DISSERTATION RESEARCH: Comparative Morphology of American and Australian Gastrotricha: the Muscular System as a Source of Taxonomic and Phylogenetic Characters

新汉普郡大学的Marianne Litvaitis博士和Richard Hochberg先生获得了一项资助，用于对澳大利亚和北美的胃毛进行第一次比较解剖学分析。胃毛虫是一类鲜为人知的微小蠕虫，在世界各地的海洋中都有发现。大多数关于腹毛虫多样性的知识仅限于北半球的物种，其中大部分是欧洲独有的。对美国和澳大利亚的胃毛的解剖学知识仍处于初级阶段。因此，这两个大陆的物种之间的关系是未知的。这项研究的主要目的是(1)描述几种新的澳大利亚胃毛动物，(2)利用体壁和肌肉系统的特征来确定澳大利亚和美国物种之间的关系，以及(3)将这些信息放在进化的背景下。标本将使用高分辨率光学显微镜、扫描和透射电子显微镜以及荧光显微镜进行分析。这项研究将突出使用新特征来测量无脊椎动物的生物多样性，并确定广泛分离的胃毛虫种群之间的进化关系。作为对肌肉系统的研究，它还将展示肌肉解剖的差异如何有助于微小动物的扩散。这项研究的结果将为几个新的腹毛纲动物提供急需的分类修订，并将深入了解腹毛纲的生物地理和进化以及澳大利亚生物群的历史。随着对胃毛的更多解剖学知识的了解，我们将更好地了解这一鲜为人知的无脊椎动物群体的生态和进化重要性。

A grant has been awarded to Dr. Marianne Litvaitis and Mr. Richard Hochberg of the University of New Hampshire to conduct the first comparative anatomical analysis of gastrotrichs from Australia and North America. Gastrotrichs are a poorly known group of microscopic worms found throughout the world's oceans. Most knowledge of gastrotrich diversity is limited to species from the Northern Hemisphere, and much of this is exclusive to Europe. Anatomical knowledge of gastrotrichs from the United States and Australia remains in its infancy. Consequently, relationships between species from both continents are unknown. The principle objectives of this research are (1) to describe several new Australian gastrotrichs, (2) use characteristics of the body-wall and muscular system to determine relationships between Australian and American species, and (3) to place this information in an evolutionary context. Specimens will be analyzed using a combination of high-resolution light microscopy, scanning and transmission electron microscopy, and fluorescence microscopy.This research will highlight the use of novel characters to measure invertebrate biodiversity and determine evolutionary relationships among widely separated populations of gastrotrichs. As a study of the muscular system, it will also demonstrate how variation in muscle anatomy contributes to dispersal of microscopic fauna. Results from this research will provide much-needed taxonomic revisions of several new gastrotrichs and will yield insight into the biogeography and evolution of the Gastrotricha and the history of the Australian biota. With a greater anatomical knowledge of gastrotrichs, we will gain better insights into the ecological and evolutionary importance of this poorly known group of invertebrates.