| 摘要: |
| 于1988－1991年在青岛对中国对虾进行受精能力和受精生物学的研究。对虾采用加温和不加温培育，然后用人工授精法-水域法和滴管法授精研究精卵受精能力；应用扫描和透射电镜以及石蜡切片技术，观察精卵的形态结构和受精过程的变化。结果表明，水域法授精，精子入水后3h仍具有受精能力；卵子入水后1 min之内受精率最高只达62.7％。而滴管法授精，受精率最高可达到98％，平均值也在60％－80％之间。保持在低温的亲虾，其纳精囊中的精子，受精率都比较低，表明早期精子尚未完全成熟，卵子生理上的成熟是一瞬间之事。精卵接触后3－4min就完成了受精任务，卵子皮层反应与否与受精无必然联系。观察表明，精子呈“洗耳球”状，由核体部和顶体两部分组成。卵子皮质层排列着众多的皮质棒，遇水便立即释放于水中，形成一层透明胶质层。观察并描述了受精后精卵的外部和内部的形态变化，雌雄原核的结合以及第一次卵裂过程。 |
| 关键词: 中国对虾 人工授精 受精生物学 |
| DOI： |
| 分类号: |
| 基金项目:国家“七五”科技重点攻关项目，D17860308号 |
附件 |
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| BIOLOGY OF FERTILIZATION IN PENAEUS CHINENSIS |
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Cai Nan'er, Lin Feng, Chen Bennan, Ke Yafu, Tong Baofu
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Institute of Oceanology , Chinese Academy of Sciences, Qingdao 266071
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| Abstract: |
| Studies on the fertilization biology of Penaeus chinensis were carried out using the method of fertilizing in seawater and in dropper from 1988 -1991. The overwinter and wild broodstocks collected from Rizhao were divided into two groups: (1) A heating group with water temperatures of up to 14 - 15°C. (2) A non-heating group (12 °C). The outside morphology and the inside structure of the sperm were observed using SEM and TEM; those of the egg were studied using the common microscopic section technique.
The results show that the ability of fertilization can preserve 3h after sperm releasing in seawater. The fertilization rate was 62.7% for the method of fertilized in seawater within 1 min after egg releasing. Maximum rates of fertilization reach more than 98%, with an average from 60% to 80% using the dropper method. On the other hand, the fertilization rate is reduced in low temperature because the sperms are not completely mature.
Sperms of P. chinensis, with a shape like a suction ear ball, are composed of two main parts: a spherical nuclear body and an acrosome. The acrosome consists of spike, an acrosomal cone, an acrosomal cap and a cap core region containing the cap core granule. The change in a fertilized sperm can be divided into 4 stages. (1) The tip of the spike expends and the vesicle is formed. (2) The vesicle expends and turns around or shrinks before dropping. (3) The acrosomal ?lament is released. (4) The front of sperm enters the egg and then the nuclear body of the sperm goes into with the vesicle.
When spawning into seawater, the egg releases the cortical rods; this cortex reaction can take place even without sperm-egg interaction. The course of the gamete interaction in the temperature of 18.5°C is: 1 min after fertilization, the egg releases cortical rods around it; after 4 - 5min, the sperm enters the egg and finishes the fertilization task; 10 min, the egg carries out the first maturation division and releases the first polar body; 25 min, the egg membrane (also called the fertilization membrane) rises up; 30 min, the second maturation division is finished, releasing the second polar body; 55-60 min, the two pronucleus combine and form a zygote nucleus; 85 min, the first cleavage is finished and forms two cleavage cells.
The maturity of the egg is physiologically reached in a very short time. During this period, some hormone is rapidly secreted in the body. With the presence of this hormone, the egg is stimulated to reach physiological maturity. The cortical reaction of eggs is not necessarily related to the fertilization. |
| Key words: Penaeus chinensis, Artificial fertilization, Fertilization biology |
