| 摘要: |
| 于1989年8月 - 1990年7月对青岛文昌鱼的生活史进行研究。结果表明：（1）青岛文昌鱼种群由4个年龄组组成，它至少生活4a以上，甚至可达6a左右。（2）在Ⅰ，Ⅱ龄时生长较快，平均年生长13－15mm，Ⅲ龄后生长速度减慢，即使同一年龄组的文昌鱼，在不同季节其生长速度也不同。（3）在冬春采集的文昌鱼中Ⅲ龄组的峰值较小。（4）繁殖季节过后，老龄文昌鱼因衰老而死亡。 |
| 关键词: 文昌鱼 生活史 年龄 生长 死亡 |
| DOI： |
| 分类号: |
| 基金项目:国家自然科学基金资助项目，3860811号 |
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| THE LIFE HISTORY OF BRANCHIOSTOMA BELCHERI TSINGTAUENSE: AGE, GROWTH AND DEATH |
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Wu Xianhan, Zhang Shicui, Wang Yongyuan, Zhang Baolu, Qu Yanmei, Jiang Xinji
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Institute of Oceanology, Acadcmia Sinica, Qingdao 266071
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| Abstract: |
| The life history of Branchioszoma belcheri tsingtauense was studied from Aug. 1989 to July 1990. The findings are as follows. (1) Its population consisted of four age groups of animals with lengths of 12 - 15, 24 - 27, 33 - 37 and 44 - 46mm, respectively. This suggests that B. belcheri tsingtauense might have a life span of at least four years. The amphioxus reaches a length of about 46 mm after four years of adult life and the largest animal collected at Qingdao was 58mm. It is presumed to have lived for six years or so. (2) The growth rate of B. belcheri tsirtgtauense decreased with age. The average rates of the one-, two-, three- and four-years old amphioxus were 1.25, 1.25, 1.08 and 0.75 mm/month, respectively. Also the growth rate for the amphioxus with the same age changed seasonally. They grew faster in Summer and Fall than in .Winter and Spring. This may result from the difference in seawater temperature, which ranges from 13.1°C to 26.5°C in Summer and Fall, and from 2. 2°C to 14.5°C in Winter and Spring at Qingdao. (3) High rate of mortality in B. belcheri tsingtauense may occur in the third or fourth year of life. In addition, death from senility among the older amphioxus population probably follows the spawning period as the number of the amphioxus with the maximum size decreased markedly after spawning. |
| Key words: Branchiostoma belclteri tsingtauente, Life history, Age, Growth, Death |
