Wehrle Beck A, German Donovan P
Department of Ecology and Evolutionary Biology, University of California, Irvine, CA 92697, USA; Department of Biology, Bryn Mawr College, 101 N. Merion Ave, Bryn Mawr, PA 19010, USA.
Department of Ecology and Evolutionary Biology, University of California, Irvine, CA 92697, USA. Electronic address: https://twitter.com/dgermanuci.
Comp Biochem Physiol A Mol Integr Physiol. 2023 Mar;277:111369. doi: 10.1016/j.cbpa.2023.111369. Epub 2023 Jan 14.
Digestion and assimilation of nutrients and energy is central to survival. At its most basic level, investigations of digestion in animals must examine digestive efficiency, or how much of a given meal (i.e., energy) or a specific nutrient an organism can acquire from its food. There are many studies examining this in reptiles, but there is large variation in methodology, and thus, in the conclusions drawn from the gathered data. The majority rely on ratio-based analyses that can jeopardize the reliability of their findings. Therefore, we reviewed the literature to identify common themes in the digestive efficiency data on reptiles. Due to the sheer number of available studies, we largely focused on lizards, but included data on all reptilian groups. As an example of what the current data can reveal, we performed a meta-analysis of digestive efficiency in lizards as a function of temperature using regression analyses. We detected a weak positive trend of soluble carbohydrate digestibility as a function of temperature, but no similar trend in broad-scale digestive efficiency, and propose that these patterns be reevaluated with non-ratio data. We conclude with calls to end conducting analyses on ratios and instead employ covariate methods, for more studies of reptilian digestive efficiency and related processes using consistent methodology, more representation of each population (e.g., many studies focus on males only), and more detailed studies examining the effects of temperature on digestion (since the current data are inconclusive).
营养物质和能量的消化与吸收是生存的核心。在最基本的层面上，对动物消化的研究必须考察消化效率，即生物体从食物中获取给定一餐（即能量）或特定营养素的量。有许多研究在爬行动物中对此进行了考察，但方法存在很大差异，因此，从收集到的数据得出的结论也存在差异。大多数研究依赖基于比率的分析，这可能会损害其研究结果的可靠性。因此，我们回顾了文献，以确定爬行动物消化效率数据中的共同主题。由于现有研究数量众多，我们主要关注蜥蜴，但也纳入了所有爬行动物类群的数据。作为当前数据所能揭示内容的一个例子，我们使用回归分析对蜥蜴消化效率随温度的变化进行了荟萃分析。我们检测到可溶性碳水化合物消化率随温度呈微弱的正趋势，但在广泛的消化效率方面没有类似趋势，并建议用非比率数据重新评估这些模式。我们最后呼吁停止进行比率分析，转而采用协变量方法，以便使用一致的方法对爬行动物的消化效率及相关过程进行更多研究，对每个种群有更多代表性（例如，许多研究仅关注雄性），以及进行更详细的研究来考察温度对消化的影响（因为目前的数据尚无定论）。
