Previous work relating adult age data to historic hydrology indicated that strong year‐classes of Alligator Gar Atractosteus spatula were rare, tied to major flooding events, and linked to the inundation and connectivity of floodplain habitats. Although spawning habitat suitability criteria have been correlated with successful recruitment in Texas Alligator Gar populations, direct evaluation of recruitment documenting young‐of‐the‐year (age‐0) presence or abundance has not been reported. To specify conditions associated with successful spawning and recruitment of Alligator Gar, we sampled for age‐0 fish monthly from May to July 2013–2017 in the Trinity River and from May to July 2015–2017 in Choke Canyon Reservoir. Suitability criteria predicted strong year‐classes in 2015 and 2016 for the Trinity River and in 2015 for Choke Canyon Reservoir; the predictions were confirmed by the presence of abundant age‐0 Alligator Gar in those systems and years. Hatch dates of juvenile Alligator Gar were estimated from otoliths and compared to corresponding environmental and hydrologic conditions. Hatch date analyses indicated a protracted spawning duration in 2015 associated with extended widespread flooding and a narrower range of spawning dates in 2016. Due to rapid growth and variable gear efficacy relative to fish size, multiple gears were required to assess the full size range of age‐0 Alligator Gar. A standardized sampling framework that included visual searching and floating mini‐fyke nets effectively sampled age‐0 Alligator Gar from 15 to 650 mm TL. We recommend a two‐tiered approach for predicting and monitoring Alligator Gar recruitment. First, the monitoring of hydrology and the application of suitability criteria can provide an early predictor of potential Alligator Gar reproductive success. If conditions are favorable for spawning, then sampling for age‐0 Alligator Gar can confirm recruitment and can give an indication of the spatial extent (visual searching) and relative abundance (visual searching and/or mini‐fyke nets) of successful reproduction.

中文翻译：

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鳄鱼Gar繁殖成功与水文相关

以前将成年年龄数据与历史水文学联系起来的工作表明，短吻鳄鳄铲的年级高罕见，与重大洪水事件有关，与洪泛区栖息地的淹没和连通性有关。尽管产卵栖息地的适宜性标准与德克萨斯州短吻鳄Gar种群的成功招募有关，但尚未报告对年幼（0岁）存在或丰度进行记录的招募的直接评估。为了说明与成功繁殖和募集扬子鳄相关的条件，我们在三一河中从2013年5月至2013年7月至2017年7月至2015年7月至2017年7月在Ch谷峡谷水库采样了0岁年龄的鱼类。适宜性标准预测三位一体河在2015年和2016年以及Ch谷峡谷水库在2015年将有很强的年份。这些系统和年份中存在大量的0岁鳄鱼皮Gar证实了这些预测。从耳石中估计幼年扬子鳄的孵化日期，并将其与相应的环境和水文条件进行比较。孵化日期分析表明，2015年产卵持续时间长，洪水泛滥时间延长，2016年产卵日期范围缩小。由于鱼类生长迅速且渔具功效与鱼类大小有关，因此需要多个渔具来评估整个年龄范围‐0鳄鱼皮 包括视觉搜索和浮动微型鱼网的标准化采样框架可有效采样15至650 mm TL的0岁鳄鱼皮。我们建议采用两层方法来预测和监视扬子鳄的招聘。首先，水文监测和适用性标准的应用可以为潜在的扬子鳄Gar繁殖成功提供早期预测。