In June of 2007, we sampled life specimens of C. maenas on the
intertidal zone of San Jorge Gulf, eastern Patagonia (45°–47°S,
Argentina) using collapsible baited traps. Crabs were sexed based
on the observation of abdomen morphology and internal reproductive
organs, and carapace width (CW) was measured between the distal
ends of the posterior antero-lateral spines of males (N=50, range:
38.0–78.7 mm CW) and females (N=50, range: 41.9–60.3 mm CW).
Then, carapaces were dissected, thoroughly cleaned, dried, numbered,
and photographed with a SONY digital camera, the crab's anterior
margin facing the camera lens. The outline configuration (Fig. 1) was
defined closing the dorsal contour of the carapace with a straight line
joining the tips of the fifth antero-lateral spines. As with most twodimensional
data, the final outline corresponded to an orthogonal
projection in a single plane of elements that originally may be located
in different planes.