Abstract: In order to study the physiological characteristics of sperm in Opsariichthy bidens, the effects of several environmental factors (pH value, glucose and ions solutions) on sperm motility were analyzed by determinating activation rate, moving time and life-span of sperm. The results indicated that the mean density of sperm was (1.227±0.13)×1010/mL. The results also showed higher values for sperm motility at pH 6.0~7.5, and the optimum result was obtained when the sperm was activated in the solution of pH 6.0. The activation rate, moving time and life-span were (77.67±3.51)%, (43.00±2.08)s and (47.67±1.00)s, respectively. The activation rate was lower when the sperm was activated in glucose solution during the concentration of 6-10 g/L. When the sperm was activated in the solution containing 9 g/L glucose, the activation rate, moving time and life-span of sperm were (41.66±7.02)%, (9.33±8.62)s and (51.00±19.70)s, respectively, and only this group observed the normal movement of the sperm. What′s more, it was found that K+ and Na+ could improve the sperm motility of O. bidens. The activation rate, moving time and life-span of sperm could reach to (80.00±5.29)%, (108.67±18.04)s and (697.00±47.03)s, respectively, in KCl solution (5 g/L). The activation rate, moving time and life-span were (60.33±7.77)%, (33.00±13.11)s and (208.00±54.84)s, respectively, when the sperm activated in NaCl solution(4 g/L). In the MgCl2 solution(1-5 g/L), a certain proportion of sperm could be activated, but the sperm just trembled in situ. The sperm of O. bidens could be activated in CaCl2 solution(1-5 g/L) too, and the optimum result obtained in the solution containing 1 g/L CaCl2: the activition rate, moving time and life-span of sperm were (50.33±1.53)%, (31.00±1.00)s and (34.67±2.52)s, respectively. A higher proportion of sperm was activated in the Cd2+ solution(0.000 5-5 mg/L), but the sperm died immediately after acute movement, and the adjustment of Cd2+ to 50 mg /L and 500 mg /L resulted in agglutination and death of sperm.

Key words: Opsariichthys bidens, sperm, motility, environmental factors