Moran Amy L, McAlister Justin S
Department of Biological Sciences, 132 Long Hall, Clemson University, Clemson, South Carolina 29634, USA.
Biol Bull. 2009 Jun;216(3):226-42. doi: 10.1086/BBLv216n3p226.
Egg size is one of the most important aspects of the life history of free-spawning marine organisms, and it is correlated with larval developmental mode and many other life-history characters. Egg size is simple to measure and data are available for a wide range of taxa, but we have a limited understanding of how large and small eggs differ in composition; size is not always the best measure of the characters under selection. Large eggs are generally considered to reflect increased maternal investment, but egg size alone can be a poor predictor of energetic content within and among taxa. We review techniques that have been used to measure the energetic content and biochemical makeup of invertebrate eggs and point out the strengths and difficulties associated with each. We also suggest a number of comparative and descriptive approaches to biochemical constituent analysis that would strengthen our understanding of how natural selection shapes oogenic strategies. Finally, we highlight recent empirical research on the intrinsic factors that drive intraspecific variation in egg size. We also highlight the relative paucity of these data in the literature and provide some suggestions for future research directions.
卵的大小是自由产卵海洋生物生活史中最重要的方面之一，它与幼体发育模式及许多其他生活史特征相关。卵的大小易于测量，且有大量分类群的数据，但我们对大小不同的卵在组成上的差异了解有限；大小并不总是衡量选择特征的最佳指标。大卵通常被认为反映了母体投资的增加，但仅卵的大小本身可能并不能很好地预测不同分类群内部和之间的能量含量。我们回顾了用于测量无脊椎动物卵的能量含量和生化组成的技术，并指出了每种技术的优点和困难。我们还提出了一些用于生化成分分析的比较和描述方法，这些方法将加强我们对自然选择如何塑造卵子发生策略的理解。最后，我们强调了最近关于驱动卵大小种内变异的内在因素的实证研究。我们还强调了文献中这些数据相对较少的情况，并为未来的研究方向提供了一些建议。
