中华蟾蜍静止代谢率与高耗能器官大小的关系

Association Between Resting Metabolic Rate and Energetically-Expensive Organ Size in Bufo gargarizans

摄食增量假说认为,持续能量支出与静止代谢率正相关,且需要较大的高耗能器官(心脏、肝脏、肾脏和小肠等)与其匹配。因此,该假说预测静止代谢率与高耗能器官质量正相关。该预测在脊椎动物种间研究中得到普遍支持,但在种内研究中的结论尚不一致。在外温动物中的种内验证尤其缺乏。本研究以中华蟾蜍Bufo gargarizans为研究对象,采用重复测量的研究范式分解静止代谢率的个体间方差,并与高耗能器官的相对大小进行关联分析。结果显示二者并无相关性。这说明静止代谢率与高耗能器官大小的相关性在外温动物种内研究中不具普遍性,不支持摄食增量假说。

Food-intake increased hypothesis argues that higher sustained energy output requires larger energetically-expensive organs(heart,liver,kidney,and intestines etc.)to convert ingested food into useable energy,and this process is positively associated with resting metabolic rate(RMR).It is predicted that RMR might also be positively associated with the mass of energetically-expensive organs,and this is strongly supported in the study of interspecific vertebrate species.However,the association of RMR and the mass of energetically-expensive organs is unclear in the population of homogeneous vertebrates,especially in the intraspecific studies of ectotherms.In this study,we analyzed the associations between the sizes of energetically-expensive organs and RMR of Bufo gargarizans using repeated-measure,which was designed to separate inter-individual from intra-individual variances.However,no correlation between the two traits was identified.Therefore,the positive correlation between the sizes of energetically-expensive organs and RMR is not a universal phenomenon in ectotherms,and does not accord to the food-intake increased hypothesis.