Norwegian Institute for Nature Research, NO-7485 Trondheim, Norway.
J Fish Biol. 2009 Jan;74(1):133-49. doi: 10.1111/j.1095-8649.2008.02119.x.
Using thermal growth data from eight populations of anadromous and lake-feeding brown trout Salmo trutta, hypotheses of adaptation to local optima and countergradient variation in growth were tested. The adaptation to local optima hypothesis suggests that natural selection can shift optimal performance temperatures to match the prevailing temperature in a new or changed thermal niche. In contradiction, the countergradient variation hypothesis suggests that populations from hostile environments perform better than conspecifics from benign environments at all temperatures. In this study, growth capacity varied between populations but there was no significant correlation between any of the estimated thermal performance parameters (e.g. lower and upper thermal growth limits, optimal temperature for growth and maximum growth capacity) and natural climatic conditions among populations. Hence, S. trutta growth response to temperature lends no support for either of the two suggested thermal adaptation hypotheses. Instead, growth capacity among populations tended to correlate positively with female size at maturity.
利用来自 8 个洄游和湖泊摄食型褐鳟 Salmo trutta 种群的热生长数据，检验了适应局部最优和生长反梯度变化的假说。适应局部最优假说认为，自然选择可以将最佳性能温度转移到与新的或改变的热生态位中的流行温度相匹配。相反，反梯度变化假说表明，来自恶劣环境的种群在所有温度下的表现都优于来自良性环境的同种个体。在这项研究中，生长能力在种群之间存在差异，但在任何估计的热性能参数（例如，较低和较高的热生长极限、生长的最佳温度和最大生长能力）与种群之间的自然气候条件之间都没有显著相关性。因此，S. trutta 对温度的生长反应不支持这两种建议的热适应假说中的任何一种。相反，种群之间的生长能力往往与成熟雌性大小呈正相关。
