【摘要】 利用2015年4-7月共6个航次在长江口近岸水域的调查数据,对该水域小黄鱼仔稚鱼的时空分布和生长变化特征进行了研究。结果表明:小黄鱼仔稚鱼的平均出现率为51.85%,以6月中旬最高,4月中旬次之,7月中旬最低,S断面的平均出现率明显大于N断面;站位总平均丰度为3.27尾·100-1·m^-3,以5月中旬最高,5月上旬次之,7月中旬最低,S断面小于N断面。S断面的出现率较高,N断面的高丰度站位随时间的推移向外海转移。总体来看,30 m以浅水域的丰度先升高后降低,5月中旬达到峰值;30 m以深水域的丰度随时间推移逐渐下降;丰度随水深增加而减小。根据仔稚鱼不同发育期在各时间段所占的百分比,把其生长发育过程分为仔鱼期、仔稚鱼期和稚幼鱼期等3个阶段,相对应的时间段分别为4月中旬至5月上旬、5月中旬至6月上旬和6月中旬至7月中旬。春末夏初,河口水域快速上升的水温以及由冲淡水增强形成的低盐环境有利于提高仔稚鱼的存活率,增强其对环境的适应能力。更多还原

【Abstract】 Based on the data of 6 cruises collected during April – July 2015 in the coastal waters of the Yangtze River Estuary,the temporal and spatial distribution and growth characteristics of small yellow croaker（ Larimichthys polyactis） larvae and juveniles were studied. The results showed that the average occurrence rate of larvae and juveniles was 51. 85%,the highest was in Mid-June,the second in mid-April,the lowest in mid-July,and the average occurrence rate of S section was significantly greater than that of N. The total average abundance of stations was 3. 27 ind ·100-1·m^-3,which was the highest in mid-May,second in early May,lowest in mid-July,and S section was smaller than N. The occurrence rate of S section was higher,and the height of N section was transferred to the outer sea over time. In general,the abundance of less than 30 m waters increased first and then decreased,reaching peak in mid-May. The abundance of more than 30 m waters gradually declined over time. The abundance decreased with the depth of the water.According to the percentage taken of larvae and juveniles in each time period at different developmental stages,its growth process was divided into the larval stage,larvae and juveniles stage,juveniles and young fish stage,and the corresponding period was respectively in the mid-April to early May,in mid-May to early June and the mid-June to mid-July. At the beginning of late spring and early summer,the rapidly rising water temperature of estuarine waters and the low salinity environment formed by the strengthening of dilute water can improve the survival rate of young fish and enhance its adaptability to the environment,coastal waters of the Yangtze River Estuary in this period were good nursery grounds and feeding grounds for the small yellow croaker larvae and juveniles. In late spring and early summer,the abundance of the larvae and juveniles showed the tendency of decreasing with the increasing water depth,but in mid-July,they only appeared in shallow 20 m water areas with low abundance. From mid-April to mid-May when water temperature increased and salinity decreased in the Yangtze River Estuary,the environmental conditions for the spawning of the small yellow croaker were mature; and from mid-May to mid-July,the high-temperature and low-salinity features of the area is beneficial for the growth of early-stage larvae and juveniles,also for the growth of their bait,plankton.更多还原