DISSERTATION RESEARCH: Developmental Ecology of Solitary and Colonial Ascidians

海鞘是一种分布在全球的海洋无脊椎动物，可能是独居的，也可能是群体的。在海鞘中，殖民主义已经进化了多次，伴随着一套相关的生殖特征。Strathmann &amp； Jacobs将通过比较独居海鞘和群体海鞘的生态和发展来研究生殖策略的进化。他们的研究有望做出几项重要贡献。首先，关于孤立和群体海鞘的早期生长和生存的初步数据质疑了生活史策略的基本范式，包括卵大小、能量含量和后代适合度之间的预测关系。海鞘是世界范围内常见的入侵物种，本研究的能量学部分将是对潜在的幼虫寿命和传播潜力的及时调查。其次，初步的发育数据表明，以前被认为在扩散过程中处于发育停滞状态的独居海鞘，在它们是有能力的幼虫时，能够有意想不到的程度的分化和形态变化。这一发现有可能改变我们对这个日益重要的模型系统和脊椎动物的近亲如何发育的理解。最后，本研究是为数不多的将重要发育转变的研究与这些变化的功能生态后果的研究结合起来的研究之一。这种综合方法可以作为未来生殖生态学和发育进化研究的一个模式。

Ascidians are a globally distributed group of marine invertebrates which may be solitary or colonial. Colonialism has evolved multiple times in the ascidiacea, along with an associated suite of reproductive characters. Strathmann & Jacobs will investigate the evolution of reproductive strategies by comparing the ecology and development of solitary and colonial ascidians. Their study promises to make several important contributions. First, preliminary data on early growth and survival of solitary and colonial ascidians question basic paradigms of life history strategy, including predicted relationships between egg size, energy content, and offspring fitness. Ascidians are common invasive species worldwide, and the energetics portion of this study will be a timely investigation of potential larval lifespan and hence of dispersal potential. Second, preliminary development data suggest that solitary ascidians, previously thought to be in developmental stasis during dispersal, are capable of an unsuspected degree of differentiation and morphological change while they are competent larvae. This discovery has the potential to change our understanding of how development works in this increasingly important model system and close relative of vertebrates. Finally, this study is one of very few to combine investigations of important developmental transitions with studies of the functional ecological consequences of those changes. This integrative approach could serve as a model for future studies in reproductive ecology and the evolution of development.