Morphological variation in Lacuna parva (Gastropoda: Littorinidae) from different European populations

Abstract.

Shells of the littorinid gastropod Lacuna parva were compared from 23 European localities and postglacial deposits in Sweden. The shells from the recent and the postglacial populations are similar with the exception of the recent population from Ellekilde Hage, Øresund, Denmark. Shells from Ellekilde Hage are different in having especially well developed whorls and only one colour morph. Differences in life-cycle and radula morphometrics further distinguish the Ellekilde Hage population from populations from the Isle of Wight, UK, and Roscoff, France. No striking differences in penial morphology were observed between the populations. It is suggested that low salinity and subtidal occurrence might be the causative agents of the conchological differences exhibited by the Øresund population.