Digestive tract measurements are often considered species specific, but little information exists on the degree to which they change during ontogeny within a species. Additionally, access to anatomical material from nondomestic species is often limited, with fixed tissues possibly representing the only available source, though the degree to which this material is representative in terms of dimensions and weight is debatable. In the present study, the macroscopic anatomy of the digestive tract (length of intestinal sections, and tissue weights of stomach and intestines) of 58 Lemur catta [ranging in age from 1 month (neonates) to 25 years], which had been stored frozen (n = 27) or fixed in formalin (n = 31), was quantified. Particular attention was paid to the caecum and the possible presence of an appendix. The intraspecific allometric scaling of body mass (BM)0.46[0.40;0.51] for total intestine length and BM0.48[0.41;0.54] for small intestine length was higher than the expected geometric scaling of BM0.33, and similar to that reported in the literature for interspecific scaling. This difference in scaling is usually explained by the hypothesis that, to maintain optimal absorption, the diameter of the intestinal tube cannot increase geometrically. Therefore, geometric volume gain of increasing body mass is accommodated for by more-than-geometric length scaling. According to the literature, not all L. catta have an appendix. No appendix was found in the specimens in the present study. The proportions of length measurements did not change markedly during ontogeny, indicating that the proportions of the foetus are representative of those of the adult animal. By contrast, width and tissue-mass scaling of the caecum indicated disproportionate growth of this organ during ontogeny that was not reflected in its length. Compared to overall intraspecific variation, the method of storage (frozen vs. formalin) had no relevant impact on length or weight measurements.

中文翻译：

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环尾狐猴（Lemur catta）的种内宏观消化解剖，包括冷冻和福尔马林储存标本的比较

消化道测量通常被认为是物种特异性的，但很少有关于它们在物种个体发育过程中变化程度的信息。此外，从非本地物种获取解剖材料通常是有限的，固定组织可能是唯一可用的来源，尽管这种材料在尺寸和重量方面的代表性程度是有争议的。在本研究中，58 只狐猴 [年龄从 1 个月（新生儿）到 25 岁不等] 的消化道宏观解剖结构（肠段长度、胃和肠组织重量）已被冷冻保存(n = 27) 或固定在福尔马林中 (n = 31)，被量化。特别注意盲肠和可能存在的阑尾。总肠道长度的体重 (BM) 0.46[0.40;0.51] 和小肠长度的 BM0.48[0.41;0.54] 的种内异速生长比例高于 BM0.33 的预期几何比例，与报道的相似在种间缩放的文献中。这种缩放比例的差异通常可以通过以下假设来解释：为了保持最佳吸收，肠管的直径不能以几何形式增加。因此，增加体重的几何体积增益通过超过几何长度缩放来适应。根据文献，并非所有 L. catta 都有附录。在本研究的标本中未发现附件。在个体发育过程中，长度测量的比例没有显着变化，表明胎儿的比例代表了成年动物的比例。相比之下，盲肠的宽度和组织质量缩放表明该器官在个体发育过程中不成比例地生长，这并未反映在其长度上。与整体种内变异相比，储存方法（冷冻与福尔马林）对长度或重量测量没有相关影响。