【作者】 黄丽琴；

【导师】 郭宪国；

【作者基本信息】 大理学院 ， 病原生物学， 2010， 硕士

【摘要】 目的：系统研究小型哺乳动物(小兽)体表寄生的医学革螨在云南省不同地域的流行分布状况,并在此基础上进行革螨群落特征(革螨群落物种组成及物种多样性、群落基本结构、空间分布格局、小兽样本最小抽样量确定与群落内总物种数预测等)的进一步研究,以揭示医学革螨流行分布和群落结构方面的规律性,为医学革螨的其它基础和应用研究、媒介革螨及螨媒传染病的监测和控制等提供资料参考和理论依据。材料与方法：(1)原始数据资料来源于1990～2008年18年间对云南省境内28个县(市)的现场抽样调查。在动物地理上,这28个县市隶属于东洋界、中印亚界2个区(西南区和华南区)、2个亚区(西南山地亚区和滇南山地亚区)中的5个小区,即：Ⅰ横断山中部小区；Ⅱ横断山南部小区；Ⅲ滇东高原小区；Ⅳ西高原小区和V滇南山地小区。(2)用主成分分析方法分析影响革螨分布的主要因素。(3)群落结构用构成比Cr、物种丰富度S、Simpson优势度指数D、Shannon多样性指数H、Pielou均匀度指数E、感染率P、平均丰富度MA计算。(4)运用物种数、平均丰富度和Shannon多样性指数对小兽寄生革螨的群落特征和沿环境梯度(经纬度和海拔)的空间分布进行研究。(5)选择云南省18种主要小兽宿主体表革螨群落为分类单元,用系统聚类法(SPSS16.0软件)对18种主要小兽的革螨群落相似性进行比较。(6)选择捕获量较大的小兽为研究对象,运用生态学中的“种一面积”关系理论,拟合特定种类小兽个体捕获数量(样本量)与革螨种类数之间的“种一样方’关系曲线,确定革螨群落研究中的最小样方数量,即小兽样本量。(7)采用Chao 1公式进行革螨群落总物种数预测。(8)将云南省28个县市捕获的67种小兽宿主作为67级资源序列,30种主要革螨在67种小兽宿主体表的分布数量构成比作为其各级资源的利用比例,采用Levins和Colwell-Futuyma模型测定30种革螨的生态位宽度、生态位重叠,并用系统聚类法进行生态位重叠群的划分,探讨30种主要革螨与相应小兽的协同进化关系。结果：(1)共捕获小兽14544头,分类鉴定为5目(啮齿目、食虫目、攀购目、兔形目、食肉目)10科35属67种。从捕获的小兽体表共采集到革螨80791只,经分类鉴定,隶属于10科33属112种。黄胸鼠(Rattus tanezumi)、齐氏姬鼠(Apodemus chevrieri)和大绒鼠(Eothenomys miletus)是云南省28个县市的优势小兽种类；纳氏厉螨(Laelaps nuttalli)、毒厉螨(Laelaps echidninus)和贵州厉螨(Laelaps guizhouensis)为革螨的优势种；(2)横断山中部小区的小兽和革螨相对其它小区种类较丰富,多样性指数较高；(3)15种主要医学革螨的螨密度(螨指数)在不同纬度和海拔的分布格局大致相同；(4)革螨及其小兽宿主物种丰富度和多样性的空间分布趋势均表现出随着纬度和海拔的升高而先升高后降低的单峰型分布格局,峰值分别出现在北纬26°-27°N和海拔2000-2500m之间；(5)大部分革螨群落的相似性大小与相应小兽在分类地位上的近缘性高低基本一致。分类地位和生境选择相似的小兽,它们体表的革螨群落相似性较高。(6)以样本数量较大的黄胸鼠为代表,在成功拟合“种一样方”曲线的基础上,确定小兽(黄胸鼠)样本的最小抽样量为2050只；(7)根据chao 1公式,初步估测出黄胸鼠体表革螨的物种数为66种。(8)大部分革螨的宿主范围较宽(2～31种),但只在某种或某几种主要宿主体表的分布数量大,其生态位宽度值也并不高(0.0154～0.1646),革螨两两之间生态位均有不同程度的重叠,但重叠指数不高。经系统聚类,30种革螨在λ=5.0的位置被分成15个生态位重叠群。结论：(1)云南省医学革螨的种类丰富,物种多样性高。革螨的分布与云南省独特的地形地貌、生态景观和气候特点及小兽宿主的分布状况和多样性密切相关。毒厉螨、纳氏厉螨、特氏厉螨、柏氏禽刺螨、鼢鼯赫刺螨和土尔克厉螨等是云南省的广布种和广宿主种；柳氏厉螨、贫毛厉螨、贵州厉螨、兴义厉螨、短尾鼠鼩地厉螨、阿尔及利厉螨、松鼠真厉螨、上海真厉螨属于云南省的狭布种和窄宿主种；景东厉螨和三峡血革螨属于横断山中部小区的特有种。广布种和广宿主种革螨传播疾病的媒介潜能较大,可能在鼠-人间传播和鼠-鼠间传播HFRS和维持疫源地方面起重要作用。(2)云南省小兽体表革螨群落多样性较高,结构复杂,其相似性受到小兽宿主分类地位和宿主所处生态环境双重因素的影响。(3)云南省小兽和革螨多样性的空间分布格局均表现为随纬度和海拔升高先增高后降低的单峰形分布格局,峰值分别出现在北纬26°～27°N和海拔2000～2500m之间。这种多样性的分布格局可能直接受到古北和东洋两区系“边缘效应”的影响。革螨的水平分布格局近似于它们的垂直分布格局。(4)云南省小兽体表革螨群落物种组成和群落结构因宿主动物所处的地域和生境不同而差异较大。小兽体表革螨群落的“种-样方曲线”达到平台期需要较大的小兽样本。(5)多数的革螨宿主特异性较低,只有部分革螨的宿主特异性比较高。虽然大部分革螨可选择寄生于多种宿主体表,但它们都有各自相对稳定的主要小兽宿主种类,革螨与主要小兽宿主之间存在一定程度的协同进化关系,但程度还不是很高。更多还原

【Abstract】 Objectives:To provide the guideline for the surveillance and control of vector mites and some mite born diseases, the prevalent distribution and community characteristics of medical gamasid mites on the body surface of small mammals were investigated in Yunnan Province of China, which covered the species composition and species diversity of gamasid mite community, the basic structure of the community, spatial patterns of the communities in different geographical areas, the determination of minimum host (small mammal) samples and the estimation of total mite species on the basis of illustrating the prevalent distribution patterns of gamasid mites.Materials and Methods:(1) The original data came from the field investigation in 28 counties of Yunnan Province from 1990 to 2008. The 28 investigated counties belong to the five microsubregions of two subregions (Southwestern Mountainous Subregion and South Mountainous Subregion of Yunnan) within two regions (Southwestern Region of China and South Region of China) in Sino-Indian Subrealm of Oriental Realm in zoogeography. These five microsubregions are namelyⅠMiddle Microregion of Hengduan