高寒地区高原鼢鼠消化道形态的季节变化

SEASONAL VARIATIONS IN GASTROINTESTINAL TRACT MORPHOLOGY IN PLATEAU ZOKOR (MYOSPALAX BAILEYI)

对青海高原地区的高原鼢鼠在自然环境中消化道各器官的长度及重量的季节变化进行了测定 ,结果显示总消化道保持相对的稳定性 ,长度、鲜重及干重均相对稳定 ,而含内容物器官重季节性变化明显。胃的变化相对较稳定 ,但长度季节性变化显著 ,草枯黄期值最高 ,草生长盛期最低 ;小肠的鲜重在草返青期明显低于草生长盛期和草枯黄期 ;盲肠的变化最大 ,其长度和含内容物器官重草返青期明显高于其它季节。大肠的干重于枯黄期显著增加。各器官的所有其它指标则保持相对稳定。说明终生营地下生活的高原鼢鼠由于其洞道系统的气候条件相对稳定 ,又具有贮存食物的习性 ,因而在自然条件下消化道形态的调节并不强烈 ;但面对各种生态因素的影响各器官在某些方面又进行一些调节 ,以提高消化效率。本研究支持关于高原鼢鼠在自然条件下其消化道维持相对稳定的假设。

The seasonal changes in digestive tract morphology in a fossorial rodent—plateau zokor ( Myospalax baileyi ) from Qinghai Tibet Plateau was determined No significant seasonal variations were found in length, wet and dry weight except the weight with content for total gut For the separate organs of the gut, only length in stomach, wet weight of small intestine, dry weight of large intestine, and length and weight with contents of caecum, showed significant seasonal changes Caecum is the organ which showed the most dramatically seasonal variations All other measures of the different organs of the digestive tract were kept relative stable This suggested that no markedly seasonal adjustment in gastrointestinal tract in plateau zokor, which lived fossorial with constant climate conditions of their burrowing system and with the habit of storing food, in the field conditions However, in order to increase their digestive efficiency, some organs showed some seasonal adjustments under the stress of some ecological factors such as cold, lactation and lower quality of food. This study supported the hypothesis that plateau zokor kept their gut capacity stable in the natural environment.