Table 2.

Parameters measured in the software.

Parameter	Description
Area	A; the two-dimensional area of the nucleus
Perimeter	P; the length of the nuclear perimeter
Max feret diameter	the maximum caliper diameter across the nucleus
Min diameter	the shortest caliper diameter through the center of mass of the nucleus
Variability	√(((∑(d²))/L); the square root of the sum-of-squares difference (d) at each index between the nuclear profile and the dataset median profile, after normalization to a fixed length (L)
Ellipticity	H/W; the height (H) divided by width (W) of the nuclear bounding box when the nucleus is vertically oriented
Circularity	4πA/P²; the closeness of the nucleus to a circle, between 0 and 1, where 1 is a perfect circle.
Bounding width	W; the width of the bounding rectangle of the vertically oriented nucleus
Bounding height	H; the height of the bounding rectangle of the vertically oriented nucleus
Angle between reference points	the angle between the tip, the centre of mass, and the caudal reference point (defined as the point of greatest curvature at the rear of the sperm head)
Length of hook [rodent sperm only]	the distance from the vertical alignment region to the x-edge of the bounding rectangle on the hook side (Figure 1D)
Width of body [rodent sperm only]	the distance from the vertical region to the x-edge of the bounding rectangle on the body side (Figure 1D)
Segment lengths	the length of each segment along the perimeter of the nucleus