褶皱臂尾轮虫不同时期休眠卵的超微结构

分别用光学显微镜、扫描电子显微镜和透射电子显微镜对褶皱臂尾轮虫(Brachionusplicatilis)新产的和隔年的休眠卵形态结构进行观察。结果表明,两个时期的休眠卵外壳结构有区别,隔年卵外壳较薄,壳纹不明显;新卵外壳厚,壳纹明显。进行轮虫休眠卵分类时应以后者为准。新产休眠卵无气室,而隔年休眠卵有气室。进一步观察表明,休眠卵气室中的气体由休眠期间的代谢活动而产生。扫描电镜下,新产休眠卵有2层卵膜,隔年休眠卵有3层卵膜;透射电镜下,二者均为3层卵膜,不同时期休眠卵的每层卵膜厚度及细微结构有所差别。这两个时期的休眠卵胚胎结构上均有2层,但内含物有所不同。

Ultrastructural studies on resting eggs of Brachionus plicatilis at different stages

The ultrastructures of newborn and several-year-old resting eggs of the rotifer Brachionus plicatilis were observed under light microscope, scanning electron microscope and transmission electron microscope. The shell structure of several-year-old egg is different from that of the newborn. On the other hand, the stripes in the outer shell surfaces of newborn resting eggs are distinct, but those of the several-year-old eggs are not. Observations showed that there is an air bubble in the several-year-old resting egg which was produced during the metabolism when it resting, but in the newborn egg there is not. Under scanning electron microscope, two shell layers are found in every newborn resting egg, whereas there are three shell layers in the several-year-old egg. Under transmission electron microscope, both have three shell layers, in which the ultrastructure and thickness are different. There are two layers in both kinds of embryos with different contents.