title: Pseudoreplication and the usage of biomarkers in ecotoxicological bioassays.
abstract: Pseudoreplication is a widely discussed topic in the scientific community. Its principal critique concerns the lack of independence in flawed experimental designs and the use of inferential statistics to test the hypothesis of such experiments. Thirty years after its appearance, it remains misunderstood by many researchers, including ecotoxicologists. In the present study, we try to clarify some of its concepts by filling in what seems to be a gap in the terminology of manipulative experiments. We propose the term "experimental medium" to refer strictly to the relevant spatial scale of the experiment to preserve the specificity of the experimental and observational units and to display pseudoreplication as a kind of misinterpretation and/or misanalysis of inferential statistics. A classification of the types of experimental designs in ecotoxicology is offered, and the problems in using inferential statistics in suboptimal designs are discussed. We hope to shed some light on such a classic topic for ecotoxicologists. Environ Toxicol Chem 2017;36:2868-2874. © 2017 SETAC.
authors.affiliation: Postgraduate Program in Ecology and Conservation, Federal University of Paraná, Curitiba, Paraná, Brazil.
authors.forename: Flávio H
authors.initials: FH
authors.lastname: Tincani
authors.affiliation: Postgraduate Program in Ecology and Conservation, Federal University of Paraná, Curitiba, Paraná, Brazil.
authors.forename: Gabrieli L
authors.initials: GL
authors.lastname: Galvan
authors.affiliation: Department of Genetics, Federal University of Paraná, Curitiba, Paraná, Brazil.
authors.forename: Antonio E M L
authors.initials: AEML
authors.lastname: Marques
authors.affiliation: Postgraduate Program in Ecology and Conservation, Federal University of Paraná, Curitiba, Paraná, Brazil.
authors.forename: Gustavo S
authors.initials: GS
authors.lastname: Santos
authors.affiliation: Department of Pharmacology, Federal University of Paraná, Curitiba, Paraná, Brazil.
authors.forename: Letícia S
authors.initials: LS
authors.lastname: Pereira
authors.affiliation: Department of Chemistry, Federal University of Paraná, Curitiba, Paraná, Brazil.
authors.forename: Thiago A
authors.initials: TA
authors.lastname: da Silva
authors.affiliation: Postgraduate Program in Ecology and Conservation, Federal University of Paraná, Curitiba, Paraná, Brazil.|Department of Pharmacology, Federal University of Paraná, Curitiba, Paraná, Brazil.
authors.forename: Helena C
authors.initials: HC
authors.lastname: Silva de Assis
authors.affiliation: Department of Chemistry, Federal University of Paraná, Curitiba, Paraná, Brazil.
authors.forename: Ronilson V
authors.initials: RV
authors.lastname: Barbosa
authors.affiliation: Postgraduate Program in Ecology and Conservation, Federal University of Paraná, Curitiba, Paraná, Brazil.|Department of Genetics, Federal University of Paraná, Curitiba, Paraná, Brazil.
authors.forename: Marta M
authors.initials: MM
authors.lastname: Cestari
mesh_terms: D000110:Acetylcholinesterase / Q000378:metabolism; D000818:Animals; D001681:Biological Assay; D015415:Biomarkers / Q000032:analysis* / Q000378:metabolism; D001517:Coleoptera / Q000187:drug effects / Q000378:metabolism; D020552:Comet Assay; D054750:Ecotoxicology; D004912:Erythrocytes / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D008294:Malathion / Q000633:toxicity; D009132:Muscles / Q000201:enzymology; D012107:Research Design; D015027:Zebrafish / Q000502:physiology
chemical_list: D015415:Biomarkers; D000110:Acetylcholinesterase; D008294:Malathion
keywords: Bioassay; Ecotoxicology; Experimental unit; Pseudoreplication; Statistical independence