【作者】 何南；

【导师】 武正军；

【作者基本信息】 广西师范大学 ， 生态学， 2011， 硕士

【摘要】 动物的形态特征与其环境适应能力的关系是进化生物学研究的主要内容之一,动物咬力大小被证明与竞争(食物资源竞争、配偶竞争、领域竞争)以及反捕食行为紧密相关。国外关于蜥蜴的咬力报道较多,但是国内尚没见报道。鳄蜥(Shinisaurus crocodilurus)属鳄蜥科(Shiniasuridae)鳄蜥属(Shinisaurus),为单型科单型属,是国家一级保护动物,在进化生物学以及系统分类学上具有重要的研究价值。本文通过研究鳄蜥咬力大小与性二型关系及咬力在最大活动范围竞争中的作用,探讨鳄蜥两性异形的形成原因和咬力的作用机理,为进一步研究鳄蜥的繁殖输出、繁殖成效、领域行为与生物力学等方面提供依据。研究结果如下：1鳄蜥的两性异形通过比较鳄蜥的体型与头部大小等特征的差异,研究了鳄蜥的两性异形情况。结果表明：性成熟鳄蜥个体存在明显的体色差异,成年雄性头胸部腹面呈鲜红色或浅蓝色,而雌性为浅黄色或淡红色；成年雄性头部显著大于成年雌性(头长(HL),P<0.01；头宽(HW),P<0.01),成年雌性腹部长(AL)显著大于成年雄性(P=0.018)；而成年雄性和成年雌性的体长(SVL)以及尾长(TL)差异不显著(SVL,P=0.193；TL,P=0.22)；亚成体头长随体长的增长速率显著大于成年雌性(P=0.021),而亚成体头宽与成年雌性头宽差异不显著P=0.545)；亚成体头部与成年雄性头部呈同速增长(HL,P=0.252；HW,P=0.441)。特定SVL时,亚成体头宽显著大于成年雌性头宽(P<0.01)；亚成体头长显著大于成年雄性头长(P<0.01),但亚成体头宽与成年雄性头宽差异不显著(P>0.05)。研究结果表明鳄蜥存在局部两性异型。2鳄蜥的咬力大小及其影响因素不同性别年龄组的鳄蜥的咬力差异极显著(F2,88=161.303,P<0.01),雄性成体的咬力(14.74±0.16N)极显著大于雌性成体(13.55±0.26N)(P=0.003),雄性成体和雌性成体的咬力均显著高于亚成体(9.17±0.25N)(所有P<0.01)。逐步回归结果显示：下颚长度是影响咬力大小的主要因子(R=0.547,P<0.01),头长为次要因子(R=0.299,P=0.002)。以下颚长的回归剩余值为协变量进行协方差分析,结果显示雄性的咬力显著大于雌性(ANCOVA:BF—F1,54=9.896,P=0.003)。单独比较头部形态与咬力大小的关系时,以头部与体长SVL的回归剩余值为协变量,咬力原始值为白变量,协方差分析发现,雌雄两性鳄蜥的头长(斜率：F1,54=0.084,P=0.773,截距：F1,54=5.530,P=0.023),头高(斜率：F1,54=0.504,P=0.480,截距：F1,54=10.304,P=0.002),头宽(斜率：F1,54=0.014,P=0.908,截距：F154=10.109,P=0.002)越大,咬力就越大,且雄性大于雌性。研究结果表明,雄性成年鳄蜥的咬力大于雌性成年鳄蜥的咬力,下颚长与头长是影响咬力大小的两个主要因素。3饲养条件下鳄蜥活动面积及其与咬力的关系我们于2010年6月至8月,对广东省罗坑自然保护区饲养条件下鳄蜥的日活动面积与最大活动范围进行观察,同时测量实验个体的咬力大小,研究饲养条件下鳄蜥活动面积与咬力的关系。研究结果为：①同一鳄蜥的日活动面积存在显著差异(P<0.05),单因素方差分析多重比较(Multiple measures ANOVA)显示,六个饲养池内的雄性成体鳄蜥之间的日平均活动面积差异不显著(F5,235=1.777,P=0.118),雌性成体之间的日平均活动面也不存在差异(F5,233=1.827,P=0.108)。②把所有池子内的鳄蜥按年龄与性别分组进行比较,不同性别年龄组之间的日均活动面积存在极显著差异(F2,47=12.670,P<0.01),其中雄性日均活动面积(2.56±0.13m2)显著大于雌性(2.03±0.12 m2)(P=0.031),亚成体(3.14±0.21 m2)极显著大于雌性(P<0.01),亚成体大于雄性(P=0.028)。不同性别年龄组之间的最大活动范围也存在极显著差异(F2,47=5.807,P=0.006),其中雄性(8.77±0.22 m2)显著大于雌性(7.54±0.40m2)(P=0.034),亚成体(9.22±0.46m2)极显著大于雌性(P=0.008),亚成体与雄性差异不显著(P=0.686)。③同一池子内的鳄蜥之间的最大活动范围存在很大的重叠现象；④回归分析雄性成体最大活动范围影响因子显示只有咬力(x)与最大活动范围(y)呈显著正相关关系(P=0.028,R=0.516,回归方程为y=0.5898x+0.0958)⑤鳄蜥的最大活动范围(y)与日平均活动面积(x)呈正相关关系,其回归方程为：Y=0.816X+6.5526,(R2=0.1364,P<0.05)。更多还原

