Carapace asymmetries in crabs

Abstract Through the geometric morphometric approach of the landmark-based method applied on adult right-handed specimens of Carcinus aestuarii, Liocarcinus depurator and Potamon fluviatile, statistical analyses showed significant outcomes for fluctuating asymmetry in the three studied species, and directional asymmetry only in P. fluviatile (that showed a less convex carapace shape on the right side, where larger chela occurred). Although these findings may be correlated to some environmental constraints, such as soil composition, refuge occurrence and predatory pressure, also other interpretations may be proposed.