斜带石斑鱼精子超微结构及盐度、温度、pH对精子活力及寿命的影响

Ultrastructure of spermatozoa and effects of salinity, temperature and pH on spermatozoa motility in Epiniphelus coioides

选取健康雄性斜带石斑鱼(Epinepheluscoioides)亲鱼进行人工采精,以日立H-600型透射电镜观察精子超微结构,同时设定盐度梯度、温度梯度和pH梯度,观察其对精子活力的影响。超微观察显示,精子头部呈圆形或卵圆形,核膜与质膜间的空间较大;近端中心粒的长轴与尾部约成120°的夹角;基体位于鞭毛顶端,长轴与精子头部细胞核长轴平行;袖套位于核后端,呈筒状,两侧不对称,分布着数量、大小不等的线粒体和囊泡。尾部细长,长26.0～31.5μm,其主要结构是轴丝,轴丝为典型的"9+2"微管结构。活力实验显示,精子活力的最适盐度为27～35,盐度33时精子寿命最长,为27min;最适pH为6.5～8.7,pH8.4时精子运动时间最长,为20min;最适温度为25～31℃,29℃时精子寿命最长,为37min。

The healthy male Epiniphelus coioides Zwere employed(body weight 8.2-13.2 kg, body length 64-78 cm), and the spermatozoa were collected from the fish body by artificial conduction. Under the transmission electron microscope, the observation shows that the spermatozoon consists of two parts: the head and the tail. A large nucleus shaped round or ellipse with condensed chromatin is located in the head. The space between the membrane of the nucleus and cytoplasm is relatively large. The proximal centriole has a 120 degree angle with the major axis of the spermatozoon, whereas the basal body is parallel to the major axis of the nucleus. The two wings of the column-like sleeve is asymmetry. The central structure of the tail is axoneme with a typical structure of the 9+2 model. When the salinity of sea water at 27-35, the spermatozoa have the best motility and the spermatozoa have the longest life span at salinity 33, which is 27 min. When pH at 6.5-8.7, the spermatozoa have the best motility, and at pH 8.4, the spermatozoa have the longest life span, which is 20 min. The effects of water temperature on spermatozoa motility showed that the optimum sea water temperature is 29 ℃when the spermatozoa have the longest life of span (20 min), and the optimum range of water temperature is 25-31 ℃.