洞庭湖区社鼠消化道长度和质量的季节变化

对洞庭湖区社鼠（Niviventer confucianus）自然种群四季的消化道各器官的长度和质量进行了测定。结果表明。消化道指标季节变化明显。总体消化道含内容鲜质量、净鲜质量与干质量均具有显著的季节变化。以冬、春季较高。夏、秋季较低。消化道各器官的变化与总消化道不尽相同。其中，以胃的变化相对比较稳定。仅长度的变化达显著水平，以冬季最短，夏、秋季较长。这是动物为适应繁殖季节能量需求而增加摄食量的反应，也与夏秋季食物丰富度有关。小肠、盲肠、大肠的长度和质量指标（内容鲜质量、净鲜质量和干质量）以冬、春季较高。夏、秋季较低。这是该鼠对冬、春季低温和食物匮乏的适应性反应。总体来说。洞庭湖区社鼠为适应夏、秋季繁殖盛期能量需求增加的主要对策是增加摄食量；而为适应冬、春季低温环境和食物数量和质量减少的主要对策是增大消化道。提高消化效率。

Seasonal variations of digestive tract length and weight of Niviventer confucianus in Dongting Lake region

The study showed that there existed obvious seasonal variations in the digestive tract length and weight of Niviventer confucianus in Dongting lake region. The fresh weight of digestive tract with contents and the fresh and dry weights of the tract without contents were higher in winter and spring than in summer and autumn. As for different organs of the tract, stomach showed significant seasonal variation of its length, being the shortest in winter and longer in summer and autumn, which was the response of N. confucianus to take more food to fit the energy needs for reproduction and to meet the abundant food in summer and autumn. The length, fresh weight with and without contents, and dry weight without contents of other organs (small intestine, caecum and large intestine) were larger in winter and spring than in summer and autumn, an adaptive response to the low temperature and food deficiency in winter and spring. It was suggested that N. confucianus had strong capability in adjusting its gastrointestinal volume and size to adapt to the seasonal changes of ambient temperature and food resources.