DISSERTATION RESEARCH: Developmental Ecology of Solitary and Colonial Ascidians

海鞘动物是一组全球分布的海洋无脊椎动物，可能是独居的，也可能是群居的。殖民主义在海鞘动物中进化了多次，并伴随着一系列相关的生殖特征。斯特拉斯曼和雅各布斯将通过比较独居和群居海鞘的生态和发育来研究繁殖策略的进化。他们的研究有望做出几项重要贡献。首先，关于独居和殖民地海囊动物早期生长和存活的初步数据质疑生活史策略的基本范式，包括鸡蛋大小、能量含量和后代健康之间的预测关系。海鞘是世界上常见的入侵物种，这项研究的能量部分将是及时调查潜在的幼虫寿命，从而研究传播潜力。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孤立海鞘，当它们是合格的幼虫时，能够进行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式系统和脊椎动物的近亲的发育如何工作的理解。最后，这项研究是将对重要发育转变的研究与对这些变化的功能生态后果的研究相结合的极少数研究之一。这一综合办法可作为今后研究生殖生态和发展演变的模式。

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.