Landlocked Fall Chinook Salmon Sperm Motility after Short Term Milt Storage
Sara E. Reese 1, Anthony J. Long 1, Hilary A. Meyer 1, Michael E. Barnes 2*
During salmonid spawning, milt is frequently stored on ice prior to use. This study evaluated landlocked fall Chinook salmon (Oncorhynchus tshawytscha) sperm motility during the first two hours of milt storage. Motility duration was recorded immediately after stripping and every 20 minutes for two hours thereafter from the milt of eight males on two spawning days. Sperm remained motile for the entire two hour period on both days, although the duration of motility was significantly greater on the first spawning day in comparison to the second day one week later. On the first spawning day, sperm motility duration was over 40 seconds throughout the entire two hour period, and did not significantly differ among sampling times. On the second spawning day, motility duration significantly declined after 80 minutes of milt storage on ice to a mean of approximately 30 seconds, although this decline was likely not severe enough to impact salmon sperm fertilizing capabilities. These results indicate that milt can be successfully stored on ice for up to two hours post-stripping with only minimal impacts on sperm motility.