Life History Implications for Free Spawning Invertebrates

在包括海洋无脊椎动物在内的许多分类群中，合子后死亡被认为是繁殖体大小进化的主要选择因子。不幸的是，基于受精卵后死亡率的海洋无脊椎动物卵大小的理论预测很难检验，而且往往与经验数据不一致。本研究将进行一系列的实验室实验，测量卵子大小、精子游泳能力和受精率，并进行一系列的野外实验，以确定这些配子属性在不同环境条件下如何影响受精率。在一项实验中，单个幼虫的DNA指纹将为特定配子属性如何影响受精率和调节精子竞争的结果提供答案。将受精纳入一个全面的生命史理论将解决经验证据和先前理论之间许多明显的矛盾。＊＊＊

Levitan 9411986 Post-zygotic mortality is considered to be the primary selective agent in the evolution of propagule size in many taxa, including marine invertebrates. Unfortunately, theoretical predictions of marine invertebrate egg size based on post-zygotic mortality have been difficult to test and are often at odds with the empirical data. This study will conduct a series of laboratory experiments that will measure egg size, sperm swimming ability, and fertilization rates, and a series of field experiments that will determine how these gamete attributes influence rates of fertilization under different environmental conditions. In one experiment , DNA fingerprints of single larva will provide answers to how specific gamete attributes influence rates of fertilization and mediate the outcome of sperm competition. Incorporating fertilization into a comprehensive life- history theory will resolve many of the apparent paradoxes between the empirical evidence and previous theories. ***