Imposex in Two Muricid Species (Mollusca: Gastropoda) from the Northeastern Brazilian Coast

Abstract

Imposex is the occurrence of male sexual features in female prosobranch mollusks exposed to organotin compounds. Since imposex has measurable characteristics, it has been used as a bioindication tool for the presence of this kind of pollutants. Thus, this work aimed to monitor organotin pollution over areas under the influence of ten main harbors of Northeastern Brazilian coast. Imposex intensity was measured using the indexes VDSI, RPSI, RPLI and the percentage of imposexed females. At least one sampling site in each studied harbor showed imposex, suggesting a widespread contamination by organotin compounds. However, the observed imposex levels are lower than those obtained by other monitoring works in highly industrialized regions of Europe and Asia, confirming that organotin contamination levels are higher in the most industrialized regions of the world. Approximately 39% of all sampling sites (32 sites) did not show imposexed females, suggesting that this feature does not occur naturally in Stramonita haemastoma and Stramonita rustica.

Assessment of tributyltin contamination based on imposex in Stramonita rustica (Mollusca: Gastropoda) along southern Bahia coast, northeastern Brazil

“…Similar results have been observed worldwide: on the northeastern Brazilian coast, in relation to S. rustica (Castro et al, 2007(Castro et al, , 2008, in the Mediterranean, in relation to Hexaplex trunculus (L.) (Axiak et al, 1995), and in several harbors in Europe and in Halifax harbor, Canada, in relation to Nucella lapillus (L.) (Sousa et al, 2009). Other studies have also confirmed that areas near harbors and marinas are hotspots for TBT pollution (Barroso et al, 2002;Sousa et al, 2005).…”

“…Regarding S. rustica, the data from the present study showed that there was widespread use of TBT in southern Bahia. In studies conducted by Castro et al (2007Castro et al ( , 2008 along the northeastern coast of Brazil using S. rustica and S. haemastoma as bioindicators, it could be seen that the first species was less sensitive than S. haemastoma, i.e., S. rustica showed lower RPL and VDS values at the same collection points. These data, together with possibly relatively low TBT contamination in our study area, may explain the low imposex rates in southern Bahia.…”

Reprodução e potenciais impactos sobre Littorina flava (Neogastropoda: Littorinidae) na Ilha do Mel, Paraná

“…O TBT pode promover o desenvolvimento de um pênis não funcional nas fêmeas, evento a que se denomina de imposex (Garaventa et al, 2006). No Brasil, o monitoramento deste poluente é efetuado predominantemente com o neogastropoda T. haemastoma (Biasi et al, 2010;Castro et al, 2000;2007a;2007b;20012). Em estudos reprodutivos, alterações na proporção sexual (decorrentes de castração das fêmeas) podem indicar influência deste contaminante na reprodução da espécie alvo (Broeck et al, 2009 (Castro et al, 2012) constataram valores de TBT de 52,6ng/g de tecido em T. haemastoma.…”

“…Além disso, as espécies do gênero Littorina podem ser utilizadas para monitorar a contaminação ambiental (Broeck et al;. É certo que metais pesados e/ou compostos orgânicos podem afetar características reprodutivas e fisiológicas de gastrópodes (Castro et al, 2000;2007a;2007b;2012;Broeck et al, 2009;Biasi et al, 2010).…”

Penis Malformations in Leucozonia nassa (Gmelin, 1792) and Leucozoniaocellata (Gmelin, 1791) in a TBT Contaminated Region from Brazil

“…In Brazil, imposex has been studied primarily in Stramonita haemastoma (Castro et al, 2000(Castro et al, , 2007aFernandez et al, 2002; and in Stramonita rustica (Lamarck, 1822) (Camillo et al, 2004;Castro et al, 2004Castro et al, , 2007a. Other species are also being used in biomonitoring programs, such as Thais deltoidea (Costa et al, 2008a), Cymatium parthenopeumparthenopeum (Costa et al, 2008b), Nassarius vibex (Cardoso et al, 2010) and species of the family Fasciolariidae, including Leucozonia nassa and Leucozonia ocellata (Costa et al, 2014).…”