Ionic composition and osmolality of paddlefish (Polyodon spathula, Acipenseriformes) seminal fluid

Changes in ionic composition as Na+, K+, Ca2+ and Mg2+, osmolality in seminal fluid, percentage of motile spermatozoa and velocity were investigated in response to CPP and different dosage of LHRHa. The lowest velocity of sperm was observed after use CPP treatment. The velocity of spermatozoa, significant main effect of the treatment ( P < 0.0001) and the time of sperm collection ( P < 0.0104) were evaluated. The osmolality of seminal fluid was different between experimental groups of LHRHa (48.0 - 62.7 mOsmol. kg(-1)) and CPP (33.0 - 46.3 mOsmol. kg(-1)) treatments. The osmolality was significantly higher on the first day and one-half, then declined on day three, ranging from 33.0 to 62.7 mOsmol. kg(-1). Analysis of variance showed significant main effects of the treatment ( P < 0.0001) and the time of sperm collection ( P < 0.0002) on the osmolality of seminal fluid. The level of Na+ and K+ ion was different between experimental groups of LHRHa and CPP treatment. The highest concentration of 11.11 mmol. l(-1) was observed at Na+ ion. Then the concentrations declined on the level 1.56, 0.52 and 0.36 mmol. l(-1) for K+, Ca2+ and Mg2+ ions, respectively. There were highly positive correlations between osmolality of seminal fluid and dosage of LHRHa treatment (r = 0.84), velocity of spermatozoa and osmolality of seminal fluid (r = 0.57) and osmolality of seminal fluid and Na+ concentration at seminal fluid ( r = 0.70). Injection with LHRHa increased quality of sperm as velocity of sperm, level of Na+, K+ and osmolality at seminal fluid compared to CPP treatments.