闽西山区养殖棘胸蛙两性异形

Sexual dimorphism of the frog,Paa spinosa in mountainous areas of the western Fujian

通过测量和比较采自福建闽西山区棘胸蛙(雌雄各82只)的体质量、头体长、吻长、头长、头宽、前足长、前肢长、后足长、后肢长、眼间距、鼻间距、肩宽、肩肛距和眼径等14个两性形态学指标,研究养殖群体棘胸蛙的两性异形。结果表明,除吻长、眼间距和眼径外,其余11项测量值均呈现出雄性显著大于雌性(P<0.05),雌性与雄性的平均头体长比值为1.073,异形指数为0.068。在控制体质量的基础上得出,雄性头体长、吻长和眼径与体质量间存在显著相关(P<0.05);雌性头体长、前肢长和肩宽与体质量间存在显著相关(P<0.05)。经多元回归分析,分别建立了表型性状对体质量的多元回归方程:雄性体质量=3.620×头体长+0.626×后肢长-5.847×眼径+0.728×吻长-269.868;雌性体质量=2.914×头体长+1.502×前肢长+1.521×肩宽-304.518。闽西山区棘胸蛙两性异形可能是在性选择压力和生育力压力共同作用下,物种自然选择和系统演化的结果。

The present study compared the differences of 14 morphological traits,including body weight(BW),snout-urostyle length(SUL),snout length(SL),head length(HL),shoulder-to-anal length(SAL),froe foot length(FFL),fore limb length(FLL),hind foot length(HFL),hind limb length(HLL),interorbital space(IS),internasal distance(INS),head width(HW),shoulder width(SW)and eye diameter(ED)between the females and the males of Paa spinosa in mountainous areas of the western Fujian.The results showed that except snout length,interorbital space and eye diameter,the other 11 measurements values were significantly larger in males than in females(P<0.05).The index of sexual dimorphism reached 0.068 and males Paa spinosa frogs were on average 7.3%longer in body length than that of the females.There was a significant correlation between snout-urostyle length,snout length,eye diameter and body weight in males(P<0.05).There was a significant correlation between snout-urostyle length,fore limb length and shoulder width and body weight in females(P<0.05).Multiple regression equations were used to estimate body weight and body traits.The equation for BW of the males was BW(♂)=3.620×SUL+0.626×HLL-5.847×ED+0.728×SL-269.868.Similarly,the equation for females was BW(♀)=2.914×SUL+1.502×FLL+1.521×SW-304.518.The sexual dimorphism of P.spinosa might be the result of natural selection and systematic evolution under the combined action of sexual selection on males and breeding pressure on females.