甘肃仓鼠的分类地位

自1928年Allen发表采自甘肃卓尼的甘肃仓鼠(Cansumys canus)以来,对其分类地位的争论就没有停止,不同学者从形态学和生态学方面研究得出了不同的结论。为了确认Allen所命名的甘肃仓鼠的分类地位,本研究利用形态性状和遗传性状,比较研究了甘肃、宁夏标本(包括模式产地标本)与华北、东北大仓鼠标本共计169只。结果显示:甘肃、宁夏地区标本身体及头骨量度与大仓鼠指名亚种、东北亚种间大多无显著性差异;地理分布连续,其间无隔离,也无地理重叠;生态特征与华北、东北的大仓鼠相似;基于线粒体DNA D-loop区序列的遗传变异分析表明,甘肃、宁夏地区种群与大仓鼠东北亚种种群关系较大仓鼠东北亚种种群与指名亚种种群关系更近;单倍型演化关系显示,指名亚种种群和东北亚种种群分别独立地由甘肃种群单倍型衍生而来,并且三个种群单倍型之间的分歧较浅,没有形成种上的分歧程度。据此,甘肃、宁夏地区“甘肃仓鼠”应为大仓鼠甘肃亚种[Cricetulus triton canus(Allen),1928]。

Taxonomic status of Cansumys canus (Allen,1928)

Taxonomic status of Cansumys canus has been widely debated since 1928 when it was first reported by G.M.Allen.We compared the morphological and genetic differences of 169 specimens of greater long-tailed hamster Cricetulus triton collected from Gansu Province(including Zhuoni County where the type specimen was collected),Ningxia Hui Autonomous Region,North China Plain and Northeast China Plain.The results show that there are very little morphological and genetic differences between specimens from Gansu Province and Ningxia Hui Autonomous Region and those from North China Plain and Northeast China Plain.The distribution of specimens from Gansu Province and Ningxia Hui Autonomous Region is continuous without gap or overlap with the neighboring subspecies.Analysis of mtDNA D-loop indicates that the relationship between Gansu-Ningxiat population and C.t.fuscipes is closer than that between population of C.t.triton and C.t.fuscipes.In general,our result supports that Cansumys canus should be listed as a subspecies,Cricetulus triton canus,instead of a species.