title: Copper interacts with nonylphenol to cancel the effect of nonylphenol on fish chemosensory behaviour.
abstract: The majority of ecotoxicological studies have been concerned with responses of organisms to a single contaminant. While this approach remains valid, the challenge now is to understand the way in which multiple contaminants and stressors interact to produce effects in study organisms. Here we take an integrated biological and physico-chemical approach to understand the effects of 4-nonylphenol and copper on fish (white perch, Morone americana) chemosensory behaviour. We show that a one hour exposure to 2 μg L(-1) nonylphenol removes chemosensory attraction to conspecific chemical cues, while exposure to 5 μg L(-1) copper for one hour had no significant effect on the fish's attraction to these cues. Further, we show that simultaneous exposure to both contaminants at the stated dosage and for the same duration has no significant effect on the chemosensory attraction of white perch to conspecific chemical cues suggesting that copper mediates the effect of nonylphenol on fish in this respect. Physico-chemical data show that copper ions bind to nonylphenol in water, providing a mechanistic explanation for this change in the effect of nonylphenol. Furthermore, the finding that the copper ions bind to the lone pair of O on the nonylphenol molecule offers the tantalising possibility that it is this region of the nonylphenol molecule that plays the key role in disrupting fish chemical communication.
authors.affiliation: School of Biological Sciences, University of Sydney, Sydney, NSW, Australia. Electronic address: ashley.ward@sydney.edu.au.
authors.forename: Ashley J W
authors.initials: AJ
authors.lastname: Ward
authors.forename: Maria
authors.initials: M
authors.lastname: Thistle
authors.forename: Khashayar
authors.initials: K
authors.lastname: Ghandi
authors.forename: Suzanne
authors.initials: S
authors.lastname: Currie
mesh_terms: D000818:Animals; D001492:Bass / Q000502:physiology*; D003300:Copper / Q000494:pharmacology*; D004347:Drug Interactions; D010636:Phenols / Q000633:toxicity*; D012677:Sensation / Q000187:drug effects*; D014874:Water Pollutants, Chemical / Q000633:toxicity*
chemical_list: D010636:Phenols; D014874:Water Pollutants, Chemical; D003300:Copper; C041594:4-nonylphenol
keywords: Chemical ecology; Ecotoxicology; Info-disruption; Shoaling; Social attraction; Sociality