title: Altered reproductive behaviours in male mosquitofish living downstream from a sewage treatment plant.
abstract: Freshwater environments are common repositories for the discharge of large volumes of domestic and industrial waste, particularly through wastewater effluent. One common group of chemical pollutants present in wastewater are endocrine disrupting chemicals (EDCs), which can induce morphological and behavioural changes in aquatic organisms. The aim of this study was to compare the reproductive behaviour and morphology of a freshwater fish, the mosquitofish (Gambusia holbrooki), collected from two sites (wastewater treatment plant (WWTP) and a putative pristine site). The mosquitofish is a sexually dimorphic livebearer with a coercive mating system. Males inseminate females using their modified anal fin as an intromittent organ. Despite this, females are able to exert some control over the success of male mating attempts by selectively associating with, or avoiding, certain males over others. Using standard laboratory assays of reproductive behaviour, we found that mosquitofish males living in close proximity to WWTP showed increased mating activity compared to those inhabiting a pristine site. More specifically, during behavioural trials in which males were allowed to interact with females separated by a transparent divider, we found that WWTP-males spent more time associating with females. Concordant with this, when males and females were subsequently allowed to interact freely, WWTP-males also spent more time chasing and orienting towards the females. As a result, females from both sites showed more interest towards the WWTP-site males. Male anal fin morphology, however, did not differ between sites. Our study illustrates that lifetime exposure to WWTP-effluents can greatly affect male behaviour. The results underscore the importance of behaviour as a potential tool for investigating unknown contaminants in the environment.
authors.affiliation: School of Biological Sciences, Monash University, Victoria, Australia; Åbo Akademi University, Department of Biosciences, Turku, Finland. Electronic address: minna.saaristo@monash.edu.
authors.forename: Minna
authors.initials: M
authors.lastname: Saaristo
authors.affiliation: Centre for Aquatic Pollution Identification and Management (CAPIM), Department of Zoology, The University of Melbourne, Victoria, Australia. Electronic address: jhmyers@unimelb.edu.au.
authors.forename: Jackie
authors.initials: J
authors.lastname: Myers
authors.affiliation: School of Biological Sciences, Monash University, Victoria, Australia. Electronic address: rowan.jacques.hamilton@gmail.com.
authors.forename: Rowan
authors.initials: R
authors.lastname: Jacques-Hamilton
authors.affiliation: Centre for Aquatic Pollution Identification and Management (CAPIM), School of Chemistry, The University of Melbourne, Victoria, Australia. Electronic address: mayumia@unimelb.edu.au.
authors.forename: Mayumi
authors.initials: M
authors.lastname: Allinson
authors.affiliation: Urban Environment Group, Osaka City Institute for Public Health and Environmental Sciences, Osaka, Japan. Electronic address: yamamoto@iphes.city.osaka.jp.
authors.forename: Atsushi
authors.initials: A
authors.lastname: Yamamoto
authors.affiliation: Centre for Aquatic Pollution Identification and Management (CAPIM), School of Chemistry, The University of Melbourne, Victoria, Australia. Electronic address: gallinson@unimelb.edu.au.
authors.forename: Graeme
authors.initials: G
authors.lastname: Allinson
authors.affiliation: Centre for Aquatic Pollution Identification and Management (CAPIM), Department of Zoology, The University of Melbourne, Victoria, Australia. Electronic address: vpet@unimelb.edu.au.
authors.forename: Vincent
authors.initials: V
authors.lastname: Pettigrove
authors.affiliation: School of Biological Sciences, Monash University, Victoria, Australia. Electronic address: bob.wong@monash.edu.
authors.forename: Bob B M
authors.initials: BB
authors.lastname: Wong
mesh_terms: D000818:Animals; D003532:Cyprinodontiformes / Q000502:physiology*; D005260:Female; D008297:Male; D012098:Reproduction; D012722:Sewage; D012726:Sexual Behavior, Animal / Q000187:drug effects*; D014874:Water Pollutants, Chemical / Q000633:toxicity*
chemical_list: D012722:Sewage; D014874:Water Pollutants, Chemical
keywords: EDCs; Endocrine disrupting chemicals; Mosquitofish; Reproductive behaviour; Sexual selection; Wastewater treatment plant