ABSTRACT As global temperatures rise, streams and rivers are predicted to be more severely impacted than other ecosystems, due in part to the limited mobility of aquatic invertebrates. Compared to many terrestrial animals, freshwater snails have particularly low potential for migration and thus are not expected to be able to compensate for climate warming with active dispersal. In freshwater animals, several behaviors are affected by elevated temperatures, including burrowing and escape responses, among others. This laboratory study aimed to assess the impacts of elevated temperatures on righting behavior and survival in two species of freshwater caenogastropod snails: fine-ridged elimia (Elimia semicarinata) and Shawnee rocksnails (Lithasia obovata). Righting time (the time to turn the body right-side-up when placed on the dorsal side of the shell) was assessed before beginning the experiment and again after chronic (10 day) exposure to an elevated temperature. There was no significant change in righting time at any temperature for either species, but there was significantly more failure to right within the time limit at elevated temperatures. For fine-ridged elimia, 30% of the snails failed to right in 30°C, compared to 2.5% in the control temperature (20°C). Similarly, 47.8% of Shawnee rocksnails failed to right at 27°C, while 19.4% failed to right in the 20°C group. Mortality was significantly higher at 35°C for fine-ridged elimia and 30°C for Shawnee rocksnails compared to the mortality of each species’ control group. Predicted rates of climate warming and current average temperatures suggest that fine-ridged elimia face more imminent risk of large-scale failure to right within natural populations, but the lower lethal temperature for Shawnee rocksnails suggests relatively high risk as well. These results contribute to the growing body of evidence that freshwater snails will be negatively impacted by climate warming, and may face large losses in the years to come.

中文翻译：

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水温升高对两种淡水盲腹足蜗牛的扶正行为和存活的影响

摘要随着全球气温升高，预计溪流和河流将比其他生态系统受到更严重的影响，部分原因是水生无脊椎动物的流动性有限。与许多陆生动物相比，淡水蜗牛的迁徙潜力特别低，因此预计无法通过主动扩散来补偿气候变暖。在淡水动物中，温度升高会影响几种行为，包括挖洞和逃跑反应等。本实验室研究旨在评估高温对两种淡水 Caenogastropod 蜗牛：细脊蜗牛 (Elimia semicarinata) 和肖尼岩钉 (Lithasia obovata) 的扶正行为和生存的影响。在开始实验之前和在长期（10 天）暴露于高温后再次评估翻正时间（当放置在壳的背面时将身体正面朝上的时间）。任一物种在任何温度下的扶正时间都没有显着变化，但在升高的温度下，在时限内扶正失败的情况明显更多。对于细脊蜗牛，在 30°C 下有 30% 的蜗牛无法正确，而在控制温度 (20°C) 下则为 2.5%。同样，47.8% 的肖尼岩钉未能在 27°C 下正确，而 19.4% 在 20°C 组中未能正确。与每个物种的对照组的死亡率相比，35°C 下细脊 elimia 和肖尼岩钉的死亡率显着高于 30°C。气候变暖的预测速度和当前的平均温度表明，细脊线虫在自然种群中面临更大的大规模失败风险，但肖尼岩钉的致死温度较低也表明风险相对较高。这些结果有助于越来越多的证据表明淡水蜗牛将受到气候变暖的负面影响，并可能在未来几年面临巨大损失。