Migrational orientation in two species of littoral gastropods (Littorina angulifera and Nerita senegalensis)

Littorina angulifera (Lamark) and Nerita senegalensis Gmelin, both intertidal gastropods, appear to have a preference for specific levels of the shore. In some experiments conducted both in the laboratory and in the field, displaced snails exhibited a general homing behaviour when displaced upshore or downshore. Cues involved in this migrational behaviour have not clearly been identified.