瓯江鲫鱼胸鳍的波动性不对称、两性异形和生育

Pectoral Fin Fluctuating Asymmetry, Sexual Dimorphism and Fecundity in the Crucians,Carassius auratus in Oujiang River,Zhejiang

研究浙江瓯江鲫鱼胸鳍的波动性不对称、两性异形和生育力。雌雄两性的鳍长、鳍条数的不对称均属波动性不对称。雌雄两性的胸鳍长和鳍条数的不对称指数之间相关关系不显著。雌性个体显著大于雄性个体,特定体长的雄性胸鳍长显著大于雌性,雄性的鳍条数显著大于雌性。鳍长和鳍条数的不对称指数雌雄两性差异不显著,雌雄两性鳍条数对称个体的比例差异不显著。以体长和时间为控制变量,怀卵数量与鳍长和鳍条数的不对称指数具有显著的负相关,与鳍长和鳍条数的相关不显著。以体长和发育时间为控制变量,平均卵重与鳍条数的不对称指数具有显著的正相关,与其他变量的相关不显著。分析表明,雄性较大的胸鳍可能与雄性的性选择有关,胸鳍的波动性不对称可能提供了一种发育历程的指示,间接影响雌性生育力。

We used crucians （Carassius auratus） collected from Oujiang River （Zhejiang, eastern China） to study pectoral fin asymmetry, sexual dimorphism and fecundity. The asymmetry of pectoral fin length and pectoral fin ray number met the criteria of ideal fluctuating asymmetry in both sexes, There was no significant correlation between the indexes of pectoral fin length and pectoral fin ray number of females and males. The body length of adult females was significantly greater than that of adult males. The pectoral fin length of males with special body length was significantly greater than that of females. The pectoral fin ray number of males was significantly larger than that of females. There was no significant sexual difference in indexes of pectoral fin length and pectoral fin ray number. There was no significant sexual difference in percents of individuals with symmetrical fin ray number. With the body and time as control variables length as control variable, there was significant regression relation between egg number and morphological variables of pectoral fin, including pectoral fin length, pectoral fin ray number, indexes of pectoral fin length and index of pectoral fin ray number, which showed a significant negative correlation between egg number and indexes of pectoral fin length and pectoral fin ray number, but no significant correlation between egg number and variables of pectoral fin length and pectoral fin ray number. With the body length and time as control variables, there was significant regression relation between mean egg mass and morphological variables of pectoral fin, which indicated significant positive correlation between mean egg mass and index of pectoral fin ray number, but no significant correlation between mean egg mass and the other variables of pectoral fin. The larger pectoral fin of males might result from sexual selection with any favor to males. The pectoral fin fluctuating asymmetry might provide an index of developmental history, and indirect influence on the fecundity of females