Bradley Richard
Department of Biology, University of New Mexico, 87131, Albuquerque, New Mexico, USA.
Oecologia. 1982 Dec;55(3):316-318. doi: 10.1007/BF00376918.
The desert grassland scorpion Paruroctonus utahensis spends most of its life in its burrow. During the active season, only about 5% of the individuals in a population appear on the surface each night. Individuals do not appear on the surface for several nights following a meal. To determine if physiological digestion time could account for this delay in reemergence after eating, I measured changes in oxygen consumption immediately following a meal. Oxygen consumption exceeded 125 μl Ogh just after completion of a meal, then dropped to normal levels (53 μl Ogh) within 6 h. I also measured the interval between completion of the meal and subsequent defecation. All individuals defecated by 72 h following ingestion (median 12 h). In field enclosures, scorpions returned to the surface after a mean of 20.3 days (median=16) following a successful predation event. Lack of correspondence between estimates of physiological digestion time and the reappearance interval lead me to reject the idea of a long digestive pause in Paruroctonus utahensis. This conclusion lends support to the hypothesis that scorpions remain in their burrows to minimize exposure to predation.
沙漠草原蝎子犹他州惧蝎大部分时间都生活在自己的洞穴里。在活跃季节，种群中每晚只有约5%的个体出现在地表。进食后的几个晚上，个体都不会出现在地表。为了确定生理消化时间是否能解释进食后再次出现的延迟，我测量了进食后立即出现的耗氧量变化。刚进食完，耗氧量超过125微升每克每小时，然后在6小时内降至正常水平（53微升每克每小时）。我还测量了进食结束到随后排便的间隔时间。所有个体在摄入食物后72小时内排便（中位数为12小时）。在野外围栏中，成功捕食事件后，蝎子平均在20.3天（中位数=16天）后回到地表。生理消化时间估计值与再次出现间隔时间之间缺乏对应关系，这使我拒绝了犹他州惧蝎存在长时间消化暂停的观点。这一结论支持了蝎子留在洞穴中以尽量减少被捕食风险的假说。
