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根据2005年4和11月、2006年4和9月在长江河口水域进行的鱼卵、仔稚鱼种类和数量调查,并结合1990年9月和1991年3月的历史数据,对该水域的鱼卵、仔稚鱼群落结构的种类组成和数量的季节变化作了研究,其结果共发现鱼卵、仔稚鱼36种(类),以海洋鱼类种类最多。秋季航次鱼卵、仔稚鱼的平均种类数和丰度均高于春季。河口咸淡水区鱼卵总数显著高于淡水区,而仔稚鱼总数略低于淡水区。与1990—1991年数据相比,2005—2006年春、秋季的鱼卵和仔稚鱼丰度均有所增加。1990、2006年秋季(9月)鱼卵、仔稚鱼种类组成差异较大,特别是翘嘴红鲌和太湖新银鱼丰度差异较大。这些都说明近20年来,长江河口水域鱼卵、仔稚鱼种类组成和数量均发生了明显的改变。
Based on the survey of the species and abundance of eggs, larvae and juveniles in the waters of the Yangtze River estuary in April and November 2005 in April and September of 2005 and the historical data of September 1990 and March 1991, The results showed that there were 36 species of fish eggs and larvae, with the largest number of marine fish species. The average number and abundance of autumn eggs and larvae were higher than those in spring. The total number of eggs in the brackish freshwater estuaries was significantly higher than that in freshwater areas, while the total number of juveniles was slightly lower than that in freshwater areas. Compared with the data of 1990-1991, the abundance of fish eggs and juveniles increased in spring and autumn 2005-2006. The species composition of fish eggs and larvae varied greatly in the fall (September) of 1990 and 2006 (2006). All this shows that in the recent 20 years, the composition and number of fish eggs, larvae and juveniles in the Yangtze River Estuary have undergone obvious changes.