棒花鱼形态特征的两性异形和雌性个体生育力

测定了棒花鱼(Abbottina rivularis)繁殖期形态特征包括体长、头长、头宽、头高、眼间距、鼻间距、背鳍基长、胸鳍长、胸鳍腹鳍间距、尾柄长、尾鳍长和体重的两性异形和雌性个体生育力。结果表明,雄性个体的数量显著多于雌性个体,雄性个体的体长显著大于雌性个体。特定体长的雌性个体的胸鳍腹鳍间距显著大于雄性个体,头长、头宽、头高、眼间距、鼻间距、背鳍基长、胸鳍长、尾柄长和尾鳍长显著小于雄性个体,雌雄两性体重不存在显著差异。棒花鱼的怀卵数量与体长和体重回归关系显著。偏相关分析显示,当控制第三者恒定时,怀卵数量与体长和体重呈正相关但不显著。棒花鱼存在个体大小和其他局部特征显著的两性异形,雌性个体主要通过腹腔容积的增加提高个体生育力。棒花鱼形态特征的两性异形是性选择和生育力选择共同作用的结果。

Sexual Dimorphism in Morphological Traits and Female Individual Fecundity of Abbottina rivularis

We measured the sexual dimorphism in morphological traits,including body length,head length,head width,head height,interorbital width,internasal length,dorsal fin coxal length,pectoral fin length,space between pectoral fin and pelvic fin,caudal peduncle length and caudal fin length,and female individual fecundity in a population of Abbottina rivularis,from Xiaoshan District,Zhejiang Province in reproductive season.It has been found that the number of adult males is larger than that of female and the body length of adult females is significantly shorter than that of adult males.The females with special body length is significantly larger than the males in space between pectoral fin and pelvic fin,while the former are significantly shorter than the latter in head length,head width,head height,interorbital width,internasal length,dorsal fin coxal length,dorsal fin coxal length,pectoral fin length,caudal peduncle length and caudal fin length.There is no significant sexual difference in body weight.The individual fecundity is significantly positively correlated with the body length and body weight in A.rivularis.A partial correlation analysis showed that the individual fecundity is positively correlated with the body length and body weight but not significant when the third invariableness is in control.There are significant sexual dimorphism in body size and local morphological traits. The adult females of A.rivularis increase the individual fecundity through increasing capacity of abdominal cavity.The sexual dimorphism in morphological traits of A.rivularis is the result of sexual selection and fecundity selection.