鲶鱼和胡子鲶的两性异形与雌性个体生育力

Abstract

PDF HTML阅读 XML下载 导出引用 引用提醒 鲶鱼和胡子鲶的两性异形与雌性个体生育力 DOI: 10.5846/stxb201306021274 作者: 作者单位: 丽水学院,丽水学院生态学院,丽水学院生态学院,丽水学院生态学院 作者简介: 通讯作者: 中图分类号: 基金项目: 国家自然科学基金癣项目（31270443，30970435）；丽水市科技计划资助项目（20110426）；浙江省大学生科技创新活动计划资助项目（2011R429008） Sexual size dimorphism and female individual fecundity of Silurus asotus and Clarias fuscus Author: Affiliation: College of Ecology,Lishui University,College of Ecology,Lishui University,College of Ecology,Lishui University,College of Ecology,Lishui University Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:检测了鲶鱼（Silurus asotus）和胡子鲶（Clarias fuscus）繁殖期18个形态特征的两性异形以及雌性个体生育力。结果表明，鲶鱼和胡子鲶雌雄性别比例均符合1：1。One-way ANOVA显示，鲶鱼雌雄个体体长差异不显著，胡子鲶雌性个体体长显著小于雄性个体（P < 0.05）。以体长为协变量的One-way ANCOVA显示，特定体长的鲶鱼雌性个体的眼间距和体高显著大于雄性个体（P < 0.05），两性间其它局部特征不存在显著的两性差异；特定体长的胡子鲶雌性个体的体高、腹鳍基前距和腹鳍臀鳍间距显著大于雄性个体，雌性个体的臀鳍基长、尾柄高和尾鳍长显著小于雄性个体（P < 0.05），两性间其它局部特征不存在显著的两性差异。Two-way ANOVA显示，胡子鲶体长显著大于鲶鱼（P < 0.05），性别及物种与性别两因素的相互作用对体长影响不显著。以体长为协变量的Two-way ANCOVA显示，胡子鲶的头长、头宽、吻长、眼间距、尾柄高、尾鳍长、背鳍基前距、背鳍基长、腹鳍基前距、腹鳍臀鳍间距、体重和去内脏体重显著大于鲶鱼，头高、体高、臀鳍基长显著小于鲶鱼（P < 0.05），物种间的其他形态特征变量差异不显著；雌性个体的体高、背鳍基前距、腹鳍基前距、腹鳍臀鳍间距显著大于雄性个体，臀鳍基长、尾柄高、尾鳍长、背鳍基长显著小于雄性个体（P < 0.05），两性间的其他形态特征变量差异不显著；物种与性别两因素的相互作用对体高、臀鳍基长、尾柄高、尾鳍长、背鳍基长和腹鳍臀鳍间距影响显著，对其余的形态特征变量影响不显著。15个形态特征变量的主成分分析（Eigenvalue ≥ 1）发现，前2个主成分共解释68.4%的变异。头宽、眼间距、尾柄高、尾鳍长、背鳍基前距、背鳍基长、腹鳍基前距和腹鳍臀鳍间距在第一主成分有较高的正负载系数，臀鳍基长在第一主成分有较高的负负载系数（解释51.2%变异）；眼后头长在第二主成分有较高的负负载系数（解释17.2%变异）。胡子鲶在第一主成分和第二主成分的分值均显著大于鲶鱼，雌雄两性的差异以及两因素的相互作用对分值的影响均不显著。实验检测的鲶鱼、胡子鲶的怀卵数量与体长和体重回归关系显著。One-way ANCOVA及矫正平均值Tukey's检验显示，特定体长的胡子鲶的产卵数量显著大于鲶鱼。性选择是胡子鲶大个体雄性形成的主要原因，同时影响与运动相关的尾部特征。生育力选择更多的影响与雌性胡子鲶较大腹腔容积相关的形态特征变异。环境因子、食物可得性和营养状况同时影响了个体大小两性异形的形成。 Abstract:We measured the sexual size dimorphism in eighteen morphological traits and female individual fecundity of Silurus asotus and Clarias fuscus collected from Lishui (Zhejiang, eastern China) in reproductive seasons. It had been found that their sex ratios were both 1:1. One-way ANOVA showed the adults of S. asotus were not sexually dimorphic in body length, while body length was significantly larger in adult males than in adult females of C. fuscus (P < 0.05). One-way ANCOVA with body length as a covariate showed that the females of S. asotus with special body length were significantly larger than the males in interorbital width and body depth (P < 0.05), while other examined morphological traits did not differ between the sexes. Furthermore, the females of C. fuscus with special body length were significantly larger than the males in body depth, pelvic fin precoxal length, and length between pelvic fin and anal fin (P < 0.05), whereas their anal fin coxal length, caudal peduncle depth and caudal fin length were significantly shorter in females than in males, and there were no significant differences between the sexes in any other of the examined morphological traits. Two-way ANOVA showed that body length of C. fuscus was significantly larger than one of S. asotus (P < 0.05), both sex and the interaction of sex and species had no effects on the body length. Two-way ANCOVA with body length as a covariate showed that head length, head width, snout length, interorbital width, caudal peduncle depth, caudal fin length, dorsal fin precoxal length, dorsal fin coxal length, length between pelvic fin and anal fin, body mass and carcass mass of C. fuscus were significantly larger than them of S. asotus, while head depth, body depth and anal fin length of C. fuscus were significantly shorter than ones of S. asotus (P < 0.05). Meanwhile, there were no significant differences in other morphological traits between them. Body depth, dorsal fin precoxal length, pelvic fin precoxal length, length between pelvic fin and anal fin were significantly larger among females than among males, while anal fin coxal length, caudal peduncle depth, caudal fin length and dorsal fin coxal length were significantly shorter among females than among males (P < 0.05). There were no significant differences in other morphological traits between the sexes. The interaction of species and sex had significant effects on body depth, anal fin coxal length, caudal peduncle depth, caudal fin length, dorsal fin coxal, length between pelvic fin and anal fin, but it had no effect on the other morphological traits. A principal component analysis resolved two components (with eigenvalues≥1) from fifteen size-free morphological variables, accounting for 68.4% of variation in the original data. The first component (51.2% variance explained) had high positive loading for size-free values of head width, interorbital width, caudal peduncle depth, caudal fin length, dorsal fin precoxal length, dorsal fin coxal length, dorsal fin coxal length, pelvic fin precoxal length, pelvic fin precoxal length, length between pelvic fin and anal fin, wherea the first component had high negative loading for size-free values of anal fin coxal length. The second component (17.2% variance explained) had high negative loading for size-free values of postorbital head length. C. fuscus had higher scores on the first and the second axes of a principal component analysis than did S. asotu, but both sex and the interaction of sex and species had no critical effect on the scores. The individual fecundity was significantly correlated with the body length and body mass in C. fuscus and S. asotus positively. One-way ANCOVA and Tukey's test showed that C. fuscus with special body length laid significantly more eggs than S. asotus. Sexual selection was the major evolutionary reasons for large males of C. fuscus, simultaneously had effects on tail traits correlated with locomotion. Fecundity selection affected the variations of morphological traits associated with abdominal cavity volume to a large extent. Environmental factors, food availability and nutritional status affected the evolution of sexual size dimorphism at the same time. 参考文献 相似文献 引证文献