Collaborative Research: Systematics and Adaptation of the Thaliacea (Tunicata): A Genetic and Morphological Study

合作研究：海囊纲（Tunicata）的系统学和适应：遗传和形态学研究

• 批准号: 0551419
• 负责人: Laurence Madin
• 金额: $ 23.65万
• 依托单位: Woods Hole Oceanographic Institution
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-04-15 至 2012-03-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0551419&HistoricalAwards=false
• 关键词: Collaborative; Research; Systematics; Adaptation; Thaliacea

The Thaliacea is a class of Tunicata comprising three groups of pelagic tunicates, the Pyrosomida, Doliolida and Salpida. All are free-swimming holoplanktonic organisms with complex life histories and prodigious capabilities as filter-feeding herbivores in the plankton. These three orders have worldwide distributions yet together number fewer than 100 described species. In some cases phenotypic variability has confused prior efforts at systematic classification and left open the possibility of cryptic species among many seemingly cosmopolitan forms. Existing classifications and phylogenies are all based on a limited number of morphological characters, which have been inadequate to resolve many questions about relationships at the genus and species level. Preliminary genetic evidence suggests that the Thaliacea are monophyletic within the Tunicata andthat salps, doliolids and pyrosomes are well-constrained monophyletic orders. However relationships below the ordinal are unclear, with some conflicts already arising between classical and molecular trees. Despite their global distribution and apparent ecological significance there arefew scientists today working on any aspect of Thaliacean biology. Partly this may be due to the difficulty for non-specialists in identifying species, particularly as specimens are often damaged in collection. This project brings together two molecular zoologists and one expert in Thaliacean ecology and life history. The research team will seek to reconcile morphological and genetic data to develop a phylogeny for the Thaliacea, based on data from as many of the described species as can be obtained, probably at least 70%. Because these groups are fairly small, this is a feasible goal, and will enable not only a well-supported consensus phylogeny and classification, but also a monographic treatment of the Class that will be useful for species identification by nonexperts. Broader impacts of the proposed research include the contribution of results to the global Census of Marine Zooplankton and the provision of a practical identification guide to Thaliacea for biological oceanographers. The project will support a postdoctoral investigator at WHOI and involve undergraduate students at the University of Connecticut. Project objectives and results will be made widely available via one or more websites hosted at WHOI or the University of Connecticut.

Thaliacea 是被囊动物门中的一类，包括三类远洋被囊动物：Pyrosomida、Doliolida 和 Salpida。它们都是自由游动的全浮游生物，具有复杂的生活史和浮游生物中滤食性草食动物的惊人能力。这三个目分布于世界各地，但所描述的物种总数不足 100 个。在某些情况下，表型变异混淆了先前的系统分类努力，并在许多看似世界性的形式中留下了神秘物种的可能性。现有的分类和系统发育都是基于有限数量的形态特征，不足以解决有关属和种水平关系的许多问题。初步的遗传证据表明，海藻纲在被囊纲中是单系的，而樽海鞘目、水体纲和火体纲是严格限制的单系目。然而，序数之下的关系尚不清楚，经典树和分子树之间已经出现了一些冲突。尽管它们分布于全球并具有明显的生态意义，但如今很少有科学家致力于海螺生物学的任何方面。部分原因可能是由于非专业人士难以识别物种，特别是标本在收集过程中经常遭到损坏。该项目汇集了两名分子动物学家和一名海螺生态学和生活史专家。研究小组将根据尽可能多（可能至少 70%）的所描述物种的数据，寻求协调形态学和遗传数据，以开发海螺科的系统发育学。因为这些群体相当小，所以这是一个可行的目标，不仅可以实现得到良好支持的共识系统发育和分类，而且可以对类别进行专题处理，这对于非专家的物种鉴定很有用。拟议研究的更广泛影响包括对全球海洋浮游动物普查结果的贡献以及为生物海洋学家提供海藻纲实用识别指南。该项目将支持 WHOI 的一名博士后研究员，并让康涅狄格大学的本科生参与其中。项目目标和结果将通过 WHOI 或康涅狄格大学托管的一个或多个网站广泛发布。