energetics in juvenile Atlantic salmon without impairing swimming performance, and that most of these changes are recoverable within 14 d depuration.
       
  • Effects of diluted bitumen exposure and recovery on the seawater
           acclimation response of Atlantic salmon smolts
    • Abstract: Publication date: Available online 20 January 2020Source: Aquatic ToxicologyAuthor(s): Sarah L. Alderman, Christarin M. Dilkumar, Sean R. Avey, Anthony P. Farrell, Christopher J. Kennedy, Todd E. Gillis Petrogenic chemicals are common and widespread contaminants in the aquatic environment. In Canada, increased extraction of bitumen from the oil sands and transport of the major crude oil export product, diluted bitumen (dilbit), amplifies the risk of a spill and contamination of Canadian waterways. Fish exposed to sublethal concentrations of crude oil can experience a variety of adverse physiological effects including osmoregulatory dysfunction. As regulation of water and ion balance is crucial during the seawater transition of anadromous fish, the hypothesis that dilbit impairs seawater acclimation in Atlantic salmon smolts (a fish at risk of exposure in Canada) was tested. Smolts were exposed for 24 d to the water-soluble fraction of dilbit in freshwater, and then transferred directly to seawater or allowed a 1 wk depuration period in uncontaminated freshwater prior to seawater transfer. The seawater acclimation response was quantified at 1 and 7 d post-transfer using established hematological, tissue, and molecular endpoints including gill Na+/K+-ATPase gene expression (nka). All smolts, irrespective of dilbit exposure, increased serum Na+ concentrations and osmolality within 1 d of seawater transfer. The recovery of these parameters to freshwater values by 7 d post-transfer was likely driven by the increased expression and activity of Na+/K+-ATPase in the gill. Histopathological changes in the gill were not observed; however, CYP1A-like immunoreactivity was detected in the pillar cells of gill lamellae of fish exposed to 67.9 μg/L PAC. Concentration-specific changes in kidney expression of a transmembrane water channel, aquaporin 3, occurred during seawater acclimation, but were resolved with 1 wk of depuration and were not associated with histopathological changes. In conclusion, apart from a robust CYP response in the gill, dilbit exposure did not greatly impact common measures of seawater acclimation, suggesting that significant osmoregulatory dysfunction is unlikely to occur if Atlantic salmon smolts are exposed sub-chronically to dilbit.
       
  • Goodbye and thanks for 2005–2019
    • Abstract: Publication date: Available online 10 January 2020Source: Aquatic ToxicologyAuthor(s): Mikko Nikinmaa
       
 
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