“…Studies on the morphological variations of target species can reveal the dynamics of populations and such information can be used to design management strategies (Orensanz et al, 2005). As one of the solid evaluation parameters, morphological variation has been widely used in population studies (Murta, 2000;Tzeng et al, 2001;Chen et al, 2010), stock discrimination (Cadrin et al, 2005;Turan et al, 2006;Murta et al, 2008) and bio-geographical evaluation (Von et al, 2005). In molluscs, shell shape variation has been reported to distinguish species of similar shape (Innes and Bates, 1999;Aguirre et al, 2006;Rufino et al, 2006;Costa et al, 2008Costa et al, , 2010 or to analyse intra-specific variation along a wide geographical range (Palmer et al, 2004;Krapivka et al, 2007;Marquez et al, 2010).…”