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

新罕布什尔大学的 Marianne Litvaitis 博士和 Richard Hochberg 先生获得了一笔资助，用于对澳大利亚和北美的胃毛虫进行首次比较解剖学分析。腹毛虫是一种鲜为人知的微生物群，广泛分布于世界各地的海洋中。大多数关于腹毛菌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。美国和澳大利亚对胃毛虫的解剖学知识仍处于起步阶段。因此，来自两个大陆的物种之间的关系尚不清楚。这项研究的主要目标是（1）描述几种新的澳大利亚腹毛虫，（2）利用体壁和肌肉系统的特征来确定澳大利亚和美洲物种之间的关系，以及（3）将此信息置于进化背景中。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的组合来分析样本。这项研究将重点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结构的变化如何促进微观动物群的扩散。这项研究的结果将为几种新的胃毛虫提供急需的分类学修订，并将深入了解胃毛虫的生物地理学和进化以及澳大利亚生物群的历史。随着对胃毛虫的解剖学知识的深入了解，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.