鱼类早期生活史在旧金山河口和分水岭
生态学的幼虫在旧金山河口太平洋鲱鱼:bob娱官网入口季节和年际丰富,分布,饮食,和条件
斯蒂芬·m·发斯和艾莉森·m·桑德斯
doi:https://doi.org/10.47886/9781888569599.ch2
抽象的。太bob娱官网入口平洋鲱鱼Clupea pallasi是一个商业和生态重要鱼类产生的相当大的股票,在其早期生活史在旧金山河口(技术)。然而很少有人了解的基本生态幼虫太平洋鲱鱼在超临界流体。bob娱官网入口我们进行了3年的野外研究(1999 - 2002),主要集中在冬季和春季收集超临界流体在两个地区(中央和San Pablo海湾),解决三个目标:(1)确定季节性丰富模式两湾幼虫太平洋鲱鱼,(2)检查幼虫的饮食太平洋鲱鱼,和(3)评估两湾幼虫太平洋鲱鱼的条件。bob娱官网入口bob娱官网入口太平洋鲱鱼是一个引人注目的组件的冬季幼虫鱼组合在圣巴勃罗和中央海湾,由最高总丰度的22.5%和5.5%,分别。幼虫太平洋鲱鱼bob娱官网入口数量每年在2月或3月达到顶峰,最大密度达到2.53 /米3(San Pablo)和0.52 /米3(中央湾)。长度频率分布表明,每年至少2 - 3军团被产生,一些证据表明,幼虫在圣巴勃罗湾略大。幼虫太平洋鲱鱼bob娱官网入口美联储广泛的猎物类型,包括tintinnids copepodids,桡足类无节幼虫,硅藻和腹足类动物面盘幼体。很高比例的tintinnids饮食(87%,2001年3月)表明一个重要protozoan-metazoan联系。幼虫的条件评估的协方差分析(即“增长敏感的”变量。,body weight, anal body depth, or pectoral body depth) regressed against a “growth insensitive” variable (i.e., standard length). These results showed marked differences between the bays: in Central Bay, early (small) larvae exhibited better condition, but within San Pablo Bay, larvae exhibited a greater rate of improved condition with increasing age (size). This suggests the possibility of important differences in the Central and San Pablo bays as larval Pacific herring nursery grounds. Several areas of future research on the ecology of larval Pacific herring in SFE are recommended (e.g., coupling between horizontal and vertical distributions and advective flow fields, predation, and feeding dynamics on protozoan versus metazoan prey).