Imposex in Nucella lapillus and intersex in Littorina littorea: interspecific comparison of two TBT-induced effects and their geographical uniformity

Abstract

Two different tributyltin (TBT)-induced virilisation phenomena in prosobranch snails -intersex in Littorina littoreaand imposex in Nucella lapillus -are compared in order to facilitate their simultaneous use in geographical large scale effect monitoring surveys. Imposex in dogwhelks is a more sensitive biomarker and should be used in areas that are only slightly or moderately contaminated with TBT (ambient TBT concentrations < 2.0 ng as Sn 1-1). The assessment of intersex intensities in periwinkle populations has considerable advantages in areas with higher TBT concentrations and should be used also wherever dogwhelks are absent irrespective of the TBT exposure level. The intersex index (ISI) and vas deferens sequence (VDS) index are proposed as the most suited parameters for effect monitoring purposes. The geographical uniformity of intersex and imposex is analysed and proven for the coasts of Ireland, France, and Germany. A relative loss of TBT sensitivity in females can be found, but to a varying extent in both species. The implications of this result for biological TBT effect monitoring programmes are discussed in light of the fact that intersex and imposex have both been found to be irreversible. Because it is the objective of these programmes to assess current TBT contaminations and resulting biological effects, only relatively young specimens should be considered in the sampling strategy.

Effects of endocrine modulating substances on reproduction in the hermaphroditic snail Lymnaea stagnalis L

“…In contrast, recent studies with nonhermaphroditic prosobranch snails demonstrated that exposure to very low ambient concentrations of organotin compounds resulted in a masculinisation and sterilisation and therefore in reproductive failure in the female snails (Oehlmann et al, 1998;Schulte-Oehlmann et al, 1997). The phenomenon of intersex and imposex (pseudohermaphrodism) presented by these highly sensitive species Minchin et al, 1997;, may be a species or even sub-class specific effect.…”

Occurrence of imposex in Thais haemastoma: possible evidence of environmental contamination derived from organotin compounds in Rio de Janeiro and Fortaleza, Brazil

“…VDSI is the only index that responds effectively over a broad range of imposex. It is useful in assessing the reproductive capacity of the studied population; populations with a mean VDSI above IV are comprised of sterile females, and show reduced reprodutive capacity (Gibbs & Brian, 1994;Oehlmann et al, 1996Oehlmann et al, , 1998Stroben et al, 1995). VDSI was obtained through two different approaches: (1) by using the scale of Gibbs (Gibbs & Bryan, 1987), and (2) by using a modified scale of seven levels of imposex, developed by Fernandez et al (1998).…”

Widespread endocrine activity in river sediments in Hesse, Germany, assessed by a combination of in vitro and in vivo bioassays

“…Two of the best known cases of endocrine disruption in wildlife are (i) the formation of imposex in female prosobranch snails in tributyltin (TBT) polluted areas (Oehlmann et al 1998;Santos et al 2005;Wirzinger et al 2007) and (ii) the demasculinization of male or "super-feminization" of female alligators in Lake Apopka in Florida, USA, associated with a pesticide spill as well as several decades of extensive agricultural activity around the lake and related pesticide and nutrient runoff (Guillette et al 1994).…”