Up until 2008, the chemical TBT was used in ship’s anti-fouling paint, which caused female snails to grow penises and ultimately explode because they couldn’t shed their eggs. – WTF Fun Facts
Source: http://blogs.discovermagazine.com/d-brief/2014/01/15/female-sea-snails-no-longer-growing-penises-thanks-to-ban-on-toxic-chemical/#.XRiq_I97mUl
