Research Of Reproductive Behavior And The Habitat Selection Of Breeding Period Hynobius Maoershanensis

Hynobius maoershanensis,belonging to Amphibia,Caudata,Hynobiidae,Hynobius,was published in 2006.The species,endemic in China,is currently known to distribute only in a narrow area of Maoershan Natural Reserve,Xingan,Guangxi Zhuang Autonomous Region.Hynobius maoershanensis mainly distributed in the altitude of 2000m and the extremly narrow area less than 3000m.And all individuals only appeared in 5 locations.Because of the developing eco-tourismin Maoershan,its habitat area reduce and habitat quality declining continuously,spawning sites of Hynobius maoershanensisare highly disturbed by human.According to published research and our project team's preliminary work,we took Hill-top lake,Sanjiang source,Yeren lake in Guangxi Maoershan Nature Reserve as the research sites.Through the investigation,1401 pairs of Hynobius maoershanensis egg bags were found.According to the comparison of the preliminary observation between 2015 and 2016,and the habit that male guard off springs druing the period from eggs to tapoles,it is estimated that the percentage of female participation in spawning is 5:1,about 300 males and 1400 females involved in mating,and thus more than 1700 in total.There exist sexual size dimorphism phonemon in Hynobius maoershanensis,which male is greater than the female in body length,head length,and tail length.Hynobius maoershanensis larvae in the high density conditions tend to eat each other,and may cause some variation of larval shape,head and mouth will become larger.To study of Hynobius maoershanensis habitat selection in reproductive season,we select temperature and humidity,vegetation type,vegetation coverage,water area,water depth,water type,bottom sand ratio,human disturbance and other 20 kinds of habitat factor to investigate.Associated with the actual situation of Maoershan Reserve.randomly set up 61 plots to survey,with egg bags for selected plots,while no egg bags as control plots,and finally analyse the survey results:(1)Analyze vegetation type,water type,shore conditions,egg bags suspended substances,coveringson the water and human disturbance degree of 6 kinds of descriptive type ecological factors with chisquare test,and the differences between select edplots and control plots.The results show that the choice of selected plots or control plots are significant in 3 factors of shore conditions,coverings on the water,and water type;while there is no significant difference in three kinds of ecological factors,vegetation type,human disturbance degree,egg bags suspended substances.(2)Kolmogorov-Smirnov Test on 14 kinds of numerical ecological factors indicate that 5 factors of air temperature,humidity,water temperature,pH and depth are normal distribution,9 factors of vegetation coverage,vegetation height,water area,water velocity and bottom sand ratio are abnormal distribution.(3)Conduct T-test for 5 factors of normal distribution,Mann-Whitey U Test for 9 factors of abnormal distribution,and compare the difference between selected plots and control plots.The results show that the vegetation coverage,sand ratio,water velocity and water area have significant difference in the choice of selected plots and control plots,indicating Hynobius maoershanensis tend to choose waters of low vegetation coverage,low bottom sand ratio,low water velocity and large water area to spawn.(4)Stepwise discriminant of 14 numeric ecological factors,characteristic value is 0.748,100 percentage of variance,the total variance ratio is 100%and the canonical correlation coefficient is 0.654,only a discriminant function:egg bags =0.965 X vegetation coverage +0.614 X bottom sand ratio +0.000.It can be seen that,in the breeding season,the vegetation cover and bottom sand ratio of two ecological factors can distinguish selected plots and control plots,correct classification rate is 80.3%.Vegetation coverage and bottom sand ration contribute largest in the test,respectively 0.840 and 0.622.(5)Stepwise regression analysis for the Hynobius maoershanensis egg bags and 14 kinds of logarithmic numeric ecological factor,stepwise regression equation:egg bags =160.254 ×surface humidity-vegetation coverage X 29.527-124.304.The regression equation predicts that in Hynobius maoershanensis breeding habitat selectionsignificantly correlated with surface humidity,negatively correlated with vegetation coverage,the F statistic is 13.374,significant level of automatic inspection system for 0.000,significantly related.The results show that the number of spawning Hynobius maoershanensis has a great relationship with the surface humidity and vegetation coverage of the spawning ground surface,that is,high humidity and low vegetation coverage with more eggs.The comprehensive results show that Hynobius maoershanensis microhabitat preference is:low water velocity,low vegetation coverage,more covings on the water cover,low bottom sand ratio,complex shore conditions,large hydrostaticwater area;these ecological factors are the main factors in Hynobius maoershanensis breeding habitat selection.Stepwise discriminant analysis results show that the vegetation cover and bottom sand ratio of two ecological factors can be resolved in Hynobius maoershanensis breeding selection plots and control plots,correct classification rate is 80.3%.So,we could propose suggests on how to protect Hynobius maoershanensis.