Mating behaviour inLymnaea stagnalispond snails is a maternally inherited, lateralized trait

Abstract

Lateralization of the brain has traditionally been considered a specialization that is confined to the vertebrates, but recent studies have revealed that a range of invertebrates also have a brain that is structurally asymmetric and/or each side performs a different set of functions. Here, we show that the precopulatory mating behaviour of the pond snailLymnaea stagnalisis lateralized. We present evidence that the asymmetry of the behaviour corresponds to the sinistral or dextral shell coil, or chirality, of the snail, and is apparently also controlled by a maternal effect locus. As sinistral snails also tend to have mirror image brains, these findings suggest that the lateralized sexual behaviour ofL. stagnalisis set up early in development, and is a direct consequence of the asymmetry of the entire body.