During the course of a study on the population structure of C.maenas
we sampled abundant carapaces of the species on the Atlantic coast off
Patagonia. Since we were able to measure the width of carapaces, a
standard measure of crab size, these structures allowed us to obtain
SFDs. However, in order to obtain sex-specific SFDs we required a
method to classify carapaces by sex. Therefore we established the
following objectives for the present study: 1) to determine if carapaces
from C. maenas are sexually dimorphic, and 2) if shape differences of
these structures can be distinguished by simple observation.