A shockingly high percentage of female sea snails off the coast of Perth, Australia, have been found with a troubling new feature - penises growing from their heads! Researchers say that at one point, 100 percent of the snail species Thais orbita were found with the male appendage, and that the anti-fouling chemical TBT was to blame. As if these thorny new adornments weren't problem enough, it just might determine the fate of the species, and the ecosystem. According to a report from The Australian, the marine snails are suffering from a disorder called 'imposex' and that it is being caused by a chemical used by boatmen until the early 1990s, called TBT. Because the agent remained in the sediment, snails continue to be profoundly affected, with all female snails growing penises from their heads as late as 2005.
It may sound a bit more unusual than it actually is however, since that is where male snails wear their most distinctive appendage naturally - but for a female snail, it´s quite troublesome. Monique Gagnon from Australia´s Curtin University explains:
When that organ is inside the shell, it blocks the release of the eggs and the female becomes sterile. In severe cases, the female cannot reproduce and it will actually kill her, because the egg bag inside the shell will rupture and cause infection.
Gagnon says that if snail populations decline due to this problem, it could have dire consequences for the ecosystem. ¨If this snail was to disappear completely, the predator role will be lost and we can end up with less biodiversity.¨
There is good news, however. It would appear that the harmful presence of TBT in the waters off of West Australia is declining. The most recent survey of marine snails found that only 68 percent of females were growing penises, as opposed to all of them just a few years earlier.
While researchers see this decline in female with penises on their heads as a positive sign for the state of the ecosystem in the waters off of Australia, I´m sure male sea snail are happy to see the trend pass as well.