Correlational sperm motility analysis: wild rodent progressive sperm motility as a potentially improved reproduction-assessment parameter in mammals.

Progressive sperm motility, describing the directed or linear movement of sperm, is infrequently reported in reproductive studies conducted with rodents. This is a curious circumstance given that progressive motility can be easily reported with current computer-assisted sperm-analysis equipment, and because progressively motile sperm seemingly display a greater likelihood of fertilizing ova than do sperm that move in a random or undefined pattern. This study presents a comparison of the routinely reported total motility (i.e., the percentage of moving sperm cells in a sample) and the progressive motility of sperm from rodents captured at soil-contaminated sites and at habitat-matched noncontaminated reference locations. Progressive motility’s trending with total motility at all areas, in terms of direction of shift, magnitude of change, and degree of correlation, was extremely high. Based on these results and in the interest of assisting ecological health assessments at contaminated sites, it would seem prudent to conduct the empirical research to determine progressive sperm motility’s threshold-for-effect, which may be lower than that for total motility.