Benelkadi Hadj Aissa, Roberto C. RodrÃguez-Caro, Mansour Amroun, E. Graciá
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引用次数: 0
摘要
由于表型可塑性和性别偏倚的选择压力,通常通过研究两性二态性来评估陆龟形态的种内变异。然而,根据壳尺寸测量的选择,推断可能会有所不同。在这项工作中,我们确定了线性测量,最好地描述了刺腿龟Testudo graeca whitei的两性二态性。我们在阿尔及利亚大草原中部的Mergueb自然遗址对一个种群的67只个体(24只雄性,43只雌性)进行了34项甲壳和板层测量。在方差分析中,34项测量中有22项显著显示性别尺寸二态性。当用ANCOVAs分析两性形状二态性时,9个测量值显示没有共享异速,并使用测量值作为协变量来校正尺寸。与此同时,在剩下的23项测量中,有17项显示出形状上的显著差异。PCA分析类似地描述了T. graeca的性别二态性。一般来说,雌性往往比雄性大,尤其是在中间的鱼鳞上,这可能与卵的数量有关。另一方面,雄性的前肢和后肢尺寸较大,可能是求爱、雄性争斗和交配的结果。分析结果表明,其中一些测量值特别适合于进一步研究希腊鼠两性二态性的地理变异
The shell measurements that best describe sexual dimorphism in the spur-thighed tortoise Testudo graeca from Algeria
Due to phenotypic plasticity and sex-biased selective pressures, intraspecific variation in tortoise morphology is usually assessed by studying sexual dimorphism. However, inferences may differ based on the choice of shell size measurements for analyses. In this work, we identified linear measurements that best describe sexual dimorphism for the spur-thighed tortoise Testudo graeca whitei. We assessed 34 carapace and plastron measurements in 67 individuals (24 males, 43 females) in a population at the natural Mergueb site located on the central limit of the Algerian steppe. Twenty-two out of 34 measurements significantly showed sexual size dimorphism in ANOVA tests. When analyzing sexual shape dimorphism with ANCOVAs, nine measurements showed no shared allometry with the measurements used as covariates to correct by size. Meanwhile, 17 out of the remaining 23 measurements showed significant differences in shape. PCA analyses similarly described T. graeca’s sexual dimorphism. In general, females tend to be bigger than males, especially in central scutes what is probably linked with clutch sizes commitments. On the other hand, males are larger-sized in anterior and posterior scutes, probably as a result of courtship, male fighting and copulation. Some of the analyzed measurements are revealed as being especially adequate for further studying the geographical variation of sexual dimorphism in Testudo graeca
期刊介绍:
Basic and Applied Herpetology (B&AH) is the open access scientific journal of the Spanish (AHE) and Portuguese (APH) Herpetological Societies. B&AH publishes original Research Papers and updated Reviews about especially interesting issues dealing with any aspect of amphibians and reptiles worldwide. Authors can also submit Short Notes if these are organized around hypotheses appropriately argued and analysed quantitatively.