家养鱼类受精生物学的研究 Ⅱ.几种淡水鱼类成熟卵球的精孔器与精子入卵通路的光镜与扫描电镜观察

作者对我国四种淡水养殖鱼类——团头鲂、草鱼、白鲢和花鲢卵球的精孔器作了光学显微镜和扫描电子显微镜的比较描述,在扫描电子显微镜下观察到这几种鱼类的精子均直接经精孔器前庭穿过精孔管进入卵内,并对精孔细胞、受精孔与精子入卵的关系以及精孔的位置进行了讨论。  

SCANNING ELECTRON MICROSCOPIC AND LIGHT MICROSCOPIC OBSERVATIONS ON THE MICROPYLE APPARATUS AND THE PATHWAY OF SPERM PENETRATION INTO THE MATURED EGG IN FOUR FRESHWATER FISHES (WUCHANG FISH,GRASS CARP,SILVER CARP AND BIG HEAD)

Surrounding membranes (chorion) of the matured eggs in these four Chinese pond fishes (Megalobrama amblycephala Ctenopharyngodon idellus, Hypophthalmichthys molitrix and Aristickthys nobilis) are all tough. The sperm penetration into the matured egg is restricted to the micropylar canal of the chorion, but there is no micropylar cell above the canal.There is a funnel-like depression in front of the micropylar canal; an outer opening of the canal is situated on the bottom of the depression, so that this depression is the vestibule of the micropyle apparatus. While the micropyle itself is a canal-like structure surrounded by the chorion and opens to the surface of plasma membrane on the animal pole directly, therefore, it is called the micropylar canal. The diameters of the outer and inner openings of the micropylar canal are different from each species, the outer opening being 4 to 4.5μ M in Wuchang fish and about 3 to 3.5μ M in grass carp and silver carp. while the inner opening of the canal being always smaller than the outer one.In short, the micropyle apparatus of matured eggs in these studied fishes are all formed of one funnel-like vestibule and an outer circular opening of the micropylar canal at its bottom, while the pathway of sperm penetration into the matured egg is only the micropylar canal.