First evaluation of imposex in Stramonita brasiliensis (Claremont and Reid, 2011) (Caenogastropoda: Muricidae) from Brazil’s Legal Amazon

Imposex is is a well-documented deleterious effect caused by tributyltin (TBT) in females of hundreds of Caenogastropoda species and it is a well-established way of predicting BTs occurrence in marine systems. This study presents the very first information on the presence and distribution of imposex in Stramonita brasiliensis (Claremont and Reid, 2011) in the Brazilian Legal Amazon, within a Ramsar site, during a 6-year appraisal after the TBT global ban in 2008 (2012–2017). Imposex was evidenced in six out of the seven sampling sites, with 39.7% of the total affected females, most of them showing VDSI <1. The temporal appraisal allowed the identification of the introduction of new sources of TBT in some sites, as well as populational recovery in other sampling points. In addition, the dilution effect present in São Marcos Bay was also likely to play an important role in the imposex distribution.