Study On Fauna And Species Diversity Of Tardy Fauna In Liupan Mountain Region

Tardigrade fauna and species diversity of the Liupanshan Mountains,China were studied.Tardigrade,commonly called "water bear",belongs to an independent Phylum Tardigrada.They are microscopic hydrophilous invertebrates with body lengths usually between 0.05-1.2 mm.Phylogenetically,tardigrade is the sister group to the monophyletic Panarthropoda which includes the arthropods and Onychophora.Over 1,200 species/subspecies have been described,of which,more than 200 species/subspecies were found in China.The Liupanshan Mountains are located in the central part of China,stretching from southern part of the Ningxia Hui Autonomous Region to the northern part of Baoji City,Shaanxi Province and covering the southwestern part of the Ningxia Hui Autonomous Region and the eastern part of Gansu Province,this is a small green mountain chain about 200 kilometers long with a general elevation over 2,000 metres.Its special natural environment and faunal component makes it an important component of the zoographic regionalization in China.Tardigrada fauna and species diversity of these areas has never been studied.Tardigrada fauna and species diversity of the Liupanshan Mountains was studied in this paper.In consideration of coverage area and environmental representativeness,a total of seven sampling sites were designed,including Guanshan,Wushan,Zhiwuyuan,Xiaonanchuan,Dawanxiang,Liangdianxia and Wenquancun.Six hundred moss samples were collected.Tardigrades were extracted from moss and identified and the individual number were counted.Furthermore,the tardigrade fauna,species diversity and community similarity among sampling sites were analysed.The results are listed as below.1.Three thousand tardigrades were collected.They belonging to two classes(Heterotardigrada,Eutardigrada),three orders(Echiniscoidea,Apochela and Parachela),seven families(Echiniscidae,Milnesiidae,Hypsibiidae,Ramazzottiidae,Isohypsibiidae,Macrobiotidae and Richtersiidae),16 genera(Bryochoerus,Bryodelphax,Cornechiniscus,Echiniscus,Pseudechiniscus,Milnesium,Diphascon,Hypsibius,Pilatobius,Ramazzottius,Doryphoribius,Isohypsibius,Macrobiotus,Mesobiotus,Paramacrobiotus and Richtersius)and 36 species.30 species are new record to the Liupanshan Mountains,three species are new record to China,and three species are new to science.2.The species diversity index Shannon-Wiener index of all sampling sites are listed from large to small as below:Wenquancun>Wushan>Dawanxiang>Guanshan>Zhiwuyuan>Liangdianxia>Xiaonanchuan;Simpson dominance index from large to small as below:Wushan>Wenquancun>Dawanxiang>Zhiwuyuan>Guanshan>Xiaonanchuan>Liangdianxia;Margalef's richness index from large to small as below:Guanshan>Dawanxiang>Liangdianxia>Zhiwuyuan>Wushan>Xiaonanchuan>Wenquancun;Pielou's evenness index from large to small as below:Wenquancun>Zhiwuyuan>Wushan>Xiaonanchuan>Dawanxiang>Liangdianxia>Guanshan.Number of species of tardigrades are 22 at Guanshan,22 at Zhiwuyuan,20 at Wenquancun,17 at Wushan,17 at Dawanxiang,13 at Liangdianxia,10 at Xiaonanchuan;Number of individuals collected at different sampling sties is listed as below:Guanshan(1,030)>Wushan(582)>Zhiwuyuan(435)>Xiaonanchuan(350)>Dawanxiang(296)>Liangdianxia(172)>Wenquancun(152).3.Community similarity coefficient are medium-level dissimilar and medium-level similar among most sampling sites,of different regions of Liupanshan Mountains most of them are very dissimilar.Community similarity coefficient between Dawanxiang and Liangdianxia was the highest,while,community similarity coefficient between Wushan and Xiaonanchuan was the lowest.4.Of all species,Pseudechiniscus chengi and Macrobiotus sp.5 were dominant species,1,352 Pseudechiniscus chengi and 475 Macrobiotus sp.5 were obtained,number of individual separately accounts for 44.81%and 15.74%;Ten species are common ones:Bryodelphax asiaticus,Echiniscus blumi blumi,Hypsibius dujardini,Isohypsibius glazovi,Isohypsibius lunulatus,Isohypsibius prosostomus,Mesobiotus sp.,Paramacrobiotus richtersi,Ramazzottius oberhaeuseri and Milnesium tardigradum tardigradum,number of them respectively is 34,134,186,33,50,37,147,51,120 and 126;The rare class group including 24 species.5.The Liupanshan Mountains and Yunnan-Guizhou Plateau shared eight genera and 12 species;the Liupanshan Mountains and Micang Mountains shared six genera and ten species;the Liupanshan Mountains and Tsinling Mountains and Wuyi Mountains shared six genera and nine species.