Offspring size effects mediate competitive interactions in a colonial marine invertebrate
Offspring size effects mediate competitive interactions in a colonial marine invertebrate
复制标题
DOI：
10.1890/05-0350
复制
发表时间：
2006-01-01
期刊：
影响因子：
4.8
通讯作者：
Emlet, RB
中科院分区：
文献类型：
--
作者：
Marshall, DJ;Cook, CN;Emlet, RB
在过去的30年里，人们进行了许多尝试来了解后代大小和适合度之间的关系，并且很明显，这种关键关系受到环境异质性的强烈影响。对于海洋无脊椎动物来说，人们对后代尺寸的进化一直很感兴趣，但对变质后后代尺寸效应的实证和理论研究很少，而且几乎没有人考虑环境异质性对后代尺寸/适合度关系的影响。我们在野外研究了种群海洋无脊椎动物Botrylloides violaceus后代大小的变质后效应。我们还研究了三种不同类型的种内竞争如何影响后代大小和表现之间的关系。我们发现后代的大小对生存和生长有强烈而持久的影响，但这种影响取决于种内竞争的水平和类型。一般来说，竞争强化了增加母体投资的优势。有趣的是，我们发现后代的大小决定了竞争相互作用的结果：拥有更多母亲投入的幼崽更有可能侵犯另一个幼崽的领地。这表明母亲具有以前未被认识到的影响底栖海洋无脊椎动物竞争相互作用结果的潜力。我们利用田间实验数据建立了一个简单的最优性模型，发现种内竞争的增加导致预测最优尺寸的增加。我们的研究结果表明，在海洋环境中，后代大小和适合度之间的关系是高度可变的，并且强烈依赖于同种鱼的密度。
Over the past 30 years, numerous attempts to understand the relationship between offspring size and fitness have been made, and it has become clear that this critical relationship is strongly affected by environmental heterogeneity. For marine invertebrates, there has been a long-standing interest in the evolution of offspring size, but there have been very few empirical and theoretical examinations of post-metamorphic offspring size effects, and almost none have considered the effect of environmental heterogeneity on the offspring size/fitness relationship. We investigated the post-metamorphic effects of offspring size in the field for the colonial marine invertebrate Botrylloides violaceus. We also examined how the relationship between offspring size and performance was affected by three different types of intraspecific competition. We found strong and persistent effects of offspring size on survival and growth, but these effects depended on the level and type of intraspecific competition.. Generally, competition strengthened the advantages of increasing maternal investment. Interestingly, we found that offspring size determined the outcome of competitive interaction: juveniles that had more maternal investment were more likely to encroach on another juvenile's territory. This suggests that mothers have the previously unrecognized potential to influence the outcome of competitive interactions in benthic marine invertebrates. We created a simple optimality model, which utilized the data generated from our field experiments, and found that increasing intraspecific competition resulted in an increase,in predicted optimal size. Our results suggest that the relationship between offspring size and fitness is highly variable in the marine environment and strongly dependent on the density of conspecifics.