Mountains,ⅡSouthern Microregion of Hengduan Mountains,ⅢEastern Plateau Microregion of Yunnan, IV Western Plateau Microregion of Yunnan and V Southern Mountainous Microregion of Yunnan. (2) The Principal Component Analysis (PC A) was used to analyze the main factors that influenced the prevalent distribution of medical gamasid mites. (3) The constituent ratio (Cr), species richness (S), Simpson’s dominance index (D), Shannon diversity index (H), Pielou evenness (E), prevalence (P) and mean abundance (MA) were used to measure the community structure. (4) The community characteristics and the spatial distribution of gamasid mites along the geographical gradients (longitudes, latitudes and altitudes) were described by using species richness, Shannon diversity index and mean abundance. (5) The gamasid mites on 18 main species of small mammal hosts were defined as 18 gamasid mite communities. Based on hierarchical clustering analysis, the similarity of 18 mite communities was compared with SPSS 16.0 software. (6) Based on the "species-area" relationship theory in ecology, the small mammal species captured with large number was selected as the object and a "species-sampling" curve of gamasid mites and their hosts was fitted to determine the minimum sampling small mammal hosts. (7) Chao 1 richness estimator (Chao 1984) was used to estimate the total species richness of gamasid mite community. (8) All the 67 species of small mammals captured from 28 counties were regarded as 67 series of host resources and the individuals of each species of gamasid mites on 67 species of small mammals were calculated into constituent ratios in 67 host resource series. Levins’ and Colwell-Futuyma’s methods were used to measure the niche breadth and niche overlap respectively. The hierachical analysis in SPSS 16.0 statistical software was used to classify the mite communies into different niche overlaping groups to evaluate the ecological coevolution between the gamasid mites and their corresponding hosts.Results:(1) A total of 14 544 individuals of small mammals were captured and identified as 10 families,35 genera and 67 species in five orders (Rodentia, Insectivora, Scandentia, Lagomorpha and Carnivora). From the body surface of captured small mammal hosts,80 791 individuals of gamasid mites were collected and they were identified as 10 families,33 genera and 112 species. The results indicated that the dominant host species were Rattus tanezumi, Apodemus chevrieri, and Eothenomys miletus, while the dominant gamasid mite species were Laelaps nuttalli, L. echidninus and L. guizhouensis. (2) The results showed that the mites and small mammals are higher in species richness and diversity indices in the Middle Micro-region of Hengduan Mountains than in other geographical micro-regions. (3) The spatial density distribution of 15 dominant gamasid mite species along latitudinal and altitudinal gradients showed a similar pattern. (4) The species richness and diversity patterns of gamasid mites and their small mammal hosts presented a similar trend of single-peak curves, which increased and then decreased gradually with the increase of latitude and elevation, peaking at the latitude 26°N to 27°N and the elevation of 2000 m to 2500 m. (5) The similarity of most gamasid mite communities were in accordance with the taxonomic relationship and the habitats of their corresponding small mammal hosts. The gamasid mite communities