Reproductive toxicity of the endocrine disrupters vinclozolin and bisphenol A in the terrestrial isopod Porcellio scaber (Latreille, 1804) M.F.L. Lemos a,b, * , C.A.M. van Gestel c , A.M.V.M. Soares a a CESAM and Departamento de Biologia – Universidade de Aveiro, 3810-193 Aveiro, Portugal b Instituto Politécnico de Leiria, Escola Superior de Tecnologia do Mar, 2524-909 Peniche, Portugal c VU University Amsterdam, Institute of Ecological Science, NL-1081 HV, Amsterdam, The Netherlands article info Article history: Received 6 July 2009 Received in revised form 21 October 2009 Accepted 27 October 2009 Available online 16 December 2009 Keywords: Ecdysteroids Terrestrial isopods Reproductive allocation Reproduction Systemic toxicity Trade-offs abstract Endocrine Disruptor Compounds (EDCs) have been largely studied concerning their effects on verte- brates. Nevertheless, invertebrates as targets for these chemicals have been neglected and few studies are available. Specifically for edaphic invertebrates, data concerning the effects of EDCs is residual. Influ- ences of EDCs on the reproduction systems of these organisms, with consequences at the population level, are expected but have not been confirmed. This work aimed to study the effects of bisphenol A (BPA) and vinclozolin (Vz) on the reproduction of the terrestrial isopod Porcellio scaber. Isopods were cou- pled and exposed to increasing concentrations of Vz and BPA and the females’ reproductive cycle fol- lowed for 56 d. Both compounds elicited reproductive toxicity. Vz and BPA decreased female reproductive allocation. Vz reduced pregnancy duration; increased the abortion percentage; decreased the number of pregnancies; and decreased the number of juveniles per female while BPA increased abor- tions at the lowest and highest test concentrations. The reproductive endpoints presented in here are indicative of the possible impact that this type of compounds might have on isopod population dynamics, which may eventually lead to population decline. Ó 2009 Elsevier Ltd. All rights reserved. 1. Introduction There are increasing evidences that environmental endocrine disruptor compounds (EDCs) are impacting wildlife populations by interfering with some aspects of endocrine-mediated processes, causing impairments of developmental, reproductive and other hormonally mediated processes (Rodriguez et al., 2007). While for vertebrates significant efforts have been made to study the ef- fects of EDCs, to date there are very few studies on the effects of these compounds on invertebrates, although they constitute the vast majority of organisms of the animal kingdom (deFur et al., 1999). Moreover, chemical signalling systems and their basic mechanisms in the animal kingdom exhibit a considerable degree of conservatism (McLachlan, 2001). Consequently, invertebrate endocrine function should be affected by identical or similar com- pounds as vertebrates (deFur et al., 1999). Terrestrial isopods are widespread saprophytic organisms that carry a key role in the organic matter decomposition in soils. These organisms, beside being recommended for assessing the ecotoxico- logical effects of chemicals in the laboratory (Drobne and Hopkin, 1994), combine the features of continuous growth through a molt- ing regime, sexual reproduction, relative knowledge of endocrinol- ogy and a terrestrial mode of living, making them suitable candidates for sentinel species for EDCs in terrestrial environments (Lemos et al., 2009). Moreover, the isopods’ female reproductive cycle (ovarian maturation and embryogenesis) is an overlapping/ synchronous event along with the molt cycle (Subramoniam, 2000). Therefore, chemicals that interfere with the production or function of molting hormones (ecdysteroids) and interfere with the molt are bound to disrupt reproductive processes (LeBlanc, 2007). In this study, two hormonally active compounds in isopods (Lemos et al., 2009) were investigated. Vinclozolin (Vz) is a fungi- cide widely used in agriculture. It is a proven EDC causing anti- androgenic effects due to two of its metabolites (Anway et al., 2005). In vertebrates it is known to inhibit testosterone induced growth of androgen-dependent tissues (Kang et al., 2004). It in- duces Leydig cell tumors (Kavlock and Cummings, 2005), reduces ejaculated sperm numbers and prostate weight (Monosson et al., 1999), leads to a delayed puberty in exposed rats and demasculini- zation and feminization of male offspring in rats (Gray et al., 1999). Also, one major concern is that Vz causes transgenerational effects 0045-6535/$ - see front matter Ó 2009 Elsevier Ltd. All rights reserved. doi:10.1016/j.chemosphere.2009.10.063 * Corresponding author. Address: CESAM and Departamento de Biologia – Universidade de Aveiro, 3810-193 Aveiro, Portugal. Tel.: +351 234 370 972; fax: +351 234 372 587. E-mail addresses: mlemos@ua.pt (M.F.L. Lemos), kees.van.gestel@falw.vu.nl (C.A.M. van Gestel), asoares@ua.pt (A.M.V.M. Soares). Chemosphere 78 (2010) 907–913 Contents lists available at ScienceDirect Chemosphere journal homepage: www.elsevier.com/locate/chemosphere