Ichthyoplankton assemblage structure of springs in the Yangtze Estuary revealed by biological and environmental visions.
Ichthyoplankton assemblage structure of springs in the Yangtze Estuary revealed by biological and environmental visions.
复制标题
生物和环境视野揭示长江口泉水鱼类浮游生物组合结构
作者：
Zhang H;Xian W;Liu S
以1999年、2001年、2004年和2007年4个泉水为对象，对长江口浮游生物组合结构进行分析，以期详细刻画泉水浮游生物组合特征，考察泉水浮游生物组合的长期动态，评价环境因素对泉水浮游生物组合空间分布和年际变化的影响。与长江口相关的鱼类浮游生物组合。采集浮游鱼类23科42种。 Engraulidae 是数量最多的科，包括 6 个物种，占总渔获量的 67.91%。只有 4 个物种（Coilia mystus、Engraulis japonicus、Trachidermis fasciatus 和 Allanetta bleekeri）可以被认为是优势种，占总丰度的 88.70%。春季浮游鱼类组合的结构每年都会持续存在，尽管优势种的丰度每年有所波动，但它们的出现却始终如一。这种年际变化可能反映了受水母繁殖、河流流量减少和过度捕捞影响的可变环境条件。规范对应分析表明浮游鱼类组合的空间结构分为三个区域：（1）以C. mystus为主的内部组合； (2) 以 A. bleekeri 和 T. fasciatus 为主的中央组合； (3) 以日本刺猬为特色的架子组合。观察到的浮游鱼类组合结构似乎受到深度、盐度和悬浮颗粒物梯度的强烈影响。
The ichthyoplankton assemblage structure in the Yangtze Estuary was analyzed based on four springs in 1999, 2001, 2004 and 2007 in order to provide detailed characterizations of the ichthyoplankton assemblage in springs, examine the long-term dynamics of spring ichthyoplankton assemblages, and evaluate the influence of environmental factors on the spatial distribution and inter-annual variations of ichthyoplankton assemblages associated with the Yangtze Estuary. Forty-two ichthyoplankton species belonging to 23 families were collected. Engraulidae was the most abundant family, including six species and comprising 67.91% of the total catch. Only four species (Coilia mystus, Engraulis japonicus, Trachidermis fasciatus and Allanetta bleekeri) could be considered dominant, accounting for 88.70% of total abundance. The structure of the ichthyoplankton spring assemblage persisted on an annual basis, with the dominant species reappearing consistently even though their abundance fluctuated from year to year. This inter-annual variation probably reflects variable environmental conditions influenced by jellyfish blooms, declining river flow, and overfishing. Canonical correspondence analysis indicated aspatial structure of the ichthyoplankton assemblage in three areas: (1) an inner assemblage dominated by C. mystus; (2) a central assemblage dominated by A. bleekeri and T. fasciatus; and (3) a shelf assemblage featuring E. japonicus. The observed ichthyoplankton assemblage structure appears to be strongly influenced by depth, salinity and suspended particulate matter gradients.