Fig. 4From: Habitat-specific size structure variations in periwinkle populations (Littorina littorea) caused by biotic factorsMean shell height increment (±SD) of Littorina littorea (initial length of 9.5–12 mm) in a 6 months long cross transplantation experiment on the rocky shore of Helgoland and sedimentary shore near Sylt in 2006. First mentioned site stands for snail origin and second mentioned site indicates location after transformationBack to article page