根田鼠消化道长度和重量的变化及其适应意义

动物消化道的形态与食性、食物质量以及动物量的需求密切相关。本文对青海高原地区的根田鼠在自然环境中消化道各器官的长度及重量进行了测定，结果显示总消化道及各器官（胃、小肠、大肠和盲肠）的长度，含内容物重（鲜重和干重）在各物侯期间具显著的变化，各项指标均于环境条件较好的植物生长盛期最低，于条件较差（食物纤维素含量高及低温）的植物枯黄期或返青期较高。各器官所反应程度不同，其中小肠的反应最为强烈，表明消化道

VARIATIONS IN DIGESTIVE TRACT MORPHOLOGY IN ROOT VOLE(MICROTUS OECONOMUS)AND ITS ADAPTIVE SIGNIFICANCE

The animal gut morphology is closed related to food habit,food quality and energyneed.The seasonal changes in length and weight of total and separate organs ofdigestive tract in root vole(Microtus oeconomus),which lived in Qinghai-Tibetanplateau,was determined.It was showed that the length,weight of with content,emptyand dry tissues of total and every organsstomach,small intestine,large intestine andcaecum)of root vole gut had significant seasonal variations. Each index was the lowestin excuberance period,which is moderate to vole,while in green up and/or whitheringperiod,which the fiber content is high in food and temperature is low,all indexes werehigher.The responsive magnitude of each organ was different and the small intestineresponded strongly to the seasonal acclimatization,This suggested that the adjustmentin morphology and capacity of digestive tract is important in animal's digestivestrategies.Different organs showed different responses to different stress,similarly,different pressure have a different effect to the digestive tract. Our results indicated thatroot vole have the ability physiologically to adapt the high-fiber food and lowtemperature environment in their natural habitats.