大小等级和大小组合差异对盆养安吉小鲵幼体同种相残率的影响

用改变安吉小鲵 (Hynobiusamjiensis)幼体大小等级、盆养密度和饵料投放量的实验方法 ,研究这些生态要素对同种相残 (撕咬和吞吃 )的影响 ;同时结合Fuetal (2 0 0 3)的研究 ,比较了大小组合的差异对同种相残的影响。结果表明 ,①大小等级、密度与饵料量均显著地影响幼体的被吞吃率 :较小个体易被较大个体攻击 ;低饵料×高密度水平下 ,3个等级大小幼体的同种相残率都最高。②大小组合的差异显著影响幼体间的同种相残率 :不同大小组合的幼体间被吞吃率均显著大于相同大小组合 ,而被撕咬率反之。这证实了体形大小决定种群同种相残率的理论预测。

fects of Size Class and Group Size Structure on Cannibalism in Basin-raising Larval Salamanders,Hynobius amjiensis

To detect the effects of size class,population density and food availability on cannibalism,newborns of larval salamanders (Hynobius amjiensis) were basin-raised in combinations of the ecological factors.Compared with the results of Fu et al (2003),this study evaluated the effect of group size structure on patterns of intra-specific cannibalism.The results showed that:1)Percent of larvae eaten were significantly influenced by size class,density and food availability.Smaller individuals were susceptible to attack by larger individuals.The highest cannibalism of three size-class larvae appeared in the combination of low-density and high-food availability.2)Group size structure significantly affected intra-specific cannibalism.Overall levels of larvae bitten were lower in groups of different-size individuals than in groups of similar-size individuals,but those of larvae eaten were higher in the formers than in the latters.These supported the theoretical prediction that body size determined the cannibalism of a population.