长江口纹缟虾虎鱼精子、卵子及受精过程扫描电镜观察

采用电镜对长江口纹缟虾虎鱼成熟精子、卵子及受精早期精子入卵过程进行了观察。结果显示:纹缟虾虎鱼成熟精子由头部和尾部两部分组成。头部呈圆形或近圆形,无顶体,细胞核长径为1.15±0.28μm,短径为0.97±0.22μm,尾部鞭毛长为8.17±1.12μm。核膜外具有双层质膜,质膜表面不平整,在核膜和双层质膜中间有较大空隙存在。中心粒复合体位于植入窝内。袖套两侧分布有2～3个较大的线粒体。鞭毛为典型的"9+2"结构,有侧鳍。成熟卵呈圆形,卵膜表面多沟和嵴,具单一受精孔,孔洞区外径约5μm,孔内壁呈螺旋嵴。在卵的植物极有一盘状突起,突起的中间为圆形,周边有呈网状结构的粘丝与卵壳膜连接。纹缟虾虎鱼精子入卵速度较快,受精过程较短,受精后10～18 s完成精子入卵过程。

Observation on spermatozoa, egg and sperm penetration of Tridentiger trigonocephalus by means of scanning electron microscopy

The mature eggs,spermatozoa and fertilization process of Tridentiger trigonocephalus taken from the Yangtze Estuary have been observed by means of scanning electron microscopy.It came to know that the sperm of T.trigonocephalus is belonged in the flagellum form.The spermatic head is almost round in shape and without acrosome.The long radius is 1.15±0.28 mm.The short radius is 0.97±0.22 mm.The length of flagellum is 8.17±1.12 mm.The surfaces of nucleus membrane and plasma membrane are not even.The space between the membrane of the nucleus and cytoplasm is relatively large.The implantation fossa is relatively shallow.The centriolar complex is consisted of proximal centriole and basal body.There are 2-3 mitochondria on the two sides of the central space of sleeve.The central structure of the tail is axoneme which formed a typical 9+2 pattern.The mature egg of T.trigonocephalus is sphaeroid,with only one micropyle.The outside of micropyle's diameter is about 5μm,and with spiral cristaes on the internal wall.There are lots of cristaes and ditchs on the surface of mature eggs.There is a dish-like tuber in the vegetal pole,the middle of which is rotundity.The circumjacent filaments connected tuber with the egg-membrane presented netlike configuration.The penetration of sperm into the eggs is quick and the process of the fertilization is short,the time of penetration needs 10 to 18s.