The Study On Sexual Dimorphism,Dietary,Population Age Structure And Sex Ratio Of Scincella Tsinlingensis

The study of animal life history is a very important part of ecology.It helps people understand the status and role of this animal in ecosystem and the status quo of this species.This paper studies the sexual dimorphism,dietary,population age structure,sexual and female reproduction of Scincella tsinlingensis in five regions of Huozhou in Shanxi,Zhouzhi in Shaanxi,Ningshan in Shaanxi,Min County in Gansu and Ning County in Gansu.Above five regions,S.tsinlingensis was randomly captured,8 morphological characteristics of sexually mature individuals were measured and compared,the gender was identified.SPSS 23.0 was used to understand the differences in 8 morphological characteristics between males and females.All individuals' stomach foods were identified,recorded and organized using anatomical methods to understand the feeding habits.SPSS23.0 was used to make a histogram of frequency distribution of body length of S.tsinlingensis,and its population age structure was obtained.The number of males and females in different regions and different age groups was counted,and sex ratio of S.tsinlingenis was obtained.Linear regression was used to analyze the relationship between clutch size,clutch weight,egg weight and female size,and female reproduction was researched.The main results of this study are as follows:(1)Sexual dimorphism: The differences in average snout-vent length between males and females are statistically significant,showing that females were larger than males.The influence of snout-vent length is removed,the differences of tail length,head length,head width,head height,abdomen length,fore limb length and hind limb length between males and females are statistically significant.Among all morphological features,females are significantly larger than males in terms of abdomen length,while males are significantly larger than females in other six morphological indexes.The differences in snout-vent length between males and females are related to reproductive stress.The differences in head between males and females are caused by reproductive pressure and sexual selection,while the differences in abdomen are mainly caused by reproductive pressure,and the sexual dimorphism of tail and appendage are mainly caused by sexual selection.Therefore,sexual selection and reproductive stress are the most fundamental causes of sexual dimorphism.(2)Dietary study: The food of S.tsinlingensis is mainly composed of animal foods,no vegetable food has been identified.The food include 8 orders 22 families,arachnid,crustacean rat,oligochaete and gastropod snail.There are some differences in the food composition of different geographical populations,the food habits of S.tsinlingensis in Min County and Ning County,Ning County and Huozhou areas are significant,and the food habits in other areas are not significant.There are some differences in the food composition of different genders.The food habits of males and females in all samples and Min County area are significant,and the dietary differences of the males and females in other places are not significant.There are some differences in food composition in different age groups in Huozhou,but the differences are not significant.Their food types are 6 orders and 8 families.Geographical differences in food composition may be related to differences in food availability in different geographical environments.The gender differences in food may be related to female reproduction,differences in males and females' head width,and the like.The food of larvae is generally smaller ants,etc.The larvae need more energy during growth and development.In addition,due to the limitation of head width,larvae can only prey on smaller foods.(3)Population age structure and sex ratio: Age structure of all individuals can be divided into four groups,with the largest number of individuals at age of 1st,the overall is growth.Age structure of S.tsinlingensis in Huozhou can be divided into three groups,with the largest number of individuals at age of 1st,the overall is growth.Age structure of S.tsinlingensis in Ning County can be divided into three groups,with the largest number of individuals at age of 2st,the overall is stable.Age structure of S.tsinlingensis in Zhouzhi area can be divided into three groups,with the largest number of individuals at age of 1st and 3st,the whole is stable.Age structure of S.tsinlingensis in Min County can be divided into three groups,with the largest number of individuals at age of 1st and 2st,the overall is growth.The number of S.tsinlingensis captured in Ningshan area don't reach statistical standard,so it is not analyzed.Sex ratios of S.tsinlingensis in different regions and age groups are different.Sex ratios in different regions are different,but the number of females is higher than males.Sex ratios in Zhouzhi area is the largest,the ratio of males to females is 6.50,followed by Huozhou,the ratio of males to females is 4.75,and sex ratios in Ning County and Min County are also different,which are 3.29 and 1.66.This phenomenon may be related to factors such as escape individuals,female reproduction and environment.The different age structures of different geographical populations may be related to the time period of capturing S.tsinlingensis and different geographical environment.The differences in sex ratio may be related to factors such as escape individuals,female reproduction and environment.(4)Female reproduction: Clutch size of S.tsinlingensis is 3-8,clutch size and clutch mass are positively correlated with SVL of females.There is no correlation between egg mass and female's SVL.There are no correlation between egg mass and clutch size.S.tsinlingensis increases reproductive output by increasing clutch size and clutch mass.