The summary of the geometric morphometric analysis
showing the centroid/mean morphology and variation in the
dorsal and ventral/apertural shell shape pattern of different P.
canaliculata populations as produced by the relative warps
(RW) is shown in Fig. 3 and described in Table I. Projections
on the left side of the histogram are considered to be
variations in shell shape expected as negative deviations of
the mean in the axis of the relative warps. Then, on the right
side are variations in shell shape expected as positive
deviations of the mean in the axis of the relative warps. The
topmost figure is the mean shape of the samples. Differences
between sexes and geographical regions are based on the