洞庭湖不同生态类型区黑线姬鼠消化道重量和长度的季节变化

对洞庭湖3种不同生态类型区(农区、林区、农林交错区)不同季节黑线姬鼠消化道各器官长度、鲜重和干重的测量表明，在3种生态类型区中，黑线姬鼠消化道各器官鲜重和干重季节变化显著。农区和林区消化道各器官的鲜重和干重在春季和冬季显著重于夏季和秋季，农林交错区消化道各器官鲜重和干重在春季显著重于夏季和秋季，这可能与春季和冬季黑线姬鼠能量需求增加、食物缺乏和食物质量下降有关。在同一季节，3种生态类型区之间消化道各器官长度、鲜重和干重均无显著性差异。这与3种生态类型区间黑线姬鼠食物变化较小有关。关于消化道各器官长度变化方面，除了农区的大肠长度有显著季节性差异外，其它指标均无显著季节性差异。以上结果表明黑线姬鼠消化道各器官在外界环境因素的影响下能产生不同的反应，消化道形态的变化是黑线姬鼠面临外界胁迫因子时的一种消化对策。

Seasonal Changes in Weight and Length of Digestive Tract of Striped Field Mouse (Apodemus agrarius) in Three Ecosystems in Dongting Lake Region

The length, fresh weight and dry weight of stomach, small intestine, caecum and large intestine of striped field mice (Apodemus agrarius) in farmland, in forest and in the interlaced region between forest and farmland in different seasons were measured. The results showed that fresh weight and dry weight of the digestive tracts of the animals varied significantly in different seasons. All the fresh weight and dry weight of digestive organs were significantly greater in winter and in spring when the food supply was relatively short. These were presumably related to the increase of energy needs, deficient food and the food with low quality. However, the changes of the digestive tracts (weight or length) in different habitats were not significant in same season. The authors considered that it may be because of the similar food supplies in the three habitats. In addition, the differences of the length of the digestive tracts of striped field mice in different habitats or different seasons were not significant except the fresh weight of large intestine in farmland. The results of our research indicated that the morphological modification of the digestive tracts of striped field mice could adapt their living environments.