THE SNAIL’S LOVE DART

When we talk about competition for mates, we often think of behaviors involving tense fights or flamboyant displays of traits that signal quality. However, sometimes the competition continues even after mating, as the sperm must outcompete sperm from other mates. 

In land snails of the families Helicidae and Ariophantidae, this post-copulatory competition involves the injection of a calcium-based “love dart”.  These snails are simultaneous hermaphrodites, so during mating, both partners can act as male and female, leading to …