Evaluating the upper thermal limits of glochidia for selected freshwater mussel species (Bivalvia: Unionidae) in central and east Texas, and the implications for their conservation
Evaluating the upper thermal limits of glochidia for selected freshwater mussel species (Bivalvia: Unionidae) in central and east Texas, and the implications for their conservation
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DOI：
10.1002/aqc.3136
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发表时间：
2019-07-17
影响因子：
2.4
通讯作者：
Randklev, Charles R.
中科院分区：
文献类型：
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作者：
Khan, Jennifer M.;Hart, Michael;Randklev, Charles R.
了解生物体的温度耐受性至关重要，因为淡水生态系统的温度状况正在全球范围内发生变化。由于其生理和独特的生活史，本地淡水贻贝对水温升高很敏感。贻贝致死温度的详细知识已被限制在已知发生在北美的物种的不到5%，并鲜为人知的是从美国西南部的河流贻贝物种的耐热性。为了确定升高的水温对贻贝的影响，在德克萨斯州的四个盆地（内奇斯，瓜达拉哈拉，圣安东尼奥和科罗拉多）对以下物种的幼虫（钩介）的上限耐热性进行了测试：Amblema plicata，Cyclonaias necki，Fusconaia mitchelli，Lampsilis bracteata，Lampsilis hydiana，Lampsilis satura，Lampsilis teres和Obovaria arkansasensis。在24小时标准急性实验室测试中，在实验温度范围（30-39摄氏度）内使钩介体适应27摄氏度。钩介虫的半数致死温度（LT_（50））平均为32.4 ℃，范围为26.9 ~ 36.4 ℃。耐热性显着不同物种之间和内部，并按季节。将这些结果与德克萨斯州中部和东部目前的水温进行比较表明，所研究的重点物种种群面临环境温度上升的风险，因此，它们的长期生存能力在未来几年将面临挑战。
Understanding the temperature tolerances of organisms is critical because the thermal regimes of freshwater ecosystems are changing globally. Native freshwater mussels are sensitive to increasing water temperatures because of their physiology and unique life history. Detailed knowledge on lethal temperatures for mussels has been limited to less than 5% of the species known to occur in North America, and little is known about the thermal tolerances of mussel species from rivers within the south-western USA. To determine the effects of elevated water temperature on mussels, the upper thermal tolerances of larvae (glochidia) for the following species across four basins in Texas (Neches, Guadalupe, San Antonio, and Colorado) were tested: Amblema plicata, Cyclonaias necki, Fusconaia mitchelli, Lampsilis bracteata, Lampsilis hydiana, Lampsilis satura, Lampsilis teres, and Obovaria arkansasensis. Glochidia were acclimated to 27 degrees C across a range of experimental temperatures (30-39 degrees C) in 24-h standard acute laboratory tests. The median lethal temperature (LT50) among glochidia averaged 32.4 degrees C and ranged from 26.9 to 36.4 degrees C. Thermal tolerances differed significantly among and within species, and by season. Comparing these results with current water temperatures in central and east Texas indicated that populations of the focal species studied are at risk from rising environmental temperatures and, as a consequence, their long-term viability will be challenging in future years.