are clustered into the same group when their hosts are similar in zoological taxonomy and habitat selection. (6) A species-plot relation curve of gamasid mites and their hosts was successfully made, and the median of the curve which representing 2050 individuals of R. tanezumi was determined as the minimum rat samples. (7) According to the estimation of species richness, the total species of gamasid mites on R. tanezumi were estimated to be 66 species. (8) Most of the mites can parasitize a wide range of host species (2～31), but they usually achieve more individual abundant on certain dominant host species, their niche breadths ranged from 0.0154 to 0.1646. Most species of gamasid mites showed a relatively low niche overlaps between every two of them. Based on the hierachical clustering analysis, the 30 species of gamasid mites studied were classified into 15 niche overlapping groups whenλ= 5.0 in the clustering dendrogram.Conclusions:(1) The species of medical gamasid mites are very rich in Yunnan Province with high biodiversity. The distribution of gamasid mites are closely related to the unique topography, ecological landscape and climate features and the distribution and diversity of small mammal hosts. Among the species recorded during the investigations, Laelaps echidninus, L. nuttalli, L. traubi, Ornithonyssus bacoti,Hirstionyssus sunc, L turkestanicus are wide-distributed and multi-host mite species; L. liui, L.paucisetosa, Lguizhouensis, L.xingyiensis, Dipolaelaps anourosorecis, Lalgericus, Eulaelaps dremomydis and E. shanghaiensis are narrow-distributed and narrow-host mite species; L. jingdongensis and Haemogamasus sanxiaensis are endemic species of Middle Microregion of Hengduan Mountains. The wide-distributed and multi-host mite species are potential vectors in the transmission of mite-borne diseases, which may play a key role in rat-human and rat-rat transmission and the maintenance of foci of HFRS. (2) The community structure of gamasid mites on small mammals in Yunnan is extremely complicated with high biodiversity. The similarity of gamasid mite communities are influenced by both the taxonomy status and the habitats of their hosts. (3) The diversity spatial distribution patterns of gamasid mites and their small mammal hosts showed the similar trends of single-peak curves which gradually increased and then decreased with increasing of latitude and elevation, peaking at latitude 26°N to 27°N and the elevation of 2000 m to 2500 m. The spatial distribution patterns of gamasid mites in Yunnan Province may be the results of the "edge effect" between the Oriental and Palaearctic realms. The horizontal and vertical distribution patterns of gamasid mites are similar. (4) The species composition and community structures of gamasid mite on small mammals in Yunnan varied with the variation of the regions and the habitat types of their hosts. To reach the plateau phase of "species-sampling" curve of gamasid mites and their hosts, a larger samples of small mammals is needed. (5) Except for a few mite species which have high host specificity, the majority of the mite species have low host specificity. Although most of the mites can parasitize a wide range of host species, they usually have some relatively fixed dominant hosts, which suggest that some coevolutionary relationship may exsist between gamasid mites and their small mammal hosts, but the degree is not very high.更多还原