草原沙蜥幼体的形态两性异形

Sexual Dimorphism in Juvenile Toad-headed Lizard( Phrynocephalus frontalis)

于2011年9月在内蒙古库布齐沙漠捕获118条草原沙蜥(Phrynocephalus frontalis)幼体,测量其部分身体指数并对其两性异形进行研究。结果表明,雄性幼体和雌性幼体的平均体长分别为36.3 mm和34.0 mm,雄性的体长显著大于雌性。两性异形表现为雄性幼体有较大的头部和尾部,雌性幼体具有较大的腋胯距。草原沙蜥幼体的局部形态特征皆与体长成正相关。

A total of 118 juvenile Toad-headed Lizards （Phrynocephalus frontalis） were collected in September 2011 from Kubuqi desert （40° 12＇N, 111 °06 ＇E ） , Inner Mongolia. We measured snout-vent length, head width, tail length and abdomen length to analyze their sexual dimorphism, by t-test and regression analysis. The male was significant larger than the female in snout-vent length （SVL） （ t = 3. 702, df = 116, P 〈 0. 001 ）. The mean SVL of males was 36.3 mm while the mean SYL of females was 34.0 mm. The male had a bigger head （ t =4.616, df=ll6, P =0.002） and longer tail （t =3.958, df= 116, P 〈0.001）, while the female had bigger abdomen （ t = 2. 292, df = 116, P = 0. 024）. All the morphological traits measured were positively related to SVL.