【Abstract】 Studying the relationship between morphological characteristics and environment adaption of animals has been one of contains of evolution biology. Bite force capacities may be tightly linked to both the type and magnitude of the ecological challenges of food acquisition, mate acquisition, territory acquisition and antipredation in vertebrates. Bite forece of lizards had been reported widely in abroad, but no study was found in China. Shinisaurus crocodilurus is a National Class I protected animal in China, and has important scientific value in evolutionary and systematic biology. In this paper, we studied the relationship between bite force and sexual dimorphism in Shinisaurus crocodilurus, and studied the function of bite force in the maximun ranges of activity competition for understanding the cause of the sexual dimorphism and effect mechanism of bite force. This study is the basis for further studies on reproductive output, reproductive value, territory behavior and biomechanics of Shinisaurus crocodilurus1. Sexual dimorphism of Shinisaurus crocodilurusWe studied the sexual dimorphism of Shinisaurus crocodilurus through comparing body size and head size among female, male and juveniles. The results show that the ventral color of head and breast between male and female is different, it is vivid red or light blue for male and light yellow or light red for female. The head size (including head width (HW) and head length (HL)) of male is significantly larger than that of female (HL, P<0.01; HW, P<0.01), and abdomen length (AL) of female is significantly longer than that of male (P=0.018). However, the snout-vent length (SVL) and tail length (TL) between male and female are not significantly different (for SVL, P=0.193; for TL, P=0.22). The increasing rate of head length with SVL for juveniles was higher than that for females (P=0.021), whereas the head width was not significantly different between juveniles and females (P=0.545). Both the head size (including head length and head width) of juveniles and males increased with SVL at the same rate (for HL, P=0.252, for HW, P=0.441). When SVL was kept constant, head width of juveniles was larger than that of females (P<0.01) and head length of juveniles was larger than that of males (P<0.01), but the head width between juveniles and males was not significantly different (P>0.05). The results indicated that partial sexual dimorphism existed in Shinisaurus crocodilurus.2. Bite force and its influencing factors in Shinisaurus crocodilurusSignificant differences in bite force were observed among different sex and age groups (F2.88=161.303, P<0.01), the bite force of adult males (14.74±0.16N) was significantly higher than that of adult females (13.55±0.26N) (P=0.003), Both of male and females were significantly higher than that of juveniles (9.17±0.25N) (both P<0.01).A multiple regression analysis (stepwise) showed that lower jaw length was the first effect factor for bite force in the significant mode(R=0.547, P<0.01), and the head length was the second effect factor(R=0.299, P=0.002). Analyses of covariance with residual lower jaw length as the covariate demonstrated that adult males had significantly larger bite force than adult females (ANCOVA:BF—F1,54=9.896,P=0.003). When the relationships of only head shape (head length,head width, head heigth) and bite force in adult Shinisaurus crocodilurus were analyzed, results of analyses of covariance with residual head shape and snout-vent length as the covariate showed that increase with the head length (slopes:F1,54=0.084, P=0.773, intercept:F1,54=5.530, P=0.023), head width (slopes:F1,54=0.014,P=0.908, intercept:F1,54=10.109,P=0.002) and head heigth (slopes:F1,54=0.504,P=0.480, intercept:F1,54=10.304, P=0.002) the bite force increased at the same time, and the bite force of adult male was larger than that of adult females. In a word, the bite force of adult male is larger than that of adult female in Shinisaurus crocodiluru, and the lower jaw length and the head length were highly correlated with bite force.3. The relationship between activity area and bite force in Shinisaurus crocodilurusDuring June and Auguest,2010, we recorded the maximum range of activities and daily activity area, and tested the bite force of Shinisaurus crocodilurus which were reared in six captive pools in Luokeng Nature Reserve in Guangdong Province, and we studied the relationship between the home ranges and bite force. The results showed:①There was significant difference in daily activity area of the same individual (P<0.05); ANOVA multiple comparison showed that both daily activity areas of adult male and female among six pools were not different (for male F5,235=1.777,P=0.118; for female F5,233=1.827,P=0.108).②The results of One-way ANOVA showed that the daily activity areas among juveniles(3.14±0.21 m2), adult males(2.56±0.13m2) and adult females(2.03±0.12 m2)were significant different F2,47=12.670, P<0.001), and that of adult males was larger than that of adult females (P=0.031), and that of juveniles was larger than that of adult females (P<0.01) and adult males (P=0.028). The maximum range of activity areas of different age and sex groups were also significant different (F2,47=5.807, P=0.006), and that of adult males (8.77±0.22 m2) was larger than that of adult females (7.54±0.40m2) (P=0.034), that of juveniles(9.22±0.46m2) was larger than that of adult females (P=0.008), but the maximum range of activity between adult males and juveniles were not differece (P=0.686).③There were a large home range overlap in the same pool.④Regression analysis showed that only bite force (x) was positive correlative with the range of activity(y) (P=0.028,R=0.516, the Regression equation was:y=0.5898x+0.0958). The maximum range of activities (y) and the daily activity area (x) correlated significantly, the Regression equation was:Y= 0.816X+6.5526.(R2=0.1364, P<0.05)更多还原