Cabrera-Campos Iván, Carballo-Morales Jorge D, Saldaña-Vázquez Romeo A, Villalobos Federico, Ayala-Berdon Jorge
Maestría en Ciencias Biológicas, Centro Tlaxcala de Biología de la Conducta, Universidad Autónoma de Tlaxcala, Carretera Tlaxcala-Puebla Km. 1.5, C.P. 90062, Tlaxcala de Xicohténcatl, Tlaxcala, Mexico.
Laboratorio de Sistemática, Genética y Evolución (LabSGE), Escuela de Ciencias Biológicas, Universidad Nacional, Heredia, Costa Rica.
J Comp Physiol B. 2021 Mar;191(2):427-438. doi: 10.1007/s00360-021-01348-y. Epub 2021 Feb 11.
Bats are unique among mammals in that they have evolved the capacity to fly. This has generated strong selective pressure on the morphology and function of their digestive system. Given that in bats intestinal length and nominal surface-area are proportional to body mass, this trait importantly relates to explaining some of their digestive characteristics. We described the relationship between digestive traits and body mass of four species of bats of the family Vespertilionidae living in a montane ecosystem in central Mexico. We calculated food transit time, apparent dry matter digestibility, and defecation rate in feeding trials under captive conditions. We also: (1) built a model of the relationship between digestive traits and body mass to determine if this association was consistent within the members of the family Vespertilionidae, and (2) mapped these traits along the phylogeny to explore how digestive characteristics may have evolved. In our feeding trials, body mass was positively related to transit time and negatively related to apparent dry matter digestibility. The model predicted accurately the transit time in bats with body mass < 20 g. The phylogenetic approach suggested that over the evolutionary history of the family, transit time decreased as digestibility increased. Because of the results obtained here, it is likely that for most bats of the family Vespertilionidae, adaptations in digestive traits to process food have followed evolutionary changes in their body mass. We discuss these findings in a physiological and ecological context.
蝙蝠在哺乳动物中独一无二，因为它们进化出了飞行能力。这对其消化系统的形态和功能产生了强大的选择压力。鉴于蝙蝠的肠道长度和名义表面积与体重成正比，这一特征对于解释它们的一些消化特性至关重要。我们描述了生活在墨西哥中部山地生态系统中的四种植食性蝙蝠科蝙蝠的消化特性与体重之间的关系。我们在圈养条件下的饲养试验中计算了食物通过时间、表观干物质消化率和排便率。我们还：（1）建立了消化特性与体重之间关系的模型，以确定这种关联在食性蝙蝠科成员中是否一致，以及（2）沿着系统发育树绘制这些特征，以探索消化特性可能是如何进化的。在我们的饲养试验中，体重与通过时间呈正相关，与表观干物质消化率呈负相关。该模型准确预测了体重<20克的蝙蝠的通过时间。系统发育方法表明，在该科的进化历史中，随着消化率的提高，通过时间缩短。由于此处获得的结果，很可能对于食性蝙蝠科的大多数蝙蝠来说，消化特性对食物处理的适应遵循了它们体重的进化变化。我们在生理和生态背景下讨论了这些发现。
