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Androgynous Snails

October 20, 2010

Females of one species of marine snail conceal their gender to avoid excessive mating.


Androgynous snails. I’m Bob Hirshon and this is Science Update.

To fend off relentless sexual advances, some female sea snails actually hide their gender. This according to researchers at the University of Gothenburg in Sweden. Marine ecologist Kerstin Johannesson explains that male snails find females by tracking feminine chemicals in their mucus trails. But in one kind of periwinkle snail, the females confuse the males by leaving gender-neutral trails.

KERSTIN JOHANNESSON (University of Gothenburg, Sweden):
That’s of course a problem for them, so they quite often end up trying to mate other males.

Johannesson notes that this species lives in dense communities, and mates once or twice a day all year round. And every time they mate, they’re exposed to predators. She suspects that if the females didn’t keep a low profile, they’d be approached far more often, and incur more risk without any biological benefit. I’m Bob Hirshon, for AAAS, the science society.