Anadromous Rainbow Smelt Osmerus mordax provide an important nearshore prey base, but they have experienced severe population declines during the last century. Population estimates from spawning run surveys have not been calculated because within‐season repeat spawning, a behavior qualitatively described for this species based on previous studies, has not been quantified. Our objective was to determine repeat spawning behavior at two spawning sites by using passive integrated transponder technology. A preliminary laboratory tag retention and mortality study was performed to determine the effect of tagging on study results, and it showed that tagging did not cause significant mortality and tags were well retained. In our field studies, continuous monitoring of tagged fish showed that Rainbow Smelt made movements to the spawning grounds against the tide and at low tide, allowing the fish to be at the spawning grounds during the darkest nighttime hours. This is in contrast to past assumptions that Rainbow Smelt only spawn during nighttime high tide. We found that repeat spawning behavior was a predominantly male behavior, consistent with past studies. The behavior of males did vary between the two sites, although at each site the behavior was consistent among study years. In contrast, the behavior of females was consistent both among study years and between the sites. This finding indicates that future assessments of spawning populations of Rainbow Smelt could be improved by using female catch numbers, similar to other species that display skewed sex ratios.

中文翻译：

---

量化Rainbow Smelt的季节内重复产卵，对比较性别比率和运行之间的调查捕捉具有影响

残酷的彩虹熔炼臭臭的奥斯曼鲁斯提供了重要的近岸猎物基地，但在上个世纪，它们经历了严重的人口下降。未计算产卵运行调查的种群估计数，因为尚未对季节内重复产卵（根据先前的研究对该物种定性描述的行为）进行量化。我们的目标是通过使用被动集成应答器技术来确定两个产卵位置的重复产卵行为。进行了初步的实验室标签保留和死亡率研究，以确定标签对研究结果的影响，结果表明，标签未引起明显的死亡率，并且标签保留良好。在我们的田间研究中，对带标签鱼的持续监测表明，彩虹熔炼在潮汐和退潮时向产卵场移动，允许鱼在最黑的夜间处于产卵场。这与过去的假设“彩虹熔炼仅在夜间涨潮时产卵”形成对比。我们发现重复产卵行为主要是男性行为，与以往的研究一致。男性的行为确实在两个地点之间有所不同，尽管在每个地点的行为在研究年间是一致的。相反，女性的行为在研究年份之间和地点之间都是一致的。这一发现表明，通过使用雌性捕捞数量，类似于其他显示出性别比例偏斜的物种，可以改善对彩虹熔炼产卵种群的未来评估。这与过去的假设“彩虹熔炼仅在夜间涨潮时产卵”形成对比。我们发现重复产卵行为主要是男性行为，与以往的研究一致。男性的行为确实在两个地点之间有所不同，尽管在每个地点的行为在研究年间是一致的。相反，女性的行为在研究年份之间和地点之间都是一致的。这一发现表明，通过使用雌性捕捞数量，类似于其他显示出性别比例偏斜的物种，可以改善对彩虹熔炼产卵种群的未来评估。这与过去的假设“彩虹熔炼仅在夜间涨潮时产卵”形成对比。我们发现重复产卵行为主要是男性行为，与以往的研究一致。男性的行为确实在两个地点之间有所不同，尽管在每个地点的行为在研究年间是一致的。相反，女性的行为在研究年份之间和地点之间都是一致的。这一发现表明，通过使用雌性捕捞数量，类似于其他显示出性别比例偏斜的物种，可以改善对彩虹熔炼产卵种群的未来评估。相反，女性的行为在研究年份之间和地点之间都是一致的。这一发现表明，通过使用雌性捕捞数量，类似于其他显示出性别比例偏斜的物种，可以改善对彩虹熔炼产卵种群的未来评估。相反，女性的行为在研究年份之间和地点之间都是一致的。这一发现表明，通过使用雌性捕捞数量，类似于其他显示出性别比例偏斜的物种，可以改善对彩虹熔炼产卵种群的未来评估。