Study On Population Ecology Of Feirana Kangxianensis

Feirana kangxianensis is an endemic amphibian species,which belonged to Feriana,Dicroglossidae,Salientia,which only distributed in Longnan mountainous area of Gansu province of China.Because its location is not only the north and south climate demarcation zone,but also one of the interpenetrating channels of the eastern and Palaearctic species of the animal geography and amphibians are known as the indicators for their rapid response to the environment changes.Thus in this paper,studies on the population ecology of F.kangxianensis were carried based on the field work in Douba countryside.The purpose of this study is to provide basic information for the protection of endemic amphibians in China,and for the follow-up study of amphibious species in China.On the basis of field work,biological characteristics of adult and larval and the selection of over wintering of F.kangxianensis was investigated by using line transect method,direct counting method and other methods of investigation,and both the changes in the number of population and population density were calculated and analyzed from 2014 to 2017,according to the monitoring results of the special item of biodiversity of amphibious animal in Kangxian County,161 samples(female: 73;male: 68;larvae: 20)of F.kangxianensis were collected to reveal the age groups,fatness and gender specific through the measurement of the morphological index.Firstly,biology characteristics of F.kangxianensis was analyzed and found that the common labial tooth row formula of was ?: 5+5 / 1+1:?.Based on principal component analysis of winter habitat selection,it is considered that the key factors for overwintering of this species are water temperature,distance roads,vegetation coverage and forest edge distance.Secondly,based on the survey data,analysis of the number and density of population indicated that June was the anal peak of population fluctuations for F.kangxianensis.The order of average density was 38.67ind/hm2> 33.03 ind/hm2> 31.00 ind/hm2> 29.20 ind/hm2.The environmental pollution caused by human agricultural activities and the construction of roads are one of the reasons for the small number of F.kangxianensis.Secondly,division of age group and the structure of the F.kangxianensis population were analyzed,and deeply discusses the composition of the age structureof the F.kangxianensis based on the data of morphological characteristics.And the sex ratio,fatness(K)and the ratio of weight to body length(Kwl)of age group were investigated.Results showed that there were significant positive relation between the length of the body and the weight.The population was divided into 5 age groups according to the cluster analysis of SVL/W and T-test.The sex ratio was 1.07:1.The age structure conical map shows that the population is a increasing population.The Kwl was the least in April and the most occurred in June,it indicated that,in April,at the end of the winter,the state of hibernation was gradually revived,and the nutrients stored in it have been basically consumed,so that more food will be consumed to supplement the physical energy.Finally,the sexual dimorphism of F.kangxianensis was analysised based on SPSS23.0.Results showed that SVL of female was higher than that of male.The growth rate of four morphological characteristics of female,such as HL,would gradually outweigh the male,when individuals grew to a certain stage,while the growth rate of EL and TYD of male would faster than that of female,when an individuals grew to a certain stage.Growth rate of 3 morphological features,including SL,were similar.The hypothesis of the fecundity selection could explain the sexual dimorphism of F.kangxianensis properly.The reason for the difference between male and female may be the female of larger body could increase spawning rate and survival rate,and male of smaller body would contribute to reduce reproductive weight and mortality rate of female.