Upper thermal tolerances of early life stages of freshwater mussels
Upper thermal tolerances of early life stages of freshwater mussels
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淡水贻贝生命早期阶段的耐热上限
DOI：
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发表时间：
2010
影响因子：
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通讯作者：
Edward J. Hammer
中科院分区：
文献类型：
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作者：
Tamara J. Pandolfo;W. Cope;C. Arellano;R. Bringolf;M. Barnhart;Edward J. Hammer
摘要蚌类在底栖水生生物群落中起着重要的作用，但也是北美最敏感和迅速衰退的动物群之一。由全球气候变化、工业排放、干旱或土地开发引起的水温上升可能会进一步挑战濒危的unionid社区。本研究的目的是确定淡水贻贝幼体（钩介）和幼体生命阶段的耐热上限。对8种贻贝的钩介虫进行了检测，它们是：长角蓝贻贝、翼眼溪蟹、直叶Ligumia recta、线叶椭圆藻、扁角藻、脉斑巨藻、曲张细齿藻和凹尾细齿藻。其中七个物种还在幼年时接受了测试。在标准急性实验室测试中，当贻贝在3种适应温度（17、22和27°C）下暴露于一系列普通和极端水温（20-42°C）时，监测存活趋势。在钩介虫24小时试验中，各物种的平均半数致死温度（LT 50）为31.6°C，范围为21.4 - 42.7°C。96小时幼龄动物试验的平均LT 50为34.7°C，范围为32.5 - 38.8°C。基于LT 50的比较，热耐受性不同种钩介，但不为青少年。驯化温度不影响任何生命阶段的耐热性。我们的研究结果表明，淡水贻贝在某些系统中可能已经接近它们的耐热上限，因此可能面临环境温度升高的风险。
Abstract Freshwater mussels (order Unioniformes) fulfill an essential role in benthic aquatic communities, but also are among the most sensitive and rapidly declining faunal groups in North America. Rising water temperatures, caused by global climate change, industrial discharges, drought, or land development, could further challenge imperiled unionid communities. The aim of our study was to determine the upper thermal tolerances of the larval (glochidia) and juvenile life stages of freshwater mussels. Glochidia of 8 species of mussels were tested: Lampsilis siliquoidea, Potamilus alatus, Ligumia recta, Ellipsaria lineolata, Lasmigona complanata, Megalonaias nervosa, Alasmidonta varicosa, and Villosa delumbis. Seven of these species also were tested as juveniles. Survival trends were monitored while mussels held at 3 acclimation temperatures (17, 22, and 27°C) were exposed to a range of common and extreme water temperatures (20–42°C) in standard acute laboratory tests. The average median lethal temperature (LT50) among species in 24-h tests with glochidia was 31.6°C and ranged from 21.4 to 42.7°C. The mean LT50 in 96-h juvenile tests was 34.7°C and ranged from 32.5 to 38.8°C. Based on comparisons of LT50s, thermal tolerances differed among species for glochidia, but not for juveniles. Acclimation temperature did not affect thermal tolerance for either life stage. Our results indicate that freshwater mussels already might be living close to their upper thermal tolerances in some systems and, thus, might be at risk from rising environmental temperatures.