Light trap captures of larval Razorback Sucker Xyrauchen texanus are used to trigger flow releases from Flaming Gorge Reservoir, which inundate floodplain wetland nursery habitat in the Green River, Utah. However, because little is known about the efficacy of traps to capture or retain larvae under field‐relevant conditions, we conducted an exploratory study using releases of unmarked and marked (oxytetracycline hydrochloride) early life stages of Razorback Sucker (mesolarval life stage, hereafter called “larvae”) in the 53‐ha Leota‐10 wetland of the middle Green River. Batches of 10, 50, 250, or 1,000 larvae were released 3‐ or 10‐m from light traps. Light traps had either chemical light stick or LED light sources, and releases were made on two successive evenings to assess recapture proportions. Light traps recaptured larvae each night and at all release abundances in this large and open habitat. Recapture proportions (number recaptured per number released) for individual traps ranged from 0 to 0.68 (mean = 0.11) over the two release nights. Because recapture proportions were similar over all release abundances, light trap captures may be an index of larvae abundance. In addition, recapture proportions of larvae in traps (light sources combined) were not influenced by release distance. Nonsignificant tests for release distance and release abundance effects had low statistical power resulting from high sample variability and modest sample sizes, so additional experiments are required to confirm those results. The ANCOVA also indicated that traps with an LED light source had consistently higher recapture proportions than traps lit with chemical light sticks, in support of laboratory findings. Although additional experiments with greater replication are needed to better understand attraction distance, release abundance, and retention effects, light traps may be a useful tool to monitor presence and abundance of larvae. This information will aid management and conservation of endangered Razorback Sucker in the Colorado River basin.

中文翻译：

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在大型洪泛区湿地捕获捕鼠人吸盘幼虫的光陷阱效能

幼虫Razorback Sucker Xyrauchen texanus的光陷阱捕获 用来触发火焰状峡谷水库的水流释放，这淹没了犹他州格林河的洪泛区湿地苗圃栖息地。但是，由于对捕虫器在野外相关条件下捕获或保留幼虫的功效知之甚少，因此我们进行了一项探索性研究，使用了Razorback Sucker的未标记和标记的（盐酸土霉素）早期生命期（中膜生命期，以下称为“幼虫”）位于格林河中游53公顷的Leota-10湿地中。从诱捕器3或10 m处放出10、50、250或1,000个幼虫批次。陷阱使用化学荧光棒或LED光源，并在两个连续的晚上释放以评估捕获比例。每天晚上，诱捕器都会捕获幼虫，并在这个广阔而开放的栖息地释放大量的幼虫。在两个发布之夜中，单个陷阱的捕获比例（每个释放的捕获数量）为0到0.68（平均= 0.11）。由于所有释放丰度的捕获比例均相似，因此捕获光阱可能是幼虫丰度的指标。此外，捕虫器（结合光源）中幼虫的重新捕获比例不受释放距离的影响。对于释放距离和释放丰度的影响不显着的测试由于高的样本可变性和适度的样本量而导致统计能力低，因此需要额外的实验来确认这些结果。ANCOVA还指出，使用LED光源的诱捕器比使用化学荧光棒点亮的诱捕器具有更高的捕获比例，以支持实验室的发现。尽管需要进行更多重复实验以更好地了解吸引距离，释放丰度和保留效果，但是光阱可能是监测幼虫存在和丰度的有用工具。这些信息将有助于科罗拉多河流域濒危的Razorback Sucker的管理和保护。