大蹼铃蟾的两性异形

2018年6—8月,测量采自云南省昆明市金殿水库后山的71只(47♂,24♀)大蹼铃蟾Bombina maxima成体的体长、头长、头宽等15项形态特征指标并检验该物种的两性异形。结果表明:雄性平均体长为53.54 mm±1.14 mm,雌性平均体长为52.74 mm±1.45 mm,雄性与雌性平均体长比为1.015,两性异性指数为0.01;大蹼铃蟾的体长、体质量与性别之间的差异无统计学意义;除了雌性的眼间距外,其余13项形态特征与体长均有极显著相关性;以体长为协变量的协方差分析结果显示,大蹼铃蟾的头长、吻长、前臂宽、腿或后肢全长、胫长、胫宽和跗足长在两性间的差异有高度统计学意义;雄性的这7项形态特征随体长的生长速率大于雌性。性选择假说能解释大蹼铃蟾的两性异形现象。

Sexual Dimorphism of Bombina maxima

From June to August in 2018, sexual dimorphism of Bombina maxima was studied on 71 adults (47♂, 24♀) collected from the back hill of the Golden Temple Reservoir in Kunming, Yunnan province. By measuring the 15 morphological characteristics, such as body length, head length, head width, etc., the results showed that the average body length of male B. maxima was 53.54 mm±1.14 mm, while the female's average body length was 52.74 mm±1.45 mm. The average body length ratio of male to female was 1.015, and the heterosexual index was 0.01. According to independent sample t test results, B. maxima had no statistical significance in body length and body mass between sexes. The results of correlation test showed that all the other 13 morphological characteristics were significantly correlated with body length, except interorbital space in females. Using body length as the covariant, the covariance analysis results showed that, 7 morphological characteristics of B. maxima such as head length, snout length, diameter of lower arm, leg or hind limb length, tibia length, tibia width and length of foot and tarsal were highly statistical significance between sexes. The results of unary linear regression showed that the growth rate of male head length, snout length, diameter of lower arm, leg or hind limb length, tibial width, tibial length and length of foot and tarsal were larger than those of female. In conclusion, the sexual dimorphism of B. maxima can be explained by the sexual selection hypothesis.