Ionic control of sperm motility and trials for the improvement of pufferfish (Takifugu alboplumbeus) sperm extenders

Seminal plasma characteristics, such as ionic composition and pH, are important for sperm maturation further motility. In this work, a first batch of experiments evaluated the effect absence several ions (Na+, K+, Mg2+) in artificial seminal plasma, well pH seawater on activation pufferfish (Takifugu alboplumbeus, named before Takifugu niphobles). all experiments, total motility, progressive curvilinear velocity, straight line average path velocity were measured. The Na+, K+ or Mg2+ did not reduce motility comparison with control. contrast, had strong Samples diluted at 6.5 showed high reduction higher pHs (7.5, 8.5 9.5), inhibition was reversible. Where (used medium) concerned, there no significant differences between control (pH 8.2) 6.5, indicating that spermatozoa can swim acidic environments. Finally, nigericin (that make equal intracellular extracellular pH) added, highest found 7.0, which suggested optimal is 7.0. Our second developed to optimize extenders achieve longer preservation under refrigeration, assessing addition concentrations magnesium NaHCO3 other fish species), different pHs. From extender it observed bicarbonate reduced after 7 days incubation, be concluded use 2 mM part composition, combination measured (7.5), seems best option short-medium term storage species.