Here’s an odd story coming out of an Australia paper, female marine snails living off the coast of Perth were found to be growing penises on their heads. Of course, this growing of secondary male sex organs (called imposex) is not brought on by natural circumstances. Instead, the snails were exposed to TBT, or tributyltin, which is commonly found in marine paint with anti-fouling properties. These paints are designed to prevent organisms like barnacles from settling on boat hulls. The fouling organisms damage boats and increase their drag in the water, thus making them slower. Even after TBT contamination had declined at the sites being studied, 100% of the female snails were still showing this odd deformity. The TBT is thought to still be present in the sediment, which continues to cause the imposex condition. This condition could cause the snails to stop reproducing. And given the fact that all of the snails at certain sites showed this characteristic, entire populations could be at risk of extinction.