The Life History Characteristics And The Spatial Pattern Of The Population Structure Of The Black Snake

The Chinese ratsnake(Zaocys dhumnades)is widely distributed in China,including Taiwan,northwards to Henan,Shanxi and Gansu.The snake has been overexploited by local people for food and traditional Chinese medicine.However,we have not been collected enough ecological information about this snake,such as,the reproductive characteristics among populations;trade-offs between size and number of eggs,and genetic structure.The results of this study are as follows:We collected the Chinese ratsnake(Z.dhumnades)from five geographically separated populations in JiuJiang(JJ),JiangShan(JS),QuanZhou(QZ),ZaoYang(ZY)and TianTai(TT)of China to study geographic variation in female reproductive traits.Not all reproductive traits varied among the five populations.Of the traits examined,egg-laying date,clutch size,egg mass and egg width differed among the five populations.Egg-laying date,overall stretching from late June to early August,varied among populations in a geographically continuous trend,with females at the most northern latitude(ZY)laying eggs latest,and females at the most southern sites(JJ and QZ)laying eggs earliest.The egg size-number trade-off was evident in each of the five populations and at a given level of relative fecundity,egg mass was more round.We collected the Chinese ratsnake(Z.dhumnades)from four geographically separated populations in JiangShan(JS),QuanZhou(QZ),DeQing(DQ)and TianTai(TT)of China in total 48 females to laboratory.And we kept them in the cage which has comfortable temperature.After the females give birth to eggs,we must collect them in time.We set 24,27 and 30 ? three temperature phrase.We should put the same clutch eggs in different temperature.The result shows that there are no difference among the four populations about heart rate and embryonic stage,but the incubation temperature and the incubation period are negative correction.In the same temperature,the population from southern sites(QZ and JS)with shotter incubation period than nourthem sites(DQ and TT).Microsatellite loci and mitochondrial cytb gene were used to study genetic diversity,gene flow,population structure of Z.dhumnades and snakes were collected from five sample sites in China.We characterized 9 polymorphic microsatellite loci isolated from Z.dhumnades genomic libraries.These markers revealed a relatively high degree of genetic diversity(6-29 alleles per locus)and heterozygosity(Ho ranged from 0.360-0.847 and HE ranged from 0.634-0.941).Our phylogenetic analysis revealed two mitochondrial lineages:Clade A and Clade B.Clade A contained individuals from the southern part of JS and QZ,others belonged to Clade B.Gene flow analysis revealed that the effective number of migrants per population.This phenomenon is that the micro sate lite can reveal the recent events of population,but the mitochondrial gene revealed the earlier historical events.