Please cite this article in press as: M.P. Sárria, et al., Estrogenic chemical effects are independent from the degree of sex role reversal in pipefish, J. Hazard. Mater. (2013), http://dx.doi.org/10.1016/j.jhazmat.2013.10.043 ARTICLE IN PRESS G Model HAZMAT-15493; No. of Pages 8 Journal of Hazardous Materials xxx (2013) xxx–xxx Contents lists available at ScienceDirect Journal of Hazardous Materials jou rn al hom epage: www.elsevier.com/locate/jhazmat Estrogenic chemical effects are independent from the degree of sex role reversal in pipefish Marisa P. Sárria a,b , Miguel M. Santos a,b , L. Filipe C. Castro a , Natividade M. Vieira a,b , Nuno M. Monteiro c,d,∗ a CIMAR/CIIMAR - Interdisciplinary Centre of Marine and Environmental Research, Universityof Porto, Rua dos Bragas 177, 4050-123 Porto, Portugal b FCUP - Departamento de Biologia, Faculdade de Ciências da Universidade doPorto, Rua do Campo Alegre, 4169-007 Porto, Portugal c Centro de Investigac ¸ ão em Biodiversidade e Recursos Genéticos (CIBIO), Campus Agrário de Vairão, R. Padre Armando Quintas, 4485-661 Vairão, Portugal d CEBIMED, Faculdade de Ciências da Saúde, Universidade Fernando Pessoa, Rua Carlos da Maia, 296, 4200-150 Porto, Portugal h i g h l i g h t s • Courtship behaviour resists EE 2 exposure at environmentally relevant concentrations. • EE 2 effects are largely independent from the degree of sex role reversal. • EE 2 affects egg volume and induces vitellogenin expression in males. • Higher EE 2 concentrations cause a cessation of pregnancies in pipefish. • Syngnathids usually inhabit coastal areas where oestrogenic contamination is higher. a r t i c l e i n f o Article history: Received 27 August 2013 Received in revised form 16 October 2013 Accepted 19 October 2013 Available online xxx Keywords: Ethinylestradiol Reproductive behaviour Endocrine disruption Vitellogenin Syngnathidae a b s t r a c t Endocrine disrupting chemicals (EDCs) have been reported to disturb several ecological relevant end- points. Surprisingly, EDC-induced effects on fish sexual behaviour have been poorly studied despite the fact that even subtle alterations might contribute to a disruption of sexual interactions, thus negatively impacting reproduction. As the few assessments on sexual behaviour have been conducted in species with orthodox sex roles, it might be argued that sex-role reversed species might provide a potentially complementary system to further explore the effects of EDCs on reproduction. In the present study, two pipefish species with distinct degrees of sex-role reversal were selected to further elucidate the impact of chronic EE 2 exposure on sexual behaviour and reproduction-related endpoints. The obtained results indicate that, independently of the degree of sex role reversal, courtship behaviour seems to resist oestrogenic chemical exposure. However, exposure to environmentally relevant EE 2 levels did induce a complete absence of pregnancies at 18 ng/L. Even though pregnancies were observed at intermediate concentrations, the percentage of non-transferred or misplaced oocytes increased and a dose-dependent decrease of oocyte volume was observed. Imbalances in the oogenesis process, induction of vitellogenin in males and the absence of pregnancies highlight that environmental relevant concentrations of EE 2 have the potential to negatively affect pipefish populations, most of them inhabiting coastal areas where oestrogenic contamination is more prevalent. © 2013 Elsevier B.V. All rights reserved. 1. Introduction There is now evidence that a group of environmental pollutants commonly designated as endocrine disrupting chemicals (EDCs) are able to impact reproduction in wild fish populations. The effects reported include abnormal gonad structure and differentiation, ∗ Corresponding author at: Centro de Investigac ¸ ão em Biodiversidade e Recursos Genéticos (CIBIO), Campus Agrário de Vairão, R. Padre Armando Quintas, 4485-661 Vairão, Portugal. Tel.: +351 252660411; fax: +351 252661780. E-mail address: nmonteir@fc.up.pt (N.M. Monteiro). intersexuality and sex reversal, decreased fertility and fecundity, and male expression of egg yolk proteins [1]. It has also been shown that EDCs are able to modulate behaviour. Variation in aggression levels, spatial distribution, susceptibility to predation, anxiety and alterations to normal shoaling behaviours have all been recently associated with EDC exposure e.g. [2–5]. As a result, behaviour- based approaches have been highlighted as reliable proxies for the detection of the toxic effects of several EDCs [4,6,7]. Yet, taking into account that the action of endocrine disruptors is especially promi- nent on reproduction-related parameters, EDC-induced effects on fish sexual behaviour have been poorly explored and still weakly understood e.g. [8–11]. 0304-3894/$ – see front matter © 2013 Elsevier B.V. All rights reserved. http://dx.doi.org/10.1016/j.jhazmat.2013.10.043