Spermatozoa motility in the Persian sturgeon, Acipenser persicus: effects of pH, dilution rate, ions and osmolality

Abstract

Sperm motility is a prerequisite factor determining semen quality and fertilizing capacity. The effects of environmental factors including pH, cations and osmolality as well as the role of dilution rate on sperm motility parameters in Acipenser persicus were studied. The best pH and dilution rate for activation of spermatozoa were pH 8.0 and dilution ratio 1:50. Ionic factors can stimulate the initiation of sperm activation. The maximum percentage of motile sperm and total duration of sperm motility were observed in solutions containing 25 mM NaCl, 0.2 mM KCl, 3 mM CaSO 4 , 10 mM MgSO 4 and sucrose with an osmolality of 50 mosmol kg 21. The present study provides us with some basic knowledge about sturgeon spermatozoa biosensitivity to ionic and osmolality effects. A sensitivity of A. persicus sperm was observed after induction of activation of sperm motility in solution containing cations or sucrose with high osmolality. Concentrations more than 50 mM Na 1 , more than 1 mM K 1 , more than 3 mM Ca 21 and more than 10 mM Mg 21 had negative effects on sperm motility. Also, osmolality more than 100 mosmol kg 21 had an inhibitory effect. It is clear that ions and osmolality stimulate the motility of spermatozoa by changes in the properties of the plasma membrane including its potential and its ionic conductance. The inhibitory role of high osmolality of the swimming medium (more than 100 mosmol kg 21 ) and insufficient osmolality of the seminal plasma to inhibit semen motility suggested that osmolality is not the principal factor preventing sperm motility in seminal fluid but that K 1 is a major inhibitory factor of sperm motility in seminal plasma.

Changes of sperm quality parameters in Caspian roach (Rutilus rutilus caspicus) during spawning migration

“…In fish, several factors have been reported that regulate the composition of seminal plasma (Ciereszko, 2008;Alavi et al, 2008b). It has already been shown in the literature that there are several correlations between seminal plasma composition and sperm motility in some species: Salmo salar (Hwang and Idler, 1969), Cyprinus carpio (Kruger et al, 1984), rainbow trout (Lahnsteiner et al, 1998), Persian sturgeon, Acipenser persicus (Alavi et al, 2004), and Oncorhynchus tshawytscha (Rosengrave et al, 2009). Lahnsteiner et al (1996) reported a correlation between sperm motility and seminal plasma composition in bleak Alburnus alburnus, a cyprinid, and suggested that this correlation might indicate which components of the seminal plasma influence sperm motility.…”

Relationships between selected sperm characteristics and fertilisation success in the beluga sturgeon, Huso huso (Linnaeus, 1758)

“…The pH of the activation medium has been identified as a major factor affecting the motility and velocity of fish sperm (Stoss 1983;Alavi and Cosson 2005), which subsequently influences sperm fertility (Billard et al 1995;Linhart et al 2006). In sturgeon, the optimal pH for sperm motility has been reported as pH 8-9 (Gallis et al 1991;Cosson and Linhart 1996;Ingermann et al 2002;Alavi et al 2004). In white sturgeon, A. transmontanus, sperm pre-incubated at pH 8.2 or higher showed higher motility following transfer into water as a swimming medium, but motility decreased or ceased when sperm were pre-incubated at pH 7.5 or lower (Ingermann et al 2002).…”

“…Several published studies have analysed sperm quality and its relationship to reproductive success in a variety of sturgeon species, such as paddlefish, Polyodon spathula Cosson and Linhart 1996); white sturgeon, Acipenser transmontanus (Ingermann et al 2002); Siberian sturgeon, A. baeri (Gallis et al 1991); and Persian sturgeon, A. persicus (Alavi et al 2004;Aramli et al 2013a;Dadras et al 2014). Unfortunately, data concerning the biological aspects of sperm and their fertility in…”

Inhibitory effect of K+ and Ca2+ concentrations, pH, and osmolality of activation solution on motility of shabut (Barbus grypus Heckel 1843) spermatozoa

“…Motility of salmonid sperm is sensitive to very low concentrations of K + (more than 1 mM) (28), which are lower than levels for sturgeon sperm (more than 2 mM) (29). K + can control activation in sturgeon sperm at very low concentrations (0.01-0.3 mM) in A. baeri, A. persicus, P. spathula, and A. fulvescens sperm (12,13).…”