Altered reproductive behaviours in male mosquitofish living downstream from a sewage treatment plant

• Published in: Aquatic toxicology Vol. 149; pp. 58 - 64
• Main Authors: Saaristo, Minna, Myers, Jackie, Jacques-Hamilton, Rowan, Allinson, Mayumi, Yamamoto, Atsushi, Allinson, Graeme, Pettigrove, Vincent, Wong, Bob B.M.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01.04.2014; Elsevier
• Subjects: Agnatha. Pisces; Animal, plant and microbial ecology; Animals; Applied ecology; Biological and medical sciences; Culicidae; Cyprinodontiformes - physiology; Ecotoxicology, biological effects of pollution; EDCs; Effects of pollution and side effects of pesticides on vertebrates; Endocrine disrupting chemicals; Female; Freshwater; Fundamental and applied biological sciences. Psychology; Gambusia holbrooki; Male; Mosquitofish; Reproduction; Reproductive behaviour; Sewage; Sexual Behavior, Animal - drug effects; Sexual selection; Wastewater treatment plant; Water Pollutants, Chemical - toxicity; Reproductive behaviour; Wastewater treatment plant; Sexual selection; Mosquitofish; Endocrine disrupting chemicals; EDCs; Mimetic hormone; Toxicity; Estrogen; Male; Endocrine disruptor; Breeding behavior; Freshwater environment; Vertebrata; Pisces; Waste water discharge; Gambusia affinis
• DOI: 10.1016/j.aquatox.2014.02.001
• ISSN: 0166-445X

•We examined the effects of aquatic contaminants on wild fish populations.•We tested mosquitofish from a wastewater treatment plant (WWTP) and a pristine site.•We found that males living near the WWTP showed increased mating activity.•Hence, females from both sites showed more interest towards the WWTP-site males.•Behaviour is therefore a useful biomarker of environmental contamination. 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.