小蜒螺（如上图）找到了一种将旅行时间从几年减至几个月的好办法——搭便车。
据美国《科学》杂志在线新闻报道，生活在南太平洋小岛上的16种Neritina aperulata蜗牛会伏在一种体型更大的Nerita pulligera蜗牛的背上，完成其一生一次的旅行——从河流与小溪向天敌更少且藻类更多的目的地前进。这一行为是在强制迁徙过程中搭便车的首个例证。研究人员在4月22日的《生物学快报》网络版上报告了这一发现。（生物谷Bioon.com）
生物谷推荐原始出处：
Biology letters，doi: 10.1098/rsbl.2008.0528，Angus Davison，Markus P Eichhorn
Mating behaviour in Lymnaea stagnalis pond snails is a maternally inherited, lateralized trait
Angus Davison*, Hayley T Frend, Camile Moray, Hannah Wheatley, Laura J Searle and Markus P Eichhorn
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 snail Lymnaea stagnalis is 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 of L. stagnalis is set up early in development, and is a direct consequence of the asymmetry of the entire body.
