Abstract: Objective To investigate the community structure of parasitic fleas on the main rodents in Junggar Basin plague focus, and to analyze the role of each flea species in plague epizootiology. Methods The community structure factors, similarity, and clustering of parasitic fleas on rats in Junggar Basin were determined by community ecology methods. Results The community structures of parasitic fleas on Rhombomys opimus, Meriones meridianus, and Meriones erythrourus were the most complex, with the highest community richness, diversity, and relative rare species number, but without significant dominance. The parasitic fleas on Dipus sagitta had the second most complex community, with a community richness of 8, a mean rare species richness of 12.39 (the highest), a relative rare species number of 50.00%, and a diversity of 1.4838. The communities of parasitic fleas on Meriones tamariscinus and Allactaga sibirica were relatively complicated, with moderate homogeneity and advantages (both between 0.5 and 0.6), and both of them showed a species richness of 5, accounting for 31.25% of all flea species in the focus. In addition, they had mean species richness of 1.38 and 8.65 and relative rare species numbers of 20.00% and 40.00%. The community structures of parasitic fleas on Allactaga elater, Cricetulus griseus, Mus musculus, and Apodemus sylvaticus were simple, all with a relative rare species number of 0 and a mean species richness below 1.00. A. sylvaticus had only 1 species of flea, and the parasitic fleas on A. elater, C. griseus, and M. musculus had community richness of 2-4. The mean value of similarity index between the parasitic fleas on Rh. opimus, M. meridianus, M. erythrourus, D. sagitta, A. elater, C. griseus, and A. sylvaticus and other rats was greater than 0.5, and the mean value of similarity index between the communities of parasitic fleas on M. tamariscinus, A. sibirica, and M. musculus and other rats was less than 0.5. The communities of parasitic fleas on M. meridianus and other rats showed the highest similarity, with a mean value of similarity index of 0.6836, and the similarity index between the communities of parasitic fleas on M. meridianus and 7 species of rats was greater than 0.6, followed by the parasitic fleas on Rh. opimus and D. sagitta, which demonstrated a similarity index greater than 0.5, as compared with those on 6 species of rats. The similarity index between the communities of parasitic fleas on A. sibirica and other rats was the lowest (all below 0.5). The parasitic fleas on M. musculus showed a similarity index greater than 0.5 only when compared with those on M. erythrourus and M. tamariscinus, and had a mean value of similarity index of 0.2812 when compared with the fleas on other rats. The communities of parasitic fleas on the 10 species of rats were clustered into 3 phylogenetic branches (the communities on Rh. opimus, M. tamariscinus, and M. erythrourus, the communities on M. meridianus, and the communities on D. sagitta, A. sibirica, A. elater, M. musculus, A. sylvaticus, and C. griseus). Conclusion The fleas on rodents in the Junggar Basin plague focus exist in complex ecological communities. The communities of fleas on Rh. opimus, M. meridianus, and M. erythrourus are dominant in maintaining the complexity and diversity of fleas, while the communities of fleas on A. elater, C. griseus, A. sylvaticus, and M. musculus are complementary. There is extensive exchange of fleas among the rats in this region, and the fleas on M. meridianus are a key factor for the exchange. Rh. opimus and its fleas play a key role in plague epizootiology in the focus, and M. meridianus and its fleas may promote the prevalence of animal plague.

Key words: Plague, Natural focus, Flea, Community, Junggar Basin

摘要： 目的 了解和掌握准噶尔盆地鼠疫自然疫源地主要鼠类体外寄生蚤类的群落结构,分析各鼠体蚤在该疫源地动物鼠疫流行中的作用。方法 采用群落生态研究方法对准噶尔盆地各鼠体蚤类群落进行群落结构因子、相似性和聚类研究。结果 大沙鼠、子午沙鼠和红尾沙鼠体外寄生蚤群落最复杂,体外寄生蚤群落的丰富度、多样性、相对稀有种类数高,优势度不明显;其次为三趾跳鼠体外寄生蚤群落,丰富度为8,平均稀有种类丰富度最大为12.39,相对稀有种类数、多样性次之,分别为50.00%和1.4838;柽柳沙鼠、西伯利亚五趾跳鼠体外寄生蚤群落相对较为复杂,均匀性、优势度适中,在0.5～0.6之间,种类丰富度均为5种,占该疫源地蚤种类数的31.25%,平均种类丰富度分别为1.38和8.65,相对稀有种类数分别为20.00%和40.00%。小五趾跳鼠、灰仓鼠、小家鼠和小林姬鼠体外寄生蚤群落结构简单,相对稀有种类数均为0,平均种类丰富度均在1.00以下,小林姬鼠仅有1种蚤类;另3种鼠体寄生蚤群落丰富度在2～4之间;大沙鼠、子午沙鼠、红尾沙鼠、三趾跳鼠、小五趾跳鼠、灰仓鼠和小林姬鼠7种鼠类体外寄生蚤群落与其它鼠类寄生蚤相似性指数均值>0.5,柽柳沙鼠、西伯利亚五趾跳鼠和小家鼠3种鼠体寄生蚤群落与其它鼠类寄生蚤相似性指数均值<0.5;其中,子午沙鼠体蚤群落与其它鼠类寄生蚤群落的相似性均值最高,为0.6836,与7种鼠类寄生蚤群落的相似性>0.6;其次是大沙鼠和三趾跳鼠体蚤群落,与6种鼠类体外寄生蚤群落相似性>0.5;西伯利亚五趾跳鼠体外寄生蚤群落与其它鼠类寄生蚤群落的相似性最小,均<0.5;小家鼠仅与红尾沙鼠和柽柳沙鼠体蚤群落的相似性>0.5,相似性指数均值为0.2812;10种鼠类体外寄生蚤群落可聚类为3个系统支,分为大沙鼠、柽柳沙鼠和红尾沙鼠体蚤群落支,子午沙鼠体蚤群落支和三趾跳鼠、西伯利亚五趾跳鼠、小五趾跳鼠、小家鼠、小林姬鼠和灰仓鼠体蚤群落支。结论 准噶尔盆地鼠疫疫源地鼠体蚤类群落是一个复杂的生态群落,大沙鼠、子午沙鼠、红尾沙鼠体蚤群落在维持该疫源地蚤类复杂性和多样性方面居第一层次,小五趾跳鼠、灰仓鼠、小林姬鼠和小家鼠体蚤群落起补充作用;该地区鼠体间蚤类存在广泛交换,子午沙鼠体蚤群落是各鼠体蚤类群落间相互交换的关键因子;大沙鼠及其体蚤在该疫源地动物鼠疫流行中起关键作用,子午沙鼠及其体蚤群落对动物鼠疫的流行有扩散作用。

关键词: 鼠疫, 自然疫源地, 蚤类, 群落, 准噶尔盆地