Factors affecting the activation and duration of motility of the spermatozoa of the summer whiting (Sillago ciliata)

Semen was manually stripped from males and motility was highest if the semen was stored on ice and diluted with activating media also kept on ice. Activation of the sperm was caused by media with an osmolarity greater than 300 mOsM and ionic solutions were superior to non-ionic solutions. Solutions of 600 mOsM with ratios of Na:K of 2:1 or more resulted in a significant increase in the rate of increase of the curve described by the equation y=347.7+39.7X+10.6X where X=log [Na] K] and y=duration of motility. Motility was enhanced by levels of magnesium and calcium ions at 675 mOsM and 120 mOsM, respectively. The addition of metabolizable energy sources (Na lactate and Na pyruvate) also improved the duration of motility