Chopelet J, Blier P U, Dufresne F
Département de Biologie, Université du Québec à Rimouski, 300 Allée des Ursulines, Rimouski, Québec, Canada.
J Exp Zool A Ecol Genet Physiol. 2008 Nov 1;309(9):553-62. doi: 10.1002/jez.488.
The aim of this study was to evaluate the effect of temperature on growth and aerobic metabolism in clones of Daphnia magna from different thermal regimes. Growth rate (increment in size), somatic juvenile growth rate (increment in mass), and oxygen consumption were measured at 15 and 25 degrees C in 21 clones from one northern and two southern sites. There were no significant differences in body size and growth rate (increase in length) at both 15 and 25 degrees C among the three sites. Clones from southern site 2 had a higher mass increment than clones from the other two sites at both temperatures. Clone had a significant effect on growth (body length) and body size at both temperatures. As expected, age at maturity was lower at 25 degrees C (4.5 days) than at 15 degrees C, (11.6 days) and body sizes, after the release of the third clutch, were larger at 15 degrees C than at 25 degrees C. Northern clones had higher oxygen consumption rates and specific dynamic action (SDA) than southern clones at 15 degrees C. By contrast, southern clones from site 1 had a higher oxygen consumption and SDA than subarctic clones at 25 degrees C. Clones from southern site 2 had high oxygen consumption rates at both temperatures. Our results reveal important differences in metabolic rates among Daphnia from different thermal regimes, which were not always reflected in growth rate differences.
本研究的目的是评估温度对来自不同热环境的大型溞克隆生长和有氧代谢的影响。在15℃和25℃下，对来自一个北方地点和两个南方地点的21个克隆的生长速率（大小增加）、体细胞幼体生长速率（质量增加）和耗氧量进行了测量。在15℃和25℃时，三个地点的体长和生长速率（长度增加）没有显著差异。在这两个温度下，来自南方地点2的克隆的质量增量均高于来自其他两个地点的克隆。克隆在这两个温度下对生长（体长）和体型均有显著影响。正如预期的那样，25℃时的成熟年龄（4.5天）低于15℃时（11.6天），并且在释放第三批卵后，15℃时的体型大于25℃时。在15℃时，北方克隆的耗氧率和特殊动力作用（SDA）高于南方克隆。相比之下，在25℃时，来自南方地点1的克隆的耗氧量和SDA高于亚北极克隆。来自南方地点2的克隆在这两个温度下的耗氧率都很高。我们的结果揭示了来自不同热环境的大型溞在代谢率上的重要差异，这些差异并不总是反映在生长速率差异上。
