Xu Xuefeng, Ji Xiang
Department of Biology, School of Life Sciences, Hangzhou Normal College, Hangzhou 310036, China.
Ying Yong Sheng Tai Xue Bao. 2003 Apr;14(4):557-61.
Studies on the ontogenetic shifts in sexual dimorphism in head size (head length and width) and food habits of Eremias brenchleyi were studied. The results showed that adult E. brenchleyi had no obvious sexual dimorphism in body size (SVL). Both sexes differed in head size since hatching, with males having larger heads than females. This sexual dimorphism was much more pronounced between adults than between juveniles (including hatchlings), largely because the increase velocity of head size of males with SVL was faster than that of females. Hatchlings had relatively larger heads to SVL than juveniles and adults, presumably because E. brenchleyi embryos allocated relatively more resources for early survival and growth of hatchlings. Head size of both sexes overall showed an allometric growth pattern with SVL increase ontogeny. Lizards of different sizes and sexes differed, in certain degrees, in food niche breadth and niche overlap. However, no direct evidence showed a noticeable contribution of the divergence in head size to the segregation of food niche between males and females, thereby mitigating the competition between both sexes.
对布氏沙蜥头部大小（头长和头宽）的两性异形以及食性的个体发育转变进行了研究。结果表明，成年布氏沙蜥在体型（吻肛长）上没有明显的两性异形。自孵化以来，两性在头部大小上存在差异，雄性的头部比雌性的大。这种两性异形在成年个体之间比在幼年个体（包括幼体）之间更为明显，这主要是因为雄性头部大小随吻肛长的增长速度比雌性快。幼体相对于吻肛长而言，头部比幼年和成年个体更大，推测是因为布氏沙蜥胚胎为幼体的早期存活和生长分配了相对更多的资源。随着个体发育过程中吻肛长的增加，两性的头部大小总体上呈现出异速生长模式。不同大小和性别的蜥蜴在食物生态位宽度和生态位重叠方面存在一定程度的差异。然而，没有直接证据表明头部大小的差异对雄性和雌性之间食物生态位的分离有显著贡献，从而减轻了两性之间的竞争。
