Digestive System of Anourosorex squamipes - Appearance and Morphological Features
Authors: Liu Xiaodong , Zhang Yangkai , Yang Lulu , Zhao Huijuan , Wu Bangyuan 
Published: December 2024

Background: Anourosorex squamipes have a wide range of feeding habits, which is a kind of omnivorous animal. As an indispensable part of organisms, the differentiation degree of digestive system indicates the evolution degree of species. The higher the evolution degree of animals, the higher the differentiation of digestive system. At present, the research on Anourosorex squamipes digestive system mainly focuses on its feeding habits and mainly depends on the direct observation of gastric contents with the naked eye, but the research on the morphology of digestive system has not been reported.
Materials, Methods & Results: Twenty adult Anourosorex squamipes were selected to investigate the characteristics of the appearance, including the contour parameters (body weight, body length, forefoot length, posterior foot length, nasal length, tail length), digestive system parameters (length of esophagus, intestinal length, intestinal weight, stomach weight and liver weight) and morphological structure of the small intestine by histological methods. The results showed that there were no significant differences in body weight, body length, forefoot length, posterior foot length, nasal length and tail length between males and females in Anourosorex squamipes, and no significant differences were observed in parameters of digestive system in length of esophagus, intestinal length, intestinal weight, stomach weight and liver weight. There were no significant differences in villus height, muscular layer thickness and villus height/recess depth (V/C) between males and females, but only ileal crypt depth decreased significantly in males.
Discussion: Animal morphological characteristics are closely related to their life habits, unique organs and lifestyles ensure that they thrive on earth. In our study, we found that unique characters are found by observing the appearance of Anourosorex squamipes, the snout is blunt and short, the eyes are degenerated, and the tail is very short and covered with scales, which may be related to its feeding habits, the living environment-long-term nocturnal life in underground with minimal exposure to sunlight, and the unique tail can reduce the friction between tail and soil during the movement. There are certain differences in the appearance parameters of male and female Anourosorex squamipes, but are not significant. The esophagus, stomach, intestine, liver and other parameters of Anourosorex squamipes have little difference between males and females, indicating that Anourosorex squamipes don’t have obvious distinctions between males and females in food intake. However, the liver weight of male Anourosorex squamipes is larger than female, indicating that the physiological metabolic capacity of male is larger than female. It is speculated that this may be related to the difference in the amount of activity between males and females in daily life. Males are more active and require more energy, but their digestion and absorption abilities are weaker than females. Therefore, the male Anourosorex squamipes needs more food to provide energy to meet the daily physiological metabolism, and the larger stomach capacity provides the essential conditions for the male to store more food. In addition, we found that the crypt depth of male Anourosorex squamipes is generally greater than that of females, especially in the ileal crypt depth, indicating that the female’s cell maturation rate is greater than that of the male. It is speculated that the female has a greater demand for nutrient absorption and better digestion and absorption of food, because females need to give birth to offspring and require greater nutrition.
 
Keywords: Anourosorex squamipes, contour characteristics, digestive system, small intestine.