Effects of Exposure to WwTW Effluents over Two Generations on Sexual Development and Breeding in Roach <i>Rutilus rutilus</i>

Exposure to environmental estrogens in wastewater treatment works (WwTW) effluents induces feminized responses in male fish, including the development of eggs in male testes. However, the impacts on the offspring of exposed fish are not well understood. In this study, we examined whether roach (Rutilus rutilus) from mothers that had been exposed to an undiluted WwTW effluent from early life to sexual maturity had altered susceptibility to gonadal feminization and an impaired capacity to reproduce. For males from both WwTW effluent exposed mothers and dilution water exposed mothers, effluent exposure for up to 3 years and 9 months induced feminized male gonads, although the intersex condition was relatively mild. There was no difference in the severity of gonadal feminization in roach derived from either WwTW effluent exposed or dilution water exposed mothers. Furthermore, a breeding study revealed that roach with effluent-exposed mothers reproduced with an equal success as roach with mothers exposed to clean water. Roach exposed to the effluent for 3 years in this study were able to reproduce successfully. Our findings provide no evidence for impacts of WwTW effluent exposure on reproduction or gonadal disruption in roach down the female germ line and add to existing evidence that male roach with a mild intersex condition are able to breed competitively

Figure_3_ExperimentI

Data collected in the laboratory, for the number of eggs spawned per female, over the 10 day study period of Experiment I. Each spawning group (each tank) contained 1 female and 2 males (either all inbred fish or all outbred as indicated in table). Low dose refers to previous exposure to 5 ug/L clotrimazole (nominal) as detailed in manuscript

Figure_5_Tank1(A21A)

Paternity analysis for Tank 1 (A21A). Study Day indicates the day on which each embryo analysed was spawned. The first 3 rows in the table are the parent fish and below that are the 20 selected offspring. The microsatellite loci used for analysis are listed along the top of the table and corresponding allelles are detailed below

Figure_5_Tank17(B18B)

Paternity analysis for Tank 17 (B18B). Study Day indicates the day on which each embryo analysed was spawned. The first 3 rows in the table are the parent fish and below that are the 20 selected offspring. The microsatellite loci used for analysis are listed along the top of the table and corresponding allelles are detailed below

Figure_5_Tank18(B19A)

Paternity analysis for Tank 18 (B19A). Study Day indicates the day on which each embryo analysed was spawned. The first 3 rows in the table are the parent fish and below that are the 20 selected offspring. The microsatellite loci used for analysis are listed along the top of the table and corresponding allelles are detailed below

Figure_5_Tank3(A23C)

Paternity analysis for Tank 3 (A23C). Study Day indicates the day on which each embryo analysed was spawned. The first 3 rows in the table are the parent fish and below that are the 20 selected offspring. The microsatellite loci used for analysis are listed along the top of the table and corresponding allelles are detailed below

Figure_5_Tank9(A26B)

Paternity analysis for Tank 9 (A26B). Study Day indicates the day on which each embryo analysed was spawned. The first 3 rows in the table are the parent fish and below that are the 20 selected offspring. The microsatellite loci used for analysis are listed along the top of the table and corresponding allelles are detailed below

Figure_5_Tank14(B16B)

Paternity analysis for Tank 14 (B16B). Study Day indicates the day on which each embryo analysed was spawned. The first 3 rows in the table are the parent fish and below that are the 20 selected offspring. The microsatellite loci used for analysis are listed along the top of the table and corresponding allelles are detailed below

Figure_3_ExperimentII

Data collected in the laboratory, for the number of eggs spawned per female, over the 10 day study period of Experiment II. Each spawning group (each tank) contained 1 female (either inbred or outbred, as indicated in table) and 2 males (one inbred and one outbred). Low dose refers to previous exposure to 5 ug/L clotrimazole (nominal) as detailed in manuscript

Figure_6_11KT

Data shows amount of plasma 11 ketotestosterone (ng/mL) measured in male fish, either inbred or outbred, or from the control or exposed treatment group, as indicated. The proportion of offspring sired by each male fish is also indicated (from spawning groups containing an outbred female only, as described in the associated manuscript)