The pattern of geographical and altitudinal variation in the land snail Albinaria idaea from Crete (Gastropoda: Clausiliidae)

Abstract

Certain morphological characters in the Mediterranean land snail genus Albinaria are believed not to be closely related to ecological conditions. Recently this view has been challenged by a study on A. idaea from central Crete (Greece) claiming that shell characters such as rib density, apertural lamella sizes and shell size parameters depend on ecological variables related to altitude. The present study suggests that variation in apertural lamellae, shell size parameters and shell shape were not related to altitude. Neither were they closely related to expected temperature gradients, nor toDrilus beetle predation pressure, nor to vegetational cover (forests/open land). The rib density was the only factor responding to altitude, but after accounting for altitude, altitude-independent regional variation was also of importance. The correlation with altitude was possibly caused by a response to temperature gradients.