摘要
以1981～2004年间捕获的中华鲟(AcipensersinensisGray)亲鲟样本为研究材料,研究葛洲坝截流24年来中华鲟繁殖季节中坝下30km范围内产卵群体结构的变化情况。测定与统计结果显示,中华鲟雌雄性比由1981～1983年的1.10∶1降低到1987～1989年的0.63∶1,而后上升到2003～2004年的5.86∶1。雌鲟平均体长由1990～1992年的263.1cm增加到1999～2001年的276.7cm,升幅为5.2%(差异极显著);平均体重由1990～1992年的202.4kg增加到2003～2004年的237.4kg,升幅为17.3%(差异显著)。雌鲟年龄的平均值在24年中的前9年里(1981～1989年)波动于19.0～20.7龄,在后15年(1990～2004年)里,雌鲟年龄平均值在21.1～22.7龄之间波动,普遍高于前9年中的年龄平均值。雄鲟群体变化比雌鲟群体变化大。雄鲟平均体长、体重分别由1981～1983年的205.1cm、89.8kg下降到1987～1989年的197.5cm、72.7kg(降幅分别为3.7%、19.0%),然后上升到2003～2004年的229.4cm、121.1kg(升幅分别为16.4%、65.2%);平均年龄由1981～1983年的15.4龄下降到1987～1989年的13.3龄(降幅为13.6%),然后上升到1996～1998年的17.6龄(升幅32.3%)。在1993～2004年中华鲟产卵场采集并鉴定了年龄的中华鲟亲鲟中,共发现28尾1981～1989年出生的个体即葛洲坝截流后出生的个体,这证明了在洄游路径缩短622～1166km后,中华鲟的回归本能尚未丧失,同时,由于在葛洲坝截流后的初期并没有实施人工繁殖放流,这佐证了葛洲坝截流后新形成的中华鲟产卵场的有效性。
The Chinese sturgeon, Acipenser sinensis, is an anadromous fish. The migration pattern is only given for the population entering the Yangtze River. The spawning migration route was blocked by construction of the Gezhouba Dam in 1981 and the spawning ground, which has been found since then, is now located in the reach about 7?km below the dam. The variations in the spawning stock structure in the reach about 30?km below the dam from 1981 to 2004 during the spawning season were investigated. The sex ratio (F∶M) gradually decreased from 1.10∶1 during 1981-1983 to 0.63∶1 during 1987-1989, and then increased to 5.86∶1 during 2003-2004. The average body length of the females increased from 263.1?cm during 1990-1991 to 276.7?cm during 1999-2001, increasing by 5.2%; the average body weight increased from 202.4?kg during 1990-1992 to 237.4?kg during 2003-2004, increasing by 14.5%; the average age fluctuating between 21.1 and 22.7 years during 1990-2001 was older than that during 1981-1989, which was fluctuating between 19.0 and 20.7 years. The changes were greater in males than those in females. The average body length and body weight of the males decreased from 205.1?cm and 89.8?kg during 1981-1983 to 197.5?cm and 72.7?kg during 1987-1989, decreasing by 3.7% and 19.0%, respectively, and then increased to 229.4?cm and 120.1?kg during 2003-2004,increasing by 16.2% and 65.2%. The average age of males decreased from 15.4 years during 1981-1983 to 13.3 years during 1987-1989,decreasing by 13.6%, and then increased to 17.6 years during 1996-1998, increasing by 32.3%. In the individuals collected and age-determined during 1993-2004, there were 28 samples were born during 1981-1989. The results showed that the sturgeon did not lose their homing instinct as the migratory route was shorted off 622?km to 1?166?km since the damming in 1981. This verified that the new spawning ground below Gezhouba Dam was efficient since there was no restocking into the river in some years during 1980s.
出处
《中国水产科学》
CAS
CSCD
北大核心
2005年第4期452-457,共6页
Journal of Fishery Sciences of China
基金
国家自然科学基金项目(39570564)
重大项目(30490231)
国家社会公益研究专项(2000DIB50177)
基础工作重点专项.
关键词
中华鲟
产卵群体结构
长江
葛洲坝
Chinese sturgeon
spawning stock structure
the Yangtze River
Gezhouba Dam
