title: Copper-driven avoidance and mortality in temperate and tropical tadpoles.
abstract: Amphibians have experienced an accentuated population decline in the whole world due to many factors, one of them being anthropogenic contamination. The present study aimed to assess the potential effect of copper, as a worldwide and reference contaminant, on the immediate decline of exposed population due to avoidance and mortality responses in tadpoles of three species of amphibians across climatic zones: a South American species, Leptodactylus latrans, a North American species, Lithobates catesbeianus, and a European species, Pelophylax perezi. A non-forced exposure system with a copper gradient along seven compartments through which organisms could freely move was used to assess the ability of tadpoles to detect and avoid copper contamination. All species were able to avoid copper at a concentration as low as 100 μg L(-1). At the lowest (sublethal) concentrations (up to 200 μg L(-1)) avoidance played an exclusive role for the population decline, whereas at the highest concentrations (> 450 μg L(-1)) mortality was the response determining population decline. The median concentrations causing exposed population immediate decline were 93, 106 and 180 μg L(-1) for Le. latrans, Li. catesbeianus and P. perezi, respectively. Contaminants might, therefore, act as environmental disruptors both by generating low-quality habitats and by triggering avoidance of tadpoles, which could be an important response contributing to dispersion patterns, susceptibility to future stressors and decline of amphibian populations (together with mortality).
authors.affiliation: IMAR-Instituto do Mar, Department of Life Sciences, University of Coimbra, Apartado 3046, 3001-401 Coimbra, Portugal. Electronic address: cristiano.araujo@icman.csic.es.
authors.forename: Cristiano V M
authors.initials: CV
authors.lastname: Araújo
authors.affiliation: IMAR-Instituto do Mar, Department of Life Sciences, University of Coimbra, Apartado 3046, 3001-401 Coimbra, Portugal.
authors.forename: Cândida
authors.initials: C
authors.lastname: Shinn
authors.affiliation: IMAR-Instituto do Mar, Department of Life Sciences, University of Coimbra, Apartado 3046, 3001-401 Coimbra, Portugal.
authors.forename: Matilde
authors.initials: M
authors.lastname: Moreira-Santos
authors.affiliation: Department of Biology & CESAM, University of Aveiro, Campus de Santiago, 3810-193 Aveiro, Portugal.
authors.forename: Isabel
authors.initials: I
authors.lastname: Lopes
authors.affiliation: NEEA-Núcleo de Estudos em Ecossistemas Aquáticos, CRHEA, USP, Universidade de São Paulo, São Paulo, Brazil.
authors.forename: Evaldo L G
authors.initials: EL
authors.lastname: Espíndola
authors.affiliation: IMAR-Instituto do Mar, Department of Life Sciences, University of Coimbra, Apartado 3046, 3001-401 Coimbra, Portugal.
authors.forename: Rui
authors.initials: R
authors.lastname: Ribeiro
mesh_terms: D000818:Animals; D001001:Anura / Q000502:physiology*; D003300:Copper / Q000633:toxicity*; D017753:Ecosystem; D007814:Larva / Q000187:drug effects; D007928:Lethal Dose 50; D016019:Survival Analysis; D014874:Water Pollutants, Chemical / Q000633:toxicity*
chemical_list: D014874:Water Pollutants, Chemical; D003300:Copper
keywords: Amphibian population decline; Anuran larvae; Avoidance; Contamination; Environmental disruption