Britton David K, McMahon Robert F
Department of Biology, Box 19498, University of Texas at Arlington, Arlington, Texas 76019, USA.
Physiol Biochem Zool. 2004 Mar-Apr;77(2):187-96. doi: 10.1086/381469.
Allocation of organic carbon (OC) to primary energetic pathways was estimated under seasonal and artificially elevated ambient temperatures for a field population of a freshwater pulmonate snail, Physella virgata. Allocation to respiration increased with temperature. Snails allocated most assimilated OC to reproduction within their natural temperature range (15 degrees -35 degrees C), where assimilation efficiencies remained relatively stable at 25%-35%. However, in artificially heated waters exceeding 35 degrees C, declining assimilation rates and increasing respiratory demands inhibited allocation to reproduction and growth. At the species' 40 degrees C upper thermal limit, assimilation efficiencies fell below 10%, while average consumption levels more than doubled relative to snails unaffected by the thermal effluent. Ambient temperature substantially influenced OC allocation over P. virgata's natural temperature range and negatively affected growth and reproduction at temperatures approaching or exceeding maximum natural levels.
在季节性和人为升高的环境温度下，对淡水肺螺蜗牛（Physella virgata）的野外种群进行了有机碳（OC）向主要能量途径分配的估算。向呼吸的分配随温度升高而增加。在其自然温度范围（15摄氏度至35摄氏度）内，蜗牛将大部分同化的有机碳分配给繁殖，在此温度范围内同化效率保持相对稳定，为25%至35%。然而，在超过35摄氏度的人工加热水域中，同化率下降和呼吸需求增加抑制了对繁殖和生长的分配。在该物种40摄氏度的热上限时，同化效率降至10%以下，而相对于未受热废水影响的蜗牛，平均消耗水平增加了一倍多。环境温度在Physella virgata的自然温度范围内对有机碳分配有显著影响，并且在接近或超过自然最高水平的温度下对生长和繁殖产生负面影响。
