Parichy David M, Kaplan Robert H
Department of Biology, Reed College, 97202, Portland, OR, USA.
Oecologia. 1992 Oct;91(4):579-586. doi: 10.1007/BF00650334.
Differences in maternal investment and initial offspring size can have important consequences for offspring growth and development. To examine the effects of initial size variability in the frogBombina orientalis, we reared larvae (N=360) in one of two treatments representing different levels of environmental quality. We used snout-vent length at the feeding stage (stage 25, Gosner 1960) as a measure of maternal investment. In a "low quality" treatment, larvae were reared with two conspecific tadpoles and food was limited, whereas in a "high quality" treatment, larvae were reared individually and were fed ad libitum. Among tadpoles reared in the low quality treatment, individuals that were initially small had smaller body sizes through metamorphosis and longer larval periods than individuals that were initially large. Among tadpoles reared in the high quality treatment, initial size had only a weak influence on later larval size, and did not significantly affect metamorphic size of the duration of the larval period. This interaction between maternal investment and rearing conditions suggests that production of initially small offspring could be advantageous if these offspring develop in relatively benign environments, but disadvantageous if environments are more severe. These findings are discussed in light of previous studies that have demonstrated such interactions in organisms with complex life cycles.
母体投资和子代初始大小的差异会对后代的生长和发育产生重要影响。为了研究东方铃蟾（Bombina orientalis）初始大小变异性的影响，我们将360只幼体分成两组，分别在代表不同环境质量水平的两种处理方式下饲养。我们用摄食阶段（戈斯纳1960年定义的第25阶段）的吻肛长度作为母体投资的衡量指标。在“低质量”处理组中，幼体与两只同种蝌蚪一起饲养，食物有限；而在“高质量”处理组中，幼体单独饲养，并随意喂食。在低质量处理组饲养的蝌蚪中，初始较小的个体在变态后的体型比初始较大的个体小，且幼体期更长。在高质量处理组饲养的蝌蚪中，初始大小对后期幼体大小的影响较弱，且对幼体期持续时间的变态大小没有显著影响。母体投资和饲养条件之间的这种相互作用表明，如果这些后代在相对良性的环境中发育，产生初始较小的后代可能是有利的，但如果环境更恶劣则是不利的。我们根据之前在具有复杂生命周期的生物体中证明了这种相互作用的研究来讨论这些发